ALBERT

Beschreibung: Abstract Population monitoring must be accurate and reliable to correctly classify population status. For sea turtles, nesting beach surveys are often the only population‐level surveys that are accessible. However, process and observation errors, compounded by delayed maturity, obscure the relationship between trends on the nesting beach and the population. We present a simulation‐based tool, monitoring strategy evaluation (MoSE), to test the relationships between monitoring data and assessment accuracy, using green sea turtles, Chelonia mydas, as a case study. To explore this first application of MoSE, we apply different treatments of population impacts to virtual true populations, and sample the nests or nesters, with observation error, to test if the observation data can be used to diagnose population status accurately. Based on the observed data, we examine population trend and compare it to the known values from the operating model. We ran a series of scenarios including harvest impacts, cyclical breeding probability, and sampling biases, to see how these factors impact accuracy in estimating population trend. We explored the necessary duration of monitoring for accurate trend estimation and the probability of a false trend diagnosis. Our results suggest that disturbance type and severity can have important and persistent effects on the accuracy of population assessments drawn from monitoring nesting beaches. The underlying population phase, age classes disturbed, and impact severity influenced the accuracy of estimating population trend. At least 10 yr of monitoring data is necessary to estimate population trend accurately, and 〉20 yr if juvenile age classes were disturbed and the population is recovering. In general, there is a greater probability of making a false positive trend diagnosis than a false negative, but this depends on impact type and severity, population phase, and sampling duration. Improving detection rates to 90% does little to lower probability of a false trend diagnosis with shorter monitoring spans. Altogether, monitoring strategies for specific populations may be tailored based on the impact history, population phase, and environmental drivers. The MoSE is an important framework for analysis through simulation that can comprehensively test population assessments for accuracy and inform policy recommendations regarding the best monitoring strategies.

Beschreibung: Ecological Applications, Volume 29, Issue 5, July 2019.

Beschreibung: Abstract The research aims to evaluate the output of biogas and the concentration of CH4 and gaseous impurities such as CO2 and H2S in the process of digesting chicken manure without additives (experiment A) and with 10% of biochar additive (by mass of the dry load) (experiment B) under anaerobic and mesophilic conditions. It has been found that the average output of biogas from a particular amount of chicken manure (experiments A and B) obtained in the 45‐day experimental research is similar in both cases and reaches 12.88 l d–1 and 12.36 l d–1, respectively. However, the biochar additive increases CH4 concentration in biogas and reduces the concentration of gaseous impurities (CO2 and H2S) in biogas. The maximum concentration of CH4 in biogas obtained from a load of manure with biochar additive is higher than that in biogas obtained by using a load without a biochar additive, and reaches 72.0% and 68.5%, respectively. The average CO2 concentration, reaching 33.09% and 47.5%, respectively, in biogas obtained from the load with 10% of biochar additive is lower than that in biogas obtained from the manure load without an additive. The average concentration of H2S in the biogas obtained in experiment B is lower than that in experiment A and reaches 95.9 mg m–3 and 195.5 mg m–3, respectively. The biochar additive adsorbs gaseous impurities (CO2 and H2S) from biogas without adsorbing CH4. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Revegetation of pioneer plants is a critical phase in community establishment for mudflats in seriously degraded coastal wetlands. We tested a hypothesis of the importance of a “power balance” among propagule resilience and sedimentary and tidal disturbances for vegetation reestablishment. Our experiment used three types of propagules (seeds, seedlings, and corms) of native Scirpus species in the fringing flats with similar tidal flows and varying sedimentary intensities in the Yangtze Estuary. Regardless of the initial planting densities, the seed germination rate was extremely low in the field situation. Although the incubated seedlings were planted directly on the bare flat, the wave movement easily flushed the seedlings, even at the site with moderate sedimentary accretion. Failure of the revegetation practice using the seed and seedling materials indicated that the combined “growing and anchoring power” of young seedlings and “stabilizing power” of the sediment were insufficient to withstand the “dislodging power” of the tidal energy. In contrast, the planting approach with underground propagules (corms) proved to be feasible for vegetation establishment at the sites with moderate and low‐level sedimentary intensities. The successful practice improved the tipping point of plant survival and tussock formation could be surpassed when the combined growing and anchoring power of seedlings that developed from corms with the stabilizing power of the sediment was greater than the dislodging power of the wave energy. However, at the site with high‐level sedimentary intensity, the excessive sediment converted to the burying stress power as seedlings developed from the corms, revealing a burial threshold for seedling survival. The risk of seedling establishment was high when the burying stress power of the sediment far outweighed the combination of the growing power of the seedlings and the sediment removal power of the tidal current and surpassed the tipping point of vegetation die‐off. Additionally, we checked the practice cost of the different approaches to ensure a highly cost‐effective revegetation planning based on site suitability. This study highlights that understanding of the propagule–sediment–tide power balance offers a tool for improvement of the revegetation and management of site‐specific sedimentary and hydrological environments for many degraded coastal ecosystems.

Beschreibung: Abstract Inorganic membranes can operate under harsh conditions. However, successful synthesis of inorganic membranes is still challenging, and its performance depends on many factors. This work reports the effect of dip‐coating duration, inlet pressure, and inlet flow rate on the flux, permeability, and selectivity of silica membranes. A silica membrane was prepared by the deposition of silica sol onto porous alumina support. The permeability test was conducted at 100 °C using a single gas of CO2 and CH4. The highest flux was observed at the maximum inlet pressure and inlet flow rate for the membrane prepared at the minimum dip‐coating duration. The neural network modeling of the membrane predicted permeabilities showed a considerably high validity regression (R ≈ 0.99) of the predicted data linked to the experimental sets. The separation factor (α) was the highest at the maximum dip‐coating duration. The synthesized silica membrane has potential for CO2/CH4 separation under harsh operating conditions. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract The concentration of greenhouse gases (GHG)s and specifically CO2 continue to rise in the global environment including the atmosphere and the oceans. Oil and gas exploration in oceans and the increased probability of CO2 being destined for ocean storage have made the oceans much vulnerable to acidification and hence detrimental to the entire marine ecosystem. Offshore wind energy, along with other renewables, have the potential to lower the rate of CO2 absorption in the global eco system. Distant offshore wind farms are faced with the problem of dispatch of surplus wind power. Power‐to‐gas technology can be used to convert the offshore wind power into synthetic natural gas that can be transported through the existing network of offshore gas pipelines. The novel method has the capability to significantly reduce GHG emissions, solve the power dispatch problems of offshore wind farms, as well as reduce the oceanic environmental degradation. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Controlled release of carbon dioxide (CO2) into the soil and atmosphere is performed to test detection and monitoring tools, for which several field laboratories were established by a number of institutions worldwide. Numerical simulations of CO2 behavior in the shallow subsurface region are other forms of validation and verification of the leakage pathways and destinations. These studies aim to improve monitoring and verification of CO2 in case of unexpected leakages for public assurance. In this work, we present the results of a numerical modeling study conducted to simulate the injection of CO2 as carried out during a field test in Viamão, southern Brazil, where 20 kg day–1 of CO2 was pumped for 30 days through a vertical well 3 m below ground in an altered granitic soil. Multiphase flow simulations were performed with the TOUGH2/EOS7CA software for unsaturated porous media, using field data and injection parameters, including sensitivity tests to permeability direction, diffusivity, and boundary conditions. Results with increased horizontal permeabilities are in better agreement with the field observations. In this condition, mass balance calculations indicate approximately 90% of injected CO2 (20 kg day–1 during 30 days) remains in the soil after 180 days from injection start, consistent with the measured flow through the soil–atmosphere interface. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract In order to utilize as much of the pore space for CO2 storage in high permeability thick saline aquifers, it is vital to investigate the interactions of injected CO2 with formation brine and rock. In order to quantify the displacement process, we investigate the dynamic storage efficiency factor (DSEF) for saline aquifers where pressure increase is minimal during the injection phase. Dimensionless numbers are derived from basic governing equations, constitutive equations, initial and boundary conditions using the inspection analysis. Then using the Hammersley sequence sampling, 178 numerical experiments are designed, and a compositional reservoir simulator is used to perform these simulations. In the next step, response surface regression analysis is used to establish a relationship between DSEF obtained from the numerical simulations and the corresponding dimensionless numbers. The simulation results show that for the studied conditions the underground dynamics is mostly influenced by the gravity number, followed by effective aspect ratio and dip numbers. The results from the response surface regression analysis are used to develop a correlation, which can be used to estimate the dynamic CO2 storage capacity of relevant zones. This study provides quantitative measures for the different competing mechanisms involved in underground displacement of fluids in CO2 geological storage, which can serve as a useful tool during planning phase of storage projects. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Greenhouse Gases: Science and Technology, Volume 9, Issue 4, Page 610-612, August 2019.

Beschreibung: Abstract The phase equilibria with the confinement effect could shift in nano‐pores, which could have a great impact on the recovery mechanisms of CO2 injection in tight oil reservoirs; this has not been systematically studied. In this paper, the confinement effect with property shift and capillarity effect is introduced into the flash calculation of confined fluids. The Soave modification of the Redlich–Kwong equation of state is extended by the molecular‐wall collision parameter to describe the shifted pressure–volume–temperature properties of confined fluid, and the Young–Laplace equation is applied to evaluate the capillary pressure. This developed model could effectively be applied for phase equilibrium calculation in tight porous media because of the verification of experimental results. A binary mixture is investigated to study the different effect of capillary pressure and property shift on phase equilibria. Subsequently, a typical hydrocarbon fluid from Middle Bakken tight oil reservoirs is studied with CO2 injection. Results illustrate that the confinement effect could play an increasingly important part in the phase equilibrium state. The CO2 solubility and mass transfer driving force in tiny pores would be greater than those in large pores under the same conditions. The gas phase saturation would be smaller with the same compositions, which could extend the single‐phase region of fluid flow in porous media. Furthermore, bubble‐point pressure, the minimum miscible pressure of CO2/hydrocarbon, and the viscosity of tight oil dissolved with CO2 both decrease with the pore size, which has a good influence on tight oil recovery. In general, the confinement effect could effectively reinforce the recovery mechanisms of CO2 injection, which is conducive to the enhancement of tight oil recovery. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Recent field experiments in Iceland and Washington State (USA) show that basalt formations may be favorable targets for carbon capture and sequestration (CCS) because CO2 mineralization reactions proceed rapidly. These results imply that there is tremendous opportunity for implementing CCS in large igneous provinces. However, the magnitude of this opportunity comprises commensurate levels of uncertainty because basalt reservoirs are characterized by highly heterogeneous, fracture‐controlled hydraulic properties. This geologic uncertainty is propagated as parametric uncertainty in quantitative risk models, thus limiting the efficacy of models to predict CCS performance attributes, such as reservoir integrity and storage potential. To overcome these limitations, this study presents a stochastic approach for quantifying the geomechanical performance attributes of CCS operations in a highly heterogeneous basalt reservoir. We utilize geostatistical reservoir characterization to develop an ensemble of equally probable permeability distributions in a flood basalt reservoir with characteristics of the Wallula Basalt Pilot Project. We then simulate industrial‐scale CO2 injections within the ensemble and calculate the mean and variance of fluid pressure over a 1‐year injection period. These calculations are combined with the state of stress in southeast Washington State to constrain the spatial extent at which shear failure, fracture initiation, and borehole breakdown may occur. Results from this study show that (i) permeability uncertainty alone causes injection pressure to vary over 25 MPa, (ii) shear failure is likely to occur at 7 times greater distances from the injection than the CO2 migrates, and (iii) joint initiation pressures are localized within the volume comprising the CO2 plume. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Despite political turmoil and intrigue, along with the inevitable financial uncertainty, the desire to overcome the obstacles that could hold back the innovation and implementation of technologies and projects to tackle climate change remains active. The recent climate change protests by school children are an indicator of not only the level of concern over climate issues, but what is also at stake if these obstacles allow progress to be derailed. The good news is that in the area of carbon capture utilisation and storage (CCUS), considered to be among the costliest, but necessary, weapons in the climate change mitigation arsenal, progress continues to be made. In this article, GHGS&T's Muriel Cozier rounds up some of the most recent developments. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Modern forest management seeks to balance multiple social, economic, and ecological goals. Different management approaches create different types of disturbances in a forest ecosystem, and thus also differ in their impacts on plants, animals, and insects. Understanding these impacts is important for conservation of forest ecosystem function, but challenging due to the large spatial and temporal scale over which management occurs. Most past research has focused on relatively small areas, short time scales, and/or a small number of species. To address this, we examined the effects of two common silvicultural systems (even‐ and uneven‐aged) on abundance and richness of three vertebrate taxa (birds, small mammals, and herpetofauna) over a two‐decade period in a temperate hardwood forest in Missouri, USA. The two systems removed a similar amount of biomass overall, but differed in the intensity, number, and configuration of harvests applied. We found that vertebrate population responses varied by taxa, occurred at multiple spatial scales, and were concentrated in the period following the first harvest entry. Birds generally had the largest changes in relative abundance, both positive and negative, following management. Small mammals and reptiles had smaller, but generally positive, responses; amphibians were mixed. Bird species tended to respond in the same way to both silvicultural systems, while small mammals and herpetofauna did not respond consistently. Thus, for birds, the total amount of harvest disturbance across the landscape drives population responses, while for others the size and configuration of individual harvests is likely more important. Synthesizing results across the vertebrate community at large spatial and temporal scales allows managers to better understand tradeoffs when making decisions that will affect wildlife in contrasting ways. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract To investigate the flow field near fracture entrance and promote the development of sand fracturing with carbon dioxide as the working fluid, numerical simulation of multiphase flow was conducted with a 3D geological model considering the compressibility of carbon dioxide. The flow field of carbon dioxide alone was firstly investigated to lay the foundation for the analysis of multiphase flow, and then comparative analysis was conducted on the flow field of both the injecting sand from the pipe and the annulus. The results show that jet fracture with carbon dioxide can achieve a 4.46 MPa pressure boost at the fracture tip compared to the annulus pressure, which theoretically validates the feasibility of the mentioned technology. Sand fracturing can achieve a higher pressure boost in the cavity, while it needs greater pump pressure at the surface. Injecting sand from the annulus could decrease the need for pump pressure by 6.62 MPa at the condition of injecting 25% carbon dioxide from the annulus simultaneously, while the pressure difference between the cavity tip and the annulus decreases as a result. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Global warming and the greenhouse effect are two of the most important environmental problems. Carbon dioxide, methane, and nitrous oxide emissions are the main greenhouse gas emissions in wastewater treatment plants. In this study, the greenhouse gas emission sources in a wastewater treatment plant were determined. Direct (from fossil fuel combustion, methane emissions, and process emissions of the other greenhouse gases) and indirect emissions (primarily from electricity use) in the plant were monitored. The optimum influent characteristics and operating conditions have been defined by using Monte Carlo simulation to minimize the emissions. The results revealed that the highest direct greenhouse gas emission was observed in August with the value of 23.328 kg CO2‐eq d–1 and the lowest emission was 7.56 kg CO2‐eq d–1 measured in January. The aeration tank is a major source of greenhouse gas emissions. Indirect emission has occurred because of the anaerobic digester but the biogas has been cogenerated in the plant, so it has been ignored for the calculation. According to the simulation study, if the plant is operated under optimum operating conditions, it can emit the lowest amount of greenhouse gas emissions. The optimum removal values required for the minimum greenhouse gas emissions are 79% for chemical oxygen demand, 75% for biochemical oxygen demand, and 82% for total suspended solid. The optimum operating conditions for the aeration tank, which is the major source of emission, are 5.33 h of hydraulic retention time, 0.215 d of solid retention time, and 0.999 for food/microorganisms. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Greenhouse Gases: Science and Technology, Volume 9, Issue 4, Page 607-609, August 2019.

Beschreibung: The cover image is based on the Review Renewable absorbents for CO2 capture: from biomass to nature by Qingyao He et al., https://doi.org/10.1002/ghg.1902. Cover image © Feihong Liang.

Beschreibung: Abstract For the past six decades since 1960 the oriental fruit fly, Bactrocera dorsalis (Hendel), has been announced successfully eradicated in California by the US Department of Agriculture for a total of 564 times. This includes eradication declarations in 1 city a total of 25 different years, in 12 cities 8 to 19 different years, and in 101 cities 2 to 7 different years. We here show that the false negatives in declaring elimination success hinge on the easily‐achieved regulatory criteria, which have virtually guaranteed the failure of complete extirpation of this pest. Analyses of the time series of fly detection over California gridded into 100 km2 cells revealed, (1) partial success of eradication program in controlling the invasion of the oriental fruit fly; (2) low prevalence of the initial detection in these cells is often followed by high prevalence of recurrences; (3) progressively shorter intervals between years of consecutive detections; and (4) high likelihood of early‐infested cells also experiencing the most frequent outbreaks. Facing the risk of recurrent invasions, such short‐term eradication programs have only succeeded annually according to the current regulatory criteria but have failed to achieve the larger goal of complete extirpation of the oriental fruit fly. Based on the components and running costs of the current programs, we further estimated the efficiency of eradication programs with different combinations of eradication radius, duration, and edge impermeability in reducing invasion recurrences and slowing the spread of the oriental fruit fly. We end with policy implications including the need for agricultural agencies worldwide to revisit eradication protocols in which monitoring and treatments are terminated when the regulatory criteria for declaring eradication are met. Our results also have direct implications to invasion biologists and agriculture policy makers regarding long‐term risks of short‐term expediency. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract I read with interest the paper by Benson et al. (2019), wherein the authors noted that conserving mountain lions in the Santa Monica and Santa Ana mountains, both located in the greater Los Angeles area of California, is feasible. The authors further explained that such an accomplishment would be an important step toward maintaining, “…intact, functioning ecosystems…within one of the most human‐impacted landscapes in the world” and emphasized the role of mountain lions in, “…maintain[ing] stable predator‐prey dynamics and naturally functioning ecosystems within these isolated mountain ranges”. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract The Global Eradication Database documents 811 eradication attempts against invasive arthropods since 1890, in 104 countries. Eradication programs show a greater than exponential increase in the number of programs started in recent decades. In addition, there is a trend of a rapidly diversifying burden of the most severe threats. The species richness showed a three‐fold increase in number of species under eradication in the last 50 yr, and all taxonomic levels rose dramatically. The increase in number of eradication programs shows that current management measures for constraining the spread of invasive species are inadequate. A similar surge in the number of governments trying to prevent the establishment of new pests has occurred. Increased biodiversity of arthropod eradication targets includes new pest groups with fewer tools developed for management. We argue that a rapid increase in biodiversity of invasive and economically or environmentally damaging organisms represents a substantial and underestimated challenge for managers wanting to prevent their establishment, requiring a shift in research focus to accelerate delimitation and suppression options with less reliance on insecticides.

Beschreibung: Abstract Species‐focused conservation planning is often based on reducing local extinction risk at key sites. However, with increasing levels of habitat fragmentation and pressures from climate change and overexploitation, surrounding landscapes also influence the persistence of species populations, and their effects are increasingly incorporated in conservation planning and management for both species and communities. Here, we present a framework based on metapopulation dynamics in fragmented landscapes, for quantifying the survival (resistance) and reestablishment of species populations following localized extinction events (resilience). We explore the application of this framework to guide the conservation of a group of threatened bird species endemic to papyrus (Cyperus papyrus) swamps in East and Central Africa. Using occupancy data for five species collected over two years from a network of wetlands in Uganda, we determine the local and landscape factors that influence local extinction and colonization, and map expected rates of population turnover across the network to draw inferences about the locations that contribute most to regional resistance and resilience for all species combined. Slight variation in the factors driving extinction and colonization between individual papyrus birds led to species‐specific differences in the spatial patterns of site‐level resistance and resilience. However, despite this, locations with the highest resistance and/or resilience overlapped for most species and reveal where resources could be invested for multispecies persistence. This novel simplified framework can aid decision making associated with conservation planning and prioritization for multiple species residing in overlapping, fragmented habitats; helping to identify key sites that warrant urgent conservation protection, with consideration of the need to adapt and respond to future change.

Beschreibung: Abstract Foraging mammalian predators face a myriad of odors from potential prey. To be efficient, they must focus on rewarding odors while ignoring consistently unrewarding ones. This may be exploited as a nonlethal conservation tool if predators can be deceived into ignoring odors of vulnerable secondary prey. To explore critical design components and assess the potential gains to prey survival of this technique, we created an individual‐based model that simulated the hunting behavior of three introduced mammalian predators on one of their secondary prey (a migratory shorebird) in the South Island of New Zealand. Within this model, we heuristically assessed the outcome of habituating the predators to human‐deployed unrewarding bird odors before the bird's arrival at their breeding grounds, i.e., the predators were “primed.” Using known home range sizes and probabilities of predators interacting with food lures, our model suggests that wide‐ranging predators should encounter a relatively large number of odor points (between 10 and 115) during 27 d of priming when odor is deployed within high‐resolution grids (100–150 m). Using this information, we then modeled the effect of different habituation curves (exponential and sigmoidal) on the probability of predators depredating shorebird nests. Our results show that important gains in nest survival can be achieved regardless of the shape of the habituation curve, but particularly if predators are fast olfactory learners (exponential curve), and even if some level of dishabituation occurs after prey become available. Predictions from our model can inform the amount and pattern in which olfactory stimuli need to be deployed in the field to optimize encounters by predators, and the relative gains that can be expected from reduced predation pressure on secondary prey under different scenarios of predator learning. Habituating predators to odors of threatened secondary prey may have particular efficacy as a conservation tool in areas where lethal predator control is not possible or ethical, or where even low predator densities can be detrimental to prey survival. Our approach is also relevant for determining interaction probabilities for devices other than odor points, such as bait stations and camera traps.

Beschreibung: Abstract Forest harvest in the boreal zone can increase the input of terrestrial materials such as dissolved organic carbon (DOC) and nitrate (NO3−) into nearby aquatic ecosystems, with potential effects on phytoplankton growth through enhanced nutrient (i.e., positive) or reduced light availability (i.e., negative), which may affect ecosystem productivity and consumer resource use. Here, we conducted forest clear‐cutting experiments in the catchments of four small, humic, and nitrogen‐limited unproductive boreal lakes (two controls and two clear‐cut, 18% and 44% of area cut) with one reference and two impact years. Our aim was to assess the effects of forest clear‐cutting on pelagic biomass production and consumer resource use. We found that pelagic biomass production did not change after two years of forest clear‐cutting: Pelagic primary and bacterial production (PP, BP), PP:BP ratio, chl a, and seston carbon (seston C) were unaffected by clear‐cutting; neither did tree harvest affect seston stoichiometry (i.e., N:phosphorus [P], C:P) nor induce changes in zooplankton resource use, biomass, or community composition. In conclusion, our findings suggest that pelagic food webs of humic lakes (DOC 〉 15 mg/L) might be resilient to a moderate form of forest clear‐cutting, at least two years after tree removal, before mechanical site preparation (e.g., mounding, plowing) and when leaving buffer strips along lakes and incoming streams. Thus, pelagic food web responses to forest clear‐cutting might not be universal, but could depend on factors such as the time scale, share of catchment logged, and the forest practices involved, including the application of buffer strips and site preparation.

Beschreibung: Abstract Reintroducing a species to an ecosystem can have significant impacts on the recipient ecological community. Although reintroductions can have striking and positive outcomes, they also carry risks; many well‐intentioned conservation actions have had surprising and unsatisfactory outcomes. A range of network‐based mathematical methods has been developed to make quantitative predictions of how communities will respond to management interventions. These methods are based on the limited knowledge of which species interact with each other and in what way. However, expert knowledge isn't perfect and can only take models so far. Fortunately, other types of data, such as abundance time series, is often available, but, to date, no quantitative method exists to integrate these various data types into these models, allowing more precise ecosystem‐wide predictions. In this paper, we develop mathematical methods that combine time‐series data of multiple species with knowledge of species interactions and we apply it to proposed reintroductions at Booderee National Park in Australia. There have been large fluctuations in species abundances at Booderee National Park in recent history, following intense feral fox (Vulpes vulpes) control, including the local extinction of the greater glider (Petauroides volans). These fluctuations can provide information about the system isn't readily obtained from a stable system, and we use them to inform models that we then use to predict potential outcomes of eastern quoll (Dasyurus viverrinus) and long‐nosed potoroo (Potorous tridactylus) reintroductions. One of the key species of conservation concern in the park is the Eastern Bristlebird (Dasyornis brachypterus), and we find that long‐nosed potoroo introduction would have very little impact on the Eastern Bristlebird population, while the eastern quoll introduction increased the likelihood of Eastern Bristlebird decline, although that depends on the strength and form of any possible interaction.

Beschreibung: Abstract This research investigates ecological responses to drought by developing a conceptual framework of vegetation response and investigating how multiple measures of drought can improve regional drought monitoring. We apply this approach to a case study of a recent drought in Guanacaste, Costa Rica. First, we assess drought severity with the Standard Precipitation Index (SPI) based on a 64‐yr precipitation record derived from a combination of Global Precipitation Climatology Center data and satellite observations from Tropical Rainfall Measuring Mission and Global Precipitation Measurement. Then, we examine spatial patterns of precipitation, vegetation greenness, evapotranspiration (ET), potential evapotranspiration (PET), and evaporative stress index (ESI) during the drought years of 2013, 2014, and 2015 relative to a baseline period (2002–2012). We compute wet season (May–October) anomalies for precipitation at 0.25° spatial resolution, normalized difference vegetation index (NDVI) at 30‐m spatial resolution, and ET, PET and ESI derived with the Priestley‐Taylor Jet Propulsion Laboratory (PT‐JPL) model at 1‐km spatial resolution. We assess patterns of landscape response across years and land cover types including three kinds of forest (deciduous, old growth, and secondary), grassland, and cropland. Results show that rainfall in Guanacaste reached an all‐time low in 2015 over a 64‐yr record (wet season SPI = −3.46), resulting in NDVI declines. However, ET and ESI did not show significant anomalies relative to a baseline, drought‐free period. Forests in the region exhibited lower water stress compared to grasslands and had smaller declines, and even some increases, in NDVI and ET during the drought period. This work highlights the value of using multiple measures to assess ecosystem responses to drought. It also suggests that agricultural land management has an opportunity to integrate these findings by emulating some of the characteristics of drought‐resilient ecosystems in managed systems.

Beschreibung: Ecological Applications, EarlyView.

Beschreibung: Abstract Nutrient inputs to surface waters are particularly varied in urban areas, due to multiple nutrient sources and complex hydrologic pathways. Because of their close proximity to coastal waters, nutrient delivery from many urban areas can have profound impacts on coastal ecology. Relatively little is known about the temporal and spatial variability in stoichiometry of inorganic nutrients such as dissolved silica, nitrogen, and phosphorus (Si, N, and P) and dissolved organic matter in tropical urban environments. We examined nutrient stoichiometry of both inorganic nutrients and organic matter in an urban watershed in Puerto Rico served by municipal sanitary sewers and compared it to two nearby forested catchments using samples collected weekly from each river for 6 yr. Urbanization caused large increases in the concentration and flux of nitrogen and phosphorus (2‐ to 50‐fold), but surprisingly little change in N:P ratio. Concentrations of almost all major ions and dissolved silica were also significantly higher in the urban river than the wildland rivers. Yield of dissolved organic carbon (DOC) was not increased dramatically by urbanization, but the composition of dissolved organic matter shifted toward N‐rich material, with a larger increase in dissolved organic nitrogen (DON) than DOC. The molar ratio of DOC:DON was about 40 in rivers draining forested catchments but was only 10 in the urban river. Inclusion of Si in the assessment of urbanization's impacts reveals a large shift in the stoichiometry (Si:N and Si:P) of nutrient inputs. Because both Si concentrations and watershed exports are high in streams and rivers from many humid tropical catchments with siliceous bedrock, even the large increases in N and P exported from urban catchments result in delivery of Si, N, and P to coastal waters in stoichiometric ratios that are well in excess of the Si requirements of marine diatoms. Our data suggest that dissolved Si, often neglected in watershed biogeochemistry, should be included in studies of urban as well as less developed watersheds due to its potential significance for marine and lacustrine productivity.

Beschreibung: Abstract Instantaneous implementation of systematic conservation plans at regional scales is rare. More typically, planned actions are applied incrementally over periods of years or decades. During protracted implementation, the character of the connected ecological system will change as a function of external anthropogenic pressures, local metapopulation processes, and environmental fluctuations. For heavily exploited systems, habitat quality will deteriorate as the plan is implemented, potentially influencing the schedule of protected area implementation necessary to achieve conservation objectives. Understanding the best strategy to adopt for applying management within a connected environment is desirable, especially given limited conservation resources. Here, we model the sequential application of no‐take marine protected areas (MPAs) in the central Philippines within a metapopulation framework, using a range of network‐based decision rules. The model was based on selecting 33 sites for protection from 101 possible sites over a 35‐yr period. The graph‐theoretic network criteria to select sites for protection included PageRank, maximum degree, closeness centrality, betweenness centrality, minimum degree, random, and historical events. We also included a dynamic strategy called colonization–extinction rate that was updated every year based on the changing capacity of each site to produce and absorb larvae. Each rule was evaluated in the context of achieving the maximum metapopulation mean lifetime at the conclusion of the implementation phase. MPAs were designated through the alteration of the extinction risk parameter. The highest ranked criteria were PageRank while the actual implementation from historical records ranked lowest. Our results indicate that protecting the sites ranked highest with regard to larval supply is likely to yield the highest benefit for fish abundance and fish metapopulation persistence. Model results highlighted the benefits of including network processes in conservation planning.

Beschreibung: Abstract Before‐After‐Control‐Impact (BACI) designs are powerful tools to derive inferences about environmental perturbations (e.g., hurricanes, restoration programs) when controlled experimental designs are unfeasible. Applications of BACI designs mostly rely on testing for a significant interaction between periods and treatments (so‐called BACI contrast) to demonstrate the effects of the perturbation. However, significant interactions can emerge for several reasons, including when changes are larger in control sites, such that additional diagnostics must be performed to determine the full complexity of system changes. We propose two measures that detail the nature of change implied by BACI contrasts, along with its uncertainty. CI‐divergence (Control‐Impact divergence) quantifies to what extent control and impact sites have diverged between the after and the before period, whereas CI‐contribution (Control‐Impact contribution) quantifies to what extent the change between periods is stronger in impact sites relative to control sites. To illustrate how these two CI measures can be combined with BACI contrast to gain insights about effects of environmental perturbations, we used count data from the Swedish Breeding Bird Survey to investigate how hurricane Gudrun affected the long‐term abundances of four bird species in forested areas of southern Sweden. Before‐After‐Control‐Impact contrasts suggested the hurricane affected all four species. However, the values of the two CI measures strongly differed, even among species showing similar BACI contrasts. Those differences highlight qualitatively distinct population trajectories between periods and treatments requiring different ecological explanations. Overall, we show that BACI contrasts do not provide the full story in assessing the effects of environmental perturbations. The two CI measures can be used to assist ecological interpretations, or to specify detailed hypotheses about effects of restoration actions to allow stronger confirmatory inference about their outcomes. By providing a framework to develop more detailed explanations and hypotheses about ecological changes, the two CI measures can improve conclusions and strengthen evidence of effects of conservation actions and impact assessments under BACI designs.

Beschreibung: Abstract The future trajectory of atmospheric CO2 concentration depends on the development of the terrestrial carbon sink, which in turn is influenced by forest dynamics under changing environmental conditions. An in‐depth understanding of model sensitivities and uncertainties in non‐steady‐state conditions is necessary for reliable and robust projections of forest development and under scenarios of global warming and CO2 enrichment. Here, we systematically assessed if a biogeochemical process‐based model (3D‐CMCC‐CNR), which embeds similarities with many other vegetation models, applied in simulating net primary productivity (NPP) and standing woody biomass (SWB), maintained a consistent sensitivity to its 55 input parameters through time, during forest ageing and structuring as well as under climate change scenarios. Overall, the model applied at three contrasting European forests showed low sensitivity to the majority of its parameters. Interestingly, model sensitivity to parameters varied through the course of 〉100 yr of simulations. In particular, the model showed a large responsiveness to the allometric parameters used for initialize forest carbon and nitrogen pools early in forest simulation (i.e., for NPP up to ~37%, 256 g C·m−2·yr−1 and for SWB up to ~90%, 65 Mg C/ha, when compared to standard simulation), with this sensitivity decreasing sharply during forest development. At medium to longer time scales, and under climate change scenarios, the model became increasingly more sensitive to additional and/or different parameters controlling biomass accumulation and autotrophic respiration (i.e., for NPP up to ~30%, 167 g C·m−2·yr−1 and for SWB up to ~24%, 64 Mg C/ha, when compared to standard simulation). Interestingly, model outputs were shown to be more sensitive to parameters and processes controlling stand development rather than to climate change (i.e., warming and changes in atmospheric CO2 concentration) itself although model sensitivities were generally higher under climate change scenarios. Our results suggest the need for sensitivity and uncertainty analyses that cover multiple temporal scales along forest developmental stages to better assess the potential of future forests to act as a global terrestrial carbon sink.

Beschreibung: Abstract Artificial lighting at night (ALAN) is a global phenomenon that can be detrimental to organisms at individual and population levels, yet potential consequences for communities and ecosystem functions are less resolved. Riparian systems may be particularly vulnerable to ALAN. We investigated the impacts of ALAN on invertebrate community composition and food web characteristics for linked aquatic‐terrestrial ecosystems. We focused on food chain length (FCL), a central property of ecological communities that can influence their structure, function, and stability; and the contribution of aquatically derived energy (i.e., nutritional subsidies originating from stream periphyton). We collected terrestrial arthropods and emergent aquatic insects from a suite of stream and wetland sites in Columbus, Ohio, USA. Stable isotopes of carbon (13C) and nitrogen (15N) were used to infer FCL and contribution of aquatically derived energy. We found that moderate‐to‐high levels of ALAN altered invertebrate community composition, favoring primarily predators and detritivores. Impacts of ALAN, however, were very taxon specific as illustrated, for example, by the negative impact of ALAN on the abundance of orb‐web spiders belonging to the families Tetragnathidae and Araneidae: key invertebrate riparian predators. Most notably, we observed decreases in both invertebrate FCL and reliance on aquatically derived energy under ALAN (although aquatic energetic contributions appeared to increase again at higher levels of ALAN), in addition to shifts in the timing of reciprocal nutritional subsidies. Our study demonstrates that ALAN can alter the flows of energy between aquatic and terrestrial systems, thereby representing an environmental perturbation that can cross ecosystem boundaries. Given projections for global increases in ALAN, both in terms of coverage and intensity, these results have broad implications for stream ecosystem structure and function.

Beschreibung: Abstract Downed coarse woody debris, also known as coarse woody detritus or downed dead wood, is challenging to estimate for many reasons, including irregular shapes, multiple stages of decay, and the difficulty of identifying species. In addition, some properties are commonly not measured, such as wood density and carbon concentration. As a result, there have been few previous evaluations of uncertainty in estimates of downed coarse woody debris, which are necessary for analysis and interpretation of the data. To address this shortcoming, we quantified uncertainties in estimates of downed coarse woody debris volume and carbon storage using data collected from permanent forest inventory plots in the northeastern United States by the Forest Inventory and Analysis program of the USDA Forest Service. Quality assurance data collected from blind remeasurement audits were used to quantify error in diameter measurements, hollowness of logs, species identification, and decay class determination. Uncertainty estimates for density, collapse ratio, and carbon concentration were taken from the literature. Estimates of individual sources of uncertainty were combined using Monte Carlo methods. Volume estimates were more reliable than carbon storage, with an average 95% confidence interval of 15.9 m3/ha across the 79 plots evaluated, which was less than the mean of 31.2 m3/ha. Estimates of carbon storage (and mass) were more uncertain, due to poorly constrained estimates of the density of wood. For carbon storage, the average 95% confidence interval was 11.1 Mg C/ha, which was larger than the mean of 4.6 Mg C/ha. Accounting for the collapse of dead wood as it decomposes would improve estimates of both volume and carbon storage. On the other hand, our analyses suggest that consideration of the hollowness of downed coarse woody debris pieces could be eliminated in this region, with little effect. This study demonstrates how uncertainty analysis can be used to quantify confidence in estimates and to help identify where best to allocate resources to improve monitoring designs.

Beschreibung: Abstract The economic feasibility of carbon dioxide (CO2) enhanced oil recovery (EOR) to offset CO2 capture costs from a coal‐fired power plant are evaluated for 36 source‐sink scenarios in Ohio; one of the top ten states for fossil‐fuel use and CO2 emissions in the United States. Six capture scenarios are examined for a representative 550 megawatt (MW) coal‐fired power plant, and three CO2‐EOR injection scenarios are evaluated for both East Canton oil field and Gore consolidated oil field. The potential costs and credits associated with CO2 storage related tax incentives are also considered. Power plant capture performance and costs integrated with field‐scale CO2‐EOR techno‐economics suggest that there are potentially feasible scenarios for capture, transport, and CO2‐EOR storage of 25%, 50%, and 90% of CO2 emissions, respectively, from a 550 MW power plant. Economically feasible outcomes exhibiting net present values of $2191, $1380, and $1940 million are estimated for the 25%, 50%, and 90% capture scenarios, respectively. On average, the 45Q tax credit for CO2 storage affords a $3–$7 per barrel decrease in the minimum oil price required to break‐even on the project. In all source‐sink scenarios qualifying as feasible, the CO2 capture costs incurred by the power plant are offset by revenue from CO2‐EOR and are not passed on to ratepayers during the 30‐year analysis time frame. The most economical outcome for supporting a commercial carbon capture, utilization, and storage project in Ohio is also identified, and the potential impact of CO2‐EOR operational strategy on source‐sink feasibility is discussed. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Population persistence in the marine environment is driven by patterns of ocean circulation, larval dispersal, ecological interactions, and demographic rates. For habitat forming organisms in particular, understanding the relationship between larval connectivity and meta‐population dynamics aids in planning for marine spatial management. Here, we estimate networks of connectivity between fringing coral reefs in the North West Shelf of Australia by combining a particle tracking model based on shelf circulation with models of sub‐population dynamics of individual reefs. Coral cover data were used as a proxy for overall habitat quality, which can change as a result of natural processes, human‐driven impacts, and management initiatives. We obtain three major results of conservation significance. First, the dynamics of the ecological network result from the interplay between network connectivity and ecological processes on individual reefs. The maximum coral cover a zone can sustain imposes a significant non‐linearity on the role an individual reef plays within the dynamics of the network, and thus on the impact of conservation interventions on specific reefs. Second, the role of an individual reef within these network dynamics changes considerably depending on the overall state of the system: a reef’s role in sustaining the system’s state can be different from the same reef’s role in helping the system recover following major disturbance. Third, patterns of network connectivity change significantly as a function of yearly shelf circulation trends, and non‐linearity in network dynamics make mean connectivity a poor representation of yearly variations. From a management perspective, the priority list of reefs that are targets for management interventions depends crucially on what type of stressors (system‐wide vs localised) need addressing. This choice also depends not only on the ultimate purpose of management, but also on future oceanographic, climate change and development scenarios that will determine the network connectivity and habitat quality.

Beschreibung: Abstract In the Anthropocene, marine ecosystems are rapidly shifting to new ecological states. Achieving effective conservation of marine biodiversity has become a fast‐moving target because of both global climate change and continuous shifts in marine policies. How prepared are we to deal with this crisis? We examined EU Member States Programs of Measures designed for the implementation of EU marine policies, as well as recent European Marine Spatial Plans, and discovered that climate change is rarely considered operationally. Further, our analysis revealed that monitoring programs in marine protected areas are often insufficient to clearly distinguish between impacts of local and global stressors. Finally, we suggest that while the novel global Blue Growth approach may jeopardize previous marine conservation efforts, it can also provide conservation opportunities. Adaptive management is the way forward (e.g. preserving ecosystem functions in climate change hotspots, and identifying and targeting climate refugia areas for protection) using Marine Spatial Planning as a framework for action, especially given the push for Blue Growth.

Beschreibung: Abstract Quantifying the role of biophysical and anthropogenic drivers of coral reef ecosystem processes can inform management strategies that aim to maintain or restore ecosystem structure and productivity. However, few studies have examined the combined effects of multiple drivers, partitioned their impacts, or established threshold values that may trigger shifts in benthic cover. Inshore fringing reefs of the Great Barrier Reef Marine Park (GBRMP) occur in high‐sediment, high‐nutrient environments and are under increasing pressure from multiple acute and chronic stressors. Despite world‐leading management, including networks of no‐take marine reserves, relative declines in hard coral cover of 40‐50% have occurred in recent years, with localized but persistent shifts from coral to macroalgal dominance on some reefs. Here we use boosted regression tree analyses to test the relative importance of multiple biophysical drivers on coral and macroalgal cover using a long‐term (12‐18 year) dataset collected from reefs at four island groups. Coral and macroalgal cover were negatively correlated at all island groups, and particularly when macroalgal cover was above 20%. Although reefs at each island group had different disturbance‐and‐recovery histories, degree heating weeks (DHW) and routine wave exposure consistently emerged as common drivers of coral and macroalgal cover. In addition, different combinations of sea surface temperature, nutrient and turbidity parameters, exposure to high‐turbidity (primary) floodwater, depth, grazing fish density, farming damselfish density and zoning management variously contributed to coral and macroalgal cover at each island group. Clear threshold values were apparent for multiple drivers including wave exposure, depth and degree heating weeks for coral cover, and depth, degree heating weeks, chlorophyll‐a and cyclone exposure for macroalgal cover, however all threshold values were variable among island groups. Our findings demonstrate that inshore coral reef communities are typically structured by broad‐scale climatic perturbations, superimposed upon unique sets of local‐scale drivers. Although rapidly escalating climate change impacts are the largest threat to coral reefs of the GBRMP and globally, our findings suggest that proactive management actions that effectively reduce chronic stressors at local scales should contribute to improved reef resistance and recovery potential following acute climatic disturbances.

Beschreibung: Abstract A major challenge in ecology and environmental management is linking changes in community composition to ecosystem functions. We developed the network analysis of traits (NAT) to show changes in community network structure based on the changes in the composition and connectivity between clusters of species that share traits that imply shifts in functional diversity. We tested the application of NAT on a 113 species found on an intertidal sandflat that was subject to experimental nitrogen addition (control (0g Nm‐2), medium (150g Nm‐2) and high (600g Nm‐2) N treatments). This allowed us to directly link mechanistic changes in community composition and function with the trait‐space network patterns revealed by NAT. We demonstrate that under medium (150g Nm‐2) N treatment, functional diversity remained consistent, whereas increasing disturbance to high (600g Nm‐2) N treatment affected the species–trait network structure and caused merging of functional clusters implying a loss of functional trait diversity.

Beschreibung: Abstract A dynamically coupled mass, momentum, and heat transfer model was developed, which demonstrated the unstable behavior of CO2 movement inside porous sediment during high pressure injection and its transformation into solid hydrates. The presented mathematical model was solved using the implicit finite difference method, and through ordering the set of model equations, a complex integrated methodology could be established to analyze the CO2 hydrate nucleation procedure within P‐T equilibrium conditions. The results showed that the intrinsic permeability factor of the porous sediment had great influence on the pressure distribution. At 10−13 m2 intrinsic permeability, the formation pressure distribution became stable at an early stage of the hydrate growth process and remained stable afterwards. The overall hydrate covered length was 320 m due to the massive hydrate growth rate. When intrinsic permeability was reduced to 10−14 m2, it showed delay in pressure distribution and the overall hydrate covered length shifts to up to 310 m due to the delay in pressure distribution. Whereas at a 10−15 m2 intrinsic permeability factor, there was significant delay in pressure distribution so the injection pressure was not fully distributed even after 30 days of the induction process, which squeezed the hydrate covered length to 130 m. This pressure distribution had direct correlation with other parameter variations during the hydrate growth process, such as temperature distribution, hydrate growth rate, CO2 velocity, CO2 density, CO2 and H2O saturation, CO2 permeability, and interface boundary movement speed. Hence, the pressure distribution inside hydrate‐bearing sediment is the most dominant factor to enhance CO2 storage capacity but it does not give satisfactory results in extended formations. © 2019 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Secondary forests are a prominent component of tropical landscapes, and they constitute a major atmospheric carbon sink. Rates of carbon accumulation are usually inferred from chronosequence studies, but direct estimates of carbon accumulation based on long‐term monitoring of stands are rarely reported. Recent compilations on secondary forest carbon accumulation in the Neotropics are heavily biased geographically as they do not include estimates from the Guiana Shield. We analysed the temporal trajectory of aboveground carbon accumulation and floristic composition at one 25‐ha secondary forest site in French Guiana. The site was clearcut in 1976, abandoned thereafter, and one large plot (6.25 ha) has been monitored continuously since. We used Bayesian modelling to assimilate inventory data and simulate the long‐term carbon accumulation trajectory. Canopy change was monitored using two aerial lidar surveys conducted in 2009 and 2017. We compared the dynamics of this site with that of a surrounding old‐growth forest. Finally, we compared our results with that from secondary forests in Costa Rica, which is one of the rare long‐term monitoring programs reaching a duration comparable to our study. Twenty years after abandonment, aboveground carbon stock was 64.2 [95% credibility interval: 46.4;89.0] MgC/ha, and this stock increased to 101.3 [78.7;128.5] MgC/ha twenty years later. The time to accumulate half of the mean aboveground carbon stored in the nearby old‐growth forest (185.6 [155.9;200.2] MgC/ha) was estimated at 35.0 [20.9;55.9] years. During the first 40 years, the contribution of the long‐lived pioneer species Xylopia nitida, Goupia glabra and Laetia procera to the aboveground carbon stock increased continuously. Secondary forest mean‐canopy height measured by lidar increased by 1.14 m in eight years, a canopy‐height increase consistent with an aboveground carbon accumulation of 7.1 MgC/ha (or 0.89 MgC/ha/yr) during this period. Long‐term AGC accumulation rate in Costa Rica was almost twice as fast as at our site in French Guiana. This may reflect higher fertility of Central American forest communities or a better adaptation of the forest tree community to intense and frequent disturbances. This finding may have important consequences for scaling‐up carbon uptake estimates to continental scales.

Beschreibung: Abstract Forests globally are subject to disturbances such as logging and fire that create complex temporal variation in spatial patterns of forest cover and stand age. However, investigations that quantify temporal changes in biodiversity in response to multiple forms of disturbance in space and time are relatively uncommon. Over a 10‐year period, we investigated the response of bird species to spatio‐temporal changes in forest cover associated with logging and wildfire in the Mountain Ash (Eucalyptus regnans) forests of south‐eastern Australia. Specifically, we examined how bird occurrence changed with shifts in the proportion of area burnt or logged in a 4.5km radius surrounding our 88 long‐term field survey sites, each measuring 1 ha in size. Overall species richness was greatest in older forest patches, but declined as the amount of fire around each site increased. At the individual species level, 31 of the 37 bird species we modeled exhibited a negative response to the amount of fire in the surrounding landscape, while one species responded positively to fire. Only nine species exhibited signs of recovery in the six years of surveys following the fire. Five species were more likely to be detected as the proportion of logged forest surrounding a site increased, suggesting a possible “concentration effect” with displaced birds moving into unlogged areas following harvesting of adjacent areas. We also identified relationships between the coefficients of life history attributes and spatio‐temporal changes in forest cover and stand age. Large‐bodied birds and migratory species were associated with landscapes subject to large amounts of fire in 2009. There were associations between old growth stands and small‐bodied bird species and species that were not insectivores. Our study shows that birds in Mountain Ash forests are strongly associated with old growth stands and exhibit complex, time‐dependent and species‐specific responses to landscape disturbance. Despite logging and fire both being high‐severity perturbations, no bird species exhibited similar responses to fire and logging in the landscape surrounding our sites. Thus, species responses to one kind of landscape‐scale disturbance are not readily predictable based on an understanding of the responses to another kind of (albeit superficially similar) disturbance.

Beschreibung: Abstract The practice of using green manure for ecological restoration has grown so significantly that there is a shortage of seeds for purchase on the market. Nonetheless, there is very little literature available demonstrating the effects and benefits commonly cited for green manure for addressing important environmental filters, as herbivorous and invasive grasses. Our objective is to determine which spatial sowing arrangement including green manure promotes the lowest rates of herbivory on native species and decreases cover by invasive grasses in ecological restoration. We experimentally tested three sowing configurations of green manure intercropping with native species: (T1) mixture of native and green manure species in the same row, (T2) alternating rows of green manure and native species, and (T3) rows of native species intercropped with a 2 m wide strip of green manure. We found that: (1) green manure species experience greater damage from herbivory than do native, average value ranging from 1,8 times higher values in green manure than natives in T1, 2,9 times in T2, until 2,7 times in T3; when sown in rows and in broader strips, green manure and native species attract more herbivorous insects than if they were sown together (muvuca); and, (2) When green manure and native species are planted mixed in the same row they produce greater soil cover, and thus limit invasion by undesired species. The use of green manure has been identified as an alternative method for overcoming the environmental filters of herbivory and invasive grasses in restoration areas. Considering the demand for information that supports the use of green manure for purposes of ecological restoration, the novel results of the present study fill a void and should prove to be of great interest to researchers and practitioners. In addition, the presented results provide information on efficient and low‐cost restoration techniques that are necessary for the activity to gain scale, enabling countries to meet the large restoration targets.

Beschreibung: Abstract Climate warming is contributing to increases in wildfire activity throughout the western U.S., leading to potentially long‐lasting shifts in vegetation. The response of forest ecosystems to wildfire is thus a crucial indicator of future vegetation trajectories, and these responses are contingent upon factors such as seed availability, interannual climate variability, average climate, and other components of the physical environment. To better understand variation in resilience to wildfire across vulnerable dry forests, we surveyed conifer seedling densities in 15 recent (1988‐2010) wildfires and characterized temporal variation in seed cone production and seedling establishment. We then predicted post‐fire seedling densities at a 30‐m resolution within each fire perimeter using downscaled climate data, monthly water balance models, and maps of surviving forest cover. Widespread ponderosa pine (Pinus ponderosa) seed cone production occurred at least twice following each fire surveyed, and pulses of conifer seedling establishment coincided with years of above‐average moisture availability. Ponderosa pine and Douglas‐fir (Pseudotsuga menziesii) seedling densities were higher on more mesic sites and adjacent to surviving trees, though there were also important interspecific differences, likely attributable to drought‐ and shade‐tolerance. We estimated that post‐fire seedling densities in 42% (for ponderosa pine) and 69% (for Douglas‐fir) of the total burned area were below the lowest reported historical tree densities in these forests. Spatial models demonstrated that an absence of mature conifers (particularly in the interior of large, high‐severity patches) limited seedling densities in many areas, but 30‐year average actual evapotranspiration and climatic water deficit limited densities on marginal sites. A better understanding of the limitations to post‐fire forest recovery will refine models of vegetation dynamics and will help to improve strategies of adaptation to a warming climate and shifting fire activity.

Beschreibung: Abstract Rising temperatures and more frequent and severe droughts are driving increases in tree mortality in forests around the globe. However, in many cases, the likely trajectories of forest recovery following drought‐related mortality are poorly understood. In many fire‐suppressed western U.S. forests, management is applied to reverse densification and restore natural forest structure and composition, but it is unclear how such management affects post‐mortality recovery. We addressed these uncertainties by examining forest stands that experienced mortality during the severe drought of 2012‐2016 in California, USA. We surveyed post‐drought vegetation along a gradient of overstory mortality severity in paired treated (mechanically thinned or prescribed‐burned) and untreated areas in the Sierra Nevada. Treatment substantially reduced tree density, particularly in smaller tree size classes, and these effects persisted through severe drought‐related overstory mortality. However, even in treated areas with severe mortality (〉 67% basal area mortality), the combined density of residual (surviving) trees (mean 44 trees ha‐1) and saplings (mean 189 saplings ha‐1) frequently (86% of plots) fell within or exceeded the natural range of variation (NRV) of tree density, suggesting little need for reforestation intervention to increase density. Residual tree densities in untreated high‐mortality plots were significantly higher (mean 192 trees ha‐1 and 506 saplings ha‐1), and 96% of these plots met or exceeded the NRV. Treatment disproportionately removed shade‐tolerant conifer species, while mortality in the drought event was concentrated in pines (Pinus ponderosa and P. lambertiana); as a consequence, the residual trees, saplings, and seedlings in treated areas, particularly those that had experienced moderate or high drought‐related mortality, were more heavily dominated by broadleaf (“hardwood”) trees (particularly Quercus kelloggii and Q. chrysolepis). In contrast, residual trees and regeneration in untreated stands were heavily dominated by shade‐tolerant conifer species (Abies concolor and Calocedrus decurrens), suggesting a need for future treatment. Because increased dominance of hardwoods brings benefits for plant and animal diversity and stand resilience, the ecological advantages of mechanical thinning and prescribed‐fire treatments may, depending on the management perspective, extend even to stands that ultimately experience high drought‐related mortality following treatment.

Beschreibung: Abstract Species distribution models can predict the suitable climatic range of a potential biological control agent (BCA), but they provide little information on the BCA's potential impact. To predict high population build‐up, a pre‐requisite of biocontrol impact, studies are needed which assess the effect of environmental factors on vital rates of a BCA across the environmental gradient of the BCA's suitable habitats, especially for the region where the BCA is considered for field release. We extended a published species distribution model with climate‐dependent vital rates of Ophraella communa, a recently and accidentally introduced potential BCA of common ragweed, Ambrosia artemisiifolia in Europe. In field and laboratory experiments, we collected data on climate‐dependent parameters assumed to be the most relevant for the population build‐up of O. communa, i.e., temperature driving the number of generations per year and relative humidity (RH) determining egg hatching success. We found that O. communa concluded one generation in 334 cumulative degree days, and that egg hatching success strongly decreased from 〉80% to 〈20% when RH drops from 55% to 45% during the day. We used these values to spatially explicitly project population densities across the European range suitable for both A. artemisiifolia and the beetle and found that the present distribution of the beetle in Europe is within the range with the highest projected population growth. The highest population density of O. communa was predicted for northern Italy and parts of western Russia and western Georgia. Field observations of high impact on A. artemisiifolia with records of 80% aerial pollen reduction in the Milano area since the establishment of O. communa are in line with these predictions. The relative importance of temperature and RH on the population density of O. communa varies considerably across its suitable range in Europe. We propose that the combined statistical and mechanistic approach outlined in this paper helps to more accurately predict the potential impact of a weed BCA than a species distribution model alone. Identifying the factors limiting the population build‐up of a BCA across the suitable range allows implementation of more targeted release and management strategies to optimize biocontrol efficacy.

Beschreibung: Abstract As a water‐less fracturing mining technology, supercritical CO2 fracturing has attracted increasing attention in the mining industry. Based on detailed analysis of CO2 phase behavior in the whole process of supercritical CO2 fracturing, the whole cycle of supercritical CO2 fracturing was divided into the supercritical CO2 fracturing stage and the CO2 phase transition–induced fracturing stage, and according to the characteristics of each fracturing stage, the fracturing mechanism of supercritical CO2 was analyzed in stages, and the roles of the two stages in the life cycle of the entire supercritical CO2 fracturing process were obtained. Through the laboratory test of supercritical CO2 fracturing coal mass, the pressure–time curves during the whole process of supercritical CO2 fluid fracturing were analyzed, and the rationality and correctness of the supercritical CO2 fracturing staged analysis method proposed in this paper were verified. Based on the energy conservation theory and the state function equation of classical thermodynamics, the burst energy of the CO2 phase transition–induced fracturing stage was estimated. By comparing the trinitrotoluene equivalent of phase‐transition energy with the trinitrotoluene amount of explosive explosion, it was proved that the CO2 phase transition–induced fracturing stage was not negligible. The research results of this paper are of considerable significance for the full understanding of the supercritical CO2 fracturing mechanism. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract CO2 capture and storage (CCS) can be an important feature of a decarbonization strategy involving electricity generation. According to the recently revised Section 45Q tax credits, said credits will be provided for implementing CCS, which is motivating some United States (US) electricity generation companies to revisit their business strategies for CCS. This paper discusses alternative business models being considered by companies for undertaking CCS, including providing a ‘template’ for evaluating the cost‐effectiveness of CCS with Section 45Q tax credits and storage in saline reservoirs. Using stylized illustrative examples, the paper indicates how use of Section 45Q tax credits should be expected to change dispatch at an electricity generating unit. For situations similar to the examples, the paper suggests that Section 45Q tax credits may need to be modified to achieve its intended impact. Modifications can include extending the time period of tax credit availability beyond the current 12 years. In addition, continued R&D investments in CCS and specific support for first‐of‐a‐kind CCS demonstrations would be valuable complements for the deployment of the Section 45Q tax credit. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Levine et al. (2019; LE hereafter) claim our landscape‐scale method for reconstructing historical forests fails, based on updated modern tests in six disjunct small plots, half located in highly altered forests, but here we show our method works even at these inadequate sites. LE is a correction of Levine et al. (2017; LE2017 hereafter). In Baker and Williams (2018; B&W hereafter), we showed that LE2017 did not correctly test our method in these same small plots.

Beschreibung: Abstract Digging animals may alter many characteristics of their environment as they disrupt and modify the ground’s surface by creating foraging pits or burrows. Extensive disturbance to the soil and litter layer changes litter distribution and availability, potentially altering fuel loads. In many landscapes, including peri‐urban areas, fire management to reduce fuel loads is complex and challenging. The reintroduction of previously common digging animals, many of which are now threatened, may have the added benefit of reducing fuel loads. We experimentally examined how the reintroduction of a marsupial bandicoot, quenda (Isoodon fusciventer), altered surface fuel loads in an urban bush reserve in Perth, Western Australia. Foraging activities of quenda (where they dig for subterranean food) were substantial throughout the reserve, creating a visibly patchy distribution in surface litter. Further, in open plots where quenda had access, compared to fenced plots where quenda were excluded, quenda foraging significantly reduced litter cover and litter depth. Similarly, estimated surface fuel loads were nearly halved in open plots where quenda foraged compared to fenced plots where quenda were absent (3.6 c.f. 6.4 tonnes ha‐1). Fire behaviour modelling, using the estimated surface fuel loads, indicated the predicted rate of spread of fire were significantly lower for open plots where quenda foraged compared to fenced plots under both low (29.2 c.f. 51.4 m hr‐1; total fuels) and high (74.3 c.f. 130.4 m hr‐1; total fuels) fire conditions. Although many environments require fire, including the bushland where this study occurred, fire management can be a considerable challenge in many landscapes, including urban bushland reserves which are usually small and close to human infrastructure. The reintroduction of previously common digging species may have potential value as a complimentary tool for reducing fuel loads, and potentially, fire risk.

Beschreibung: Abstract Exotic invasive plants threaten ecosystem integrity, and their success depends on a combination of abiotic factors, disturbances, and interactions with existing communities. In dryland ecosystems, soil biocrusts (communities of lichens, bryophytes and microorganisms) can limit favorable microsites needed for invasive species establishment, but the relative importance of biocrusts for landscape‐scale invasion patterns remains poorly understood. We examine effects of livestock grazing in habitats at high risk for invasion to test the hypothesis that disturbance indirectly favors exotic annual grasses by reducing biocrust cover. We present some of the first evidence that biocrusts increase site resistance to invasion at a landscape scale and mediate the effects of disturbance. Biocrust species richness, which is reduced by livestock grazing, also appears to promote native perennial grasses. Short mosses, as a functional group, appeared to be particularly valuable for preventing invasion by exotic annual grasses. Our study suggests that maintaining biocrust communities with high cover, species richness, and cover of short mosses can increase resistance to invasion. These results highlight the potential of soil surface communities to mediate invasion dynamics and suggest promising avenues for restoration in dryland ecosystems.

Beschreibung: Abstract The natural range of variation (NRV) is an important reference for ecosystem management, but has been scarcely quantified for forest landscapes driven by infrequent, severe disturbances. Extreme events such as large, stand‐replacing wildfires at multi‐century intervals are typical for these regimes; however, data on their characteristics are inherently scarce, and, for land management, these events are commonly considered too large and unpredictable to integrate into planning efforts (the proverbial ‘Black Swan’). Here, we estimate the NRV of late‐seral (mature/old‐growth) and early‐seral (post‐disturbance, pre‐canopy‐closure) conditions in a forest landscape driven by episodic, large stand‐replacing wildfires: the Western Cascade Range of Washington, USA (2.7 million ha). These two seral stages are focal points for conservation and restoration objectives in many regions. Using a state‐and‐transition simulation approach incorporating uncertainty, we assess the degree to which NRV estimates differ under a broad range of literature‐derived inputs regarding: a) overall fire rotations, and b) how fire area is distributed through time – as relatively frequent smaller events (less episodic), or fewer but larger events (more episodic). All combinations of literature‐derived fire rotations and temporal distributions (i.e. ‘scenarios’) indicate that the largest wildfire events (or episodes) burned up to 105‐106 hectares. Under most scenarios, wildfire dynamics produced 5th‐95th percentile ranges for late‐seral forests of ~47‐90% of the region (median 70%), with structurally complex early‐seral conditions composing ~1‐30% (median 6%). Fire rotation was the main determinant of NRV, but temporal distribution was also important, with more episodic (temporally clustered) fire yielding wider NRV. In smaller landscapes (20,000 ha; typical of conservation reserves and management districts), ranges were 0‐100% because fires commonly exceeded the landscape size. Current conditions are outside the estimated NRV, with the majority of the region instead covered by dense mid‐seral forests (i.e. a regional landscape with no historical analog). Broad consistency in NRV estimates among widely varied fire regime parameters suggests these ranges are likely relevant even under changing climatic conditions, both historical and future. These results indicate management‐relevant NRV estimates can be derived for seral stages of interest in extreme‐event landscapes, even when incorporating inherent uncertainties in disturbance regimes.

Beschreibung: Abstract In subalpine forests of the western United States that historically experienced infrequent, high‐severity fire, whether fire management can shape 21st‐century fire regimes and forest dynamics to meet natural resource objectives is not known. Managed wildfire use (i.e., allowing lightning‐ignited fires to burn when risk is low instead of suppressing them) is one approach for maintaining natural fire regimes and fostering mosaics of forest structure, stand age, and tree‐species composition, while protecting people and property. However, little guidance exists for where and when this strategy may be effective with climate change. We simulated most of the contiguous forest in Grand Teton National Park, WY to ask: (1) How would subalpine fires and forest structure be different if fires had not been suppressed during the last three decades? (2) What is the relative influence of climate change versus fire management strategy on future fire and forests? We contrasted fire and forests from 1989‐2098 under two fire management scenarios (managed wildfire use and fire suppression), two general circulation models (CNRM‐CM5 and GFDL‐ESM2M), and two representative concentration pathways (8.5 and 4.5). We found little difference between management scenarios in the number, size, or severity of fires during the last three decades. With 21st‐century warming, fire activity increased rapidly, particularly after 2050, and followed nearly identical trajectories in both management scenarios. Area burned per year between 2018‐2099 was 1,700% greater than in the last three decades (1989‐2017). Large areas of forest were abruptly lost; only 65% of the original 40,178 ha of forest remained by 2098. However, forests stayed connected and fuels were abundant enough to support profound increases in burning through this century. Our results indicate that strategies emphasizing managed wildfire use, rather than suppression, will not alter climate‐induced changes to fire and forests in subalpine landscapes of western North America. This suggests that managers may continue to have flexibility to strategically suppress subalpine fires without concern for long‐term consequences, in distinct contrast with dry conifer forests of the Rocky Mountains and mixed conifer forest of California where maintaining low fuel loads is essential for sustaining frequent, low‐severity surface fire regimes.

Beschreibung: Ecological Applications, EarlyView.

Beschreibung: Abstract Habitat loss and fragmentation greatly affect biological diversity. Actions to counteract their negative effects include increasing the quality, amount and connectivity of semi‐natural habitats at the landscape scale. However, much of the scientific evidence underpinning landscape restoration comes from studies of habitat loss and fragmentation, and it is unclear whether the ecological principles derived from habitat removal investigations are applicable to habitat creation. In addition, the relative importance of local‐ (e.g. improving habitat quality) vs. landscape‐level (e.g. increasing habitat connectivity) actions to restore species is largely unknown, partly because studying species responses over sufficiently large spatial and temporal scales is challenging. We studied small mammal responses to large scale woodland creation spanning 150 years, and assessed the influence of local‐ and landscape‐level characteristics on three small mammal species of varying woodland affinity. Woodland specialists, generalists and grassland specialists were present in woodlands across a range of ages from 10 to 160 years, demonstrating that these species can quickly colonize newly created woodlands. However, we found evidence that woodlands become gradually better over time for some species. The responses of individual species corresponded to their habitat specificity. A grassland specialist (Microtus agrestis) was influenced only by landscape attributes; a woodland generalist (Apodemus sylvaticus) and specialist (Myodes glareolus) were primarily influenced by local habitat attributes, and partially by landscape characteristics. At the local scale, high structural heterogeneity, large amounts of deadwood and a relatively open understory positively influenced woodland species (both generalists and specialists); livestock grazing had strong negative effects on woodland species abundance. Actions to enhance habitat quality at the patch scale focusing on these attributes would benefit these species. Woodland creation in agricultural landscapes is also likely to benefit larger mammals and birds of prey feeding on small mammals and increase ecosystem processes such as seed dispersal.

Beschreibung: Abstract Growing interest in offshore geologic carbon sequestration (GCS) motivates evaluation of the consequences of subsea CO2 well blowouts. We have simulated a hypothetical major CO2 well blowout in shallow water of the Texas Gulf Coast. We use a coupled reservoir‐well model (T2Well) to simulate the subsea blowout flow rate for input to an integral model (TAMOC) for modeling CO2 transport in the water column. Bubble sizes are estimated for the blowout scenario for input to TAMOC. Results suggest that a major CO2 blowout in ≥50 m of water will be almost entirely attenuated by the water column due to CO2 dissolution into seawater during upward rise. In contrast, the same blowout in 10 m of water will hardly be attenuated at all. Results also show that the size of the orifice of the leak strongly controls the CO2 blowout rate. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Surrogate species are commonly used in conservation science due to the fact that it is not feasible to measure and manage each component of biodiversity independently; yet, there is much debate about their efficacy. We use long‐term monitoring data from six national park units in northern California and southern Oregon to test the focal species approach, wherein a suite of species is selected whose habitat requirements collectively encompass those of co‐occurring species. Specifically, we examine how well existing Partners in Flight (PIF) habitat‐based focal species lists and empirically derived focal species lists represent vegetation and three avian assemblages of interest: the entire assemblage, species of concern, and common species in steep decline. Existing PIF focal species lists were significantly correlated with the three alternative matrices of avian assemblages and vegetation, but not all parks and alternate matrices performed with equal correlative strength and/or significance. For example, existing PIF focal species lists were significantly correlated to the entire assemblage at five of the six parks and had ecologically meaningful correlations (〉0.70) at four. However, PIF focal species list correlations with park specific species of concern and common species in steep declined varied widely, with correlations between 0.040–0.943 and 0.210–0.556, respectively. Averaged across park units the empirical focal species lists developed to represent both vegetation metrics and species of concern improved correlation with all alternative matrices of avian assemblages and vegetation metrics. We found that the focal species approach generally represented the entire avian community, but did not adequately represent suites of species of concern or common species in decline. Empirical testing is a critical step in validating or refining suites of focal species at management relevant scales, and in some instances, a more refined focal species list may increase overall utility of the surrogate species approach.

Beschreibung: Abstract Novel Mn‐doped CaO was prepared by the combustion method. The CO2 capture performance of Mn‐doped CaO, carbonated in the presence of steam and under severe calcination conditions (950°C and 70% CO2/30% N2) during calcium looping cycles, was investigated in a dual fixed‐bed reactor. The intercoupling effects of Mn and steam on CO2 capture by CaO were also studied. Doping of Mn in CaO by the combustion method greatly improved the CO2 capture capacity of CaO. The carbonation conversions of Mn‐doped CaO increased with increasing steam concentration from 0 to 15%. When the molar ratio of Mn/Ca was 0.75 : 100, Mn‐doped CaO achieved the highest CO2 capture capacity. Under severe calcination conditions, the carbonation conversion of Mn‐doped CaO, where the molar ratio of Mn to Ca = 0.75 : 100 in the presence of 15% steam, was about 0.4 after ten cycles (carbonation for 5 min at 650°C under 15% CO2/15% steam/N2), which was 4.38 times as high as that of the original CaO in the absence of steam. The cyclic CO2 capture capacities of CaO were improved by Mn and steam. Synergistic enhancement effects of Mn and steam on the CO2 capture capacities of CaO were also found. The effect of steam on the carbonation conversion of Mn‐doped CaO was stronger than that of the original CaO. Mn in the presence of steam showed a more positive effect on CO2 capture by CaO. X‐ray photoelectron spectroscopy analysis showed that doping of Mn in CaO enhanced the transport of electrons in the carbonation of CaO, which helped to increase the carbonation rate. When steam was present in the carbonation, Mn‐doped CaO possessed a more porous structure and smaller CaO grains than the original CaO during the cycles. Simulation calculations using periodic density functional theory (DFT) showed that CO2 molecules were easier to absorb on CaO owing to the doping of Mn and the presence of steam. The synergistic enhancement effects of Mn and steam on CO2 captured the performance of CaO. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Plants often form the basis of conservation planning and management. The effectiveness of plant diversity as a surrogate for arthropod diversity was assessed in natural areas in the Kogelberg Biosphere Reserve, a floral endemism hotspot in the Cape Floristic Region (CFR), South Africa. Arthropods and plants were sampled across 30 topographically heterogeneous sites in a spatially nested design. The relationship between plants and arthropods were quantified in terms of species richness, assemblage variation, and assemblage turnover. The influence of arthropod trophic groups, habitat association, and spatial scale were also explored. Generalized dissimilarity modelling was used to investigate differential influence of explanatory groups (geology, disturbance, local site characteristics, refuge, mesoclimate, terrain) on arthropod and plant turnover. Congruence in assemblage variation was restricted to local scales, and only present between plants and those arthropods associated with the foliar component of the habitat. Weak congruence in species turnover was due to differences in the relative importance of explanatory groups, with different variables within each explanatory group being important, and similar variables predicting different turnover patterns. For both groups, variables related to geology and fire history were important for assemblage turnover. These variables are already incorporated in conservation planning and management for plant diversity across the CFR. Overall plant diversity was a weak surrogate for the arthropod groups included in this study, suggesting that as an alternative, environmental surrogates for arthropod diversity perform better. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Ecologists are pressed to understand how climate constrains the timings of annual biological events (phenology). Climate influences on phenology are likely significant in estuarine watersheds because many watersheds provide seasonal fish nurseries where juvenile presence is synched with favorable conditions. While ecologists have long recognized that estuaries are generally important to juvenile fish, we incompletely understand the specific ecosystem dynamics that contribute to their nursery habitat value, limiting our ability to identify and protect vital habitat components. Here we examined the annual timing of juvenile coldwater fish migrating through a seasonally warm, hydrologically managed watershed. Our goal was to (1) understand how climate constrained the seasonal timing of water conditions necessary for juvenile fish to use nursery habitats and (2) inform management decisions about (a) mitigating climate‐mediated stress on nursery habitat function and (b) conserving heat‐constrained species in warming environments. Cool, wet winters deposited snow and cold water into mountains and reservoirs, which kept the lower watershed adequately cool for juveniles through the spring despite the region approaching its hot, dry summers. For every 1 °C waters in April were colder, the juvenile fish population (1) inhabited the watershed 4 – 7 days longer and (2) entered marine waters, where survival is size selective, at maximum sizes 2.1 mm larger. Climate therefore appeared to constrain the nursery functions of this system by determining seasonal windows of tolerable rearing conditions, and cold water appeared to be a vital ecosystem component that promoted juvenile rearing. Fish in this system inhabit the southernmost extent of their range and already rear during the coolest part of the year, suggesting that a warming climate will truncate rather than shift their annual presence. Our findings are concerning for coldwater diadromous species in general because warming climates may constrain watershed use and diminish viability of life histories (e.g., late springtime rearing) and associated portfolio benefits over the long term. Lower watershed nurseries for coldwater fish in warming climates may be enhanced through allocating coldwater reservoir releases to prolong juvenile rearing periods downstream or restorations that facilitate colder conditions. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Plantation forestry, in which trees are grown as a crop, must maintain wood production over repeated harvest cycles (rotations) to meet global wood demands on a limited land area. We analyze 33 years of Landsat observations across the world's most productive forestry system, Eucalyptus plantations in southeastern Brazil, to assess long‐term regional trends in wood production. We apply a simple algorithm to time series of the vegetation index NIRv in thousands of Eucalyptus stands to detect the starts and ends of rotations. We then estimate wood production in each identified stand and rotation, based on a statistical relationship between NIRv trajectories and inventory data from three plantation companies. We also compare Eucalyptus NIRv with that of surrounding native vegetation to assess the relative influence of management and environment on plantation productivity trends. Across more than 3500 stands with three complete rotations between 1984 and 2016, modeled wood volume decreased significantly between the first and second rotation, but recovered at least partially in the third; mean wood volumes for the three rotations were 262, 228, and 247 m3 ha−1. This nonlinear trend reflects intensifying plantation management, as rotation length decreased by an average of 15% (decreasing wood volume per rotation) and NIRv proxies of tree growth rates increased (increasing volume) between the first and third rotation. However, NIRv also increased significantly over time in unmanaged vegetation around the plantations, suggesting that environmental trends affecting all vegetation also contribute to sustaining wood production. Management inputs will likely continue to be important for maintaining wood production in future harvests. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract The unprecedented global biodiversity loss has massive implications for the capacity of ecosystems to maintain functions critical to human well‐being, urgently calling for rapid, scalable, and reproducible strategies for biodiversity monitoring, particularly in threatened ecosystems with difficult field access such as wetlands. Remote sensing indicators of spectral variability and greenness may predict the diversity of plant communities based on their optical diversity; however, most evidence is based on narrowband spectral data or terrestrial ecosystems. We investigate how spectral greenness and heterogeneity from publicly available broadband multi‐spectral Landsat satellite imagery explain variation in vegetation diversity across different wetland types, ecoregions, and disturbance levels using 1,138 sites surveyed by U.S EPA's National Wetland Condition Assessment. We found positive correlations of plant species richness and diversity with indicators of annual maximum spectral greenness and its spatial heterogeneity, explaining up to 43% variation within the global sample, 48% within wetland types or ecoregions, and up to 61% with abiotic covariates. The combined effect of spectral greenness and heterogeneity was stronger than the best‐performing model using climatic, topographic, and edaphic factors alone. When compared among major U.S. watersheds and individual states, the fit of diversity‐greenness models increased when more wetland types were included within the corresponding region's boundaries, up to 61% at the watershed and 77% at the state level, respectively, for diversity models and up to 73% and 80%, respectively, for richness models. Model outliers were characterized by a significantly greater diversity of non‐native species (p〈0.0001), suggesting that changes in model performance and greenness distributions could be used as indicators of shifts in plant community composition, particularly in tidal wetlands making the majority of outliers with significantly lower than predicted diversity. This study represents a first‐time national‐scale effort to use publicly available remote sensing, climatic, and topographic data to predict plant diversity in wetlands, which tend to be understudied compared to terrestrial ecosystems despite being among the most stressed ecosystems on Earth. Our study suggests that multi‐temporal broadband satellite imagery could provide a low‐cost assessment of regional and national wetland biodiversity for prioritization of conservation efforts and early detection of biodiversity loss. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Broad‐scale studies have improved our ability to make predictions about how freshwater biotic and abiotic properties will respond to changes in climate and land use intensification. Further, fine‐scaled studies of lakes, wetlands, or streams have documented the important role of hydrologic connections for understanding many freshwater biotic and abiotic processes. However, lakes, wetlands, and streams are typically studied in isolation of one another at both fine and broad‐scales. Therefore, it is not known whether these three freshwater types (lakes, wetlands, and streams) respond similarly to ecosystem and watershed drivers nor how they may respond to future global stresses. In this study, we asked: do lake, wetland, and stream biotic and abiotic properties respond to similar ecosystem and watershed drivers and have similar spatial structure at the national scale? We answered this question with three U.S. conterminous datasets of freshwater ecosystems. We used random forest (RF) analysis to quantify the multi‐scaled drivers related to variation in nutrients and biota in lakes, wetlands, and streams simultaneously; we used semivariogram analysis to quantify the spatial structure of biotic and abiotic properties and to infer possible mechanisms controlling the ecosystem properties of these freshwater types. We found that abiotic properties responded to similar drivers, had large ranges of spatial autocorrelation, and exhibited multi‐scale spatial structure, regardless of freshwater type. However, the dominant drivers of variation in biotic properties depended on freshwater type and had smaller ranges of spatial autocorrelation. Our study is the first to document that drivers and spatial structure differ more between biotic and abiotic variables than across freshwater types, suggesting that some properties of freshwater ecosystems may respond similarly to future global changes. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Migratory birds rely on a habitat network along their migration routes by temporarily occupying stopover sites between breeding and non‐breeding grounds. Removal or degradation of stopover sites in a network might impede movement, and thereby reduce migration success and survival. The extent to which the breakdown of migration networks, due to changes in land use, impacts the population sizes of migratory birds is poorly understood. We measured the functional connectivity of migration networks of waterfowl species that migrate over the East Asian‐Australasian Flyway from 1992‐2015. We analysed the relationship between changes in non‐breeding population sizes and changes in functional connectivity, while taking into account other commonly‐considered species traits, using a Phylogenetic Linear Mixed Model. We found that population sizes significantly declined with a reduction in the functional connectivity of migration networks; no other variables were important. We conclude that the current decrease in functional connectivity, due to habitat loss and degradation in migration networks, can negatively and crucially impact population sizes of migratory birds. Our findings provide new insights into the underlying mechanisms that affect population trends of migratory birds under environmental changes. Establishment of international agreements leading to the creation of systematic conservation networks associated with migratory species’ distributions and stopover sites may safeguard migratory bird populations. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Assessing the persistent impacts of fragmentation on above ground structure of tropical forests is essential to understanding the consequences of land use change for carbon storage and other ecosystem functions. We investigated the influence of edge distance and fragment size on canopy structure, aboveground woody biomass (AGB), and AGB turnover in the Biological Dynamics of Forest Fragments Project (BDFFP) in central Amazon, Brazil, after 22+ years of fragment isolation, by combining canopy variables collected with Portable Canopy profiling lidar and airborne laser scanning surveys with long‐term forest inventories. Forest height decreased by 30% at edges of large fragments (〉 10 ha) and interiors of small fragments (〈 3 ha). In larger fragments, canopy height was reduced up to 40 m from edges. Leaf area density profiles differed near edges: the density of understory vegetation was higher and midstory vegetation lower, consistent with canopy reorganization via increased regeneration of pioneers following post‐fragmentation mortality of large trees. However, canopy openness and leaf area index remained similar to control plots throughout fragments, while canopy spatial heterogeneity was generally lower at edges. AGB stocks and fluxes were positively related to canopy height and negatively related to spatial heterogeneity. Other forest structure variables typically used to assess the ecological impacts of fragmentation (basal area, density of individuals, and density of pioneer trees) were also related to lidar‐derived canopy surface variables. Canopy reorganization through the replacement of edge‐sensitive species by disturbance‐tolerant ones may have mitigated the biomass loss effects due to fragmentation observed in the earlier years of BDFFP. Lidar technology offered novel insights and observational scales for analysis of the ecological impacts of fragmentation on forest structure and function, specifically aboveground biomass storage. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Oil wells that intersect a potential CO2 storage zone in a depleted oil and gas field may provide leakage pathways. It is essential to estimate the field‐scale leakage risk associated with these wells. In this study, a risk‐based approach is used to estimate the risk of leakage. Existing reduced‐order models for well leakage are used to quantitatively estimate well leakage rates for cased‐cemented, cased‐uncemented, and open wellbores. For each existing well that intersects the storage zone, we introduce the well leakage index (WLI), which accounts for wellbore geometry, distance from the injection well, buffer layers between the storage zone and underground sources of drinking water, and the nature of storage zone boundary type. For an initial injection well location, the total site well leakage index (SWLI) is calculated, which is the summation of the WLI for all of the wells. Next, the injector location is varied areally and SWLI is calculated for a specified number of potential injector well locations in the storage zone area. Small values for the SWLI correspond to low well leakage potential, indicating where injection well locations can be considered. The developed criterion provides a means to systemically find the areas with highest and lowest well leakage potential for a storage zone. Due to the reduced order nature of the developed method, it should be a useful tool in the planning and execution phase of the CO2 geological sequestration process. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Geological carbon storage (GCS) refers to the technology of capturing man‐made carbon dioxide (CO2) emissions, typically from stationary power sources, and storing such emissions in deep underground reservoirs. GCS is an approach being explored globally as a defense mechanism against climate change projections, although it is not without its critics. An important focus has been recently placed on understanding the coupling between rock–fluid geochemical alterations and mechanical changes for CO2 storage schemes in saline aquifers. This article presents a review of the current state of knowledge regarding CO2‐induced geochemical reactions in subsurface reservoirs, and their potential impact on mechanical properties and microseismic events at CO2 storage sites. This review focuses, in particular, on the current state of the art in fluid–rock interactions within the GCS context. Key issues to be addressed include geochemical reactions and the alteration of transport and mechanical properties. Specific review topics include the swelling of clays, the prediction of dissolution and precipitation reaction rates, CO2‐induced changes in porosity and permeability, constitutive models of chemo–mechanical interactions in rock, and correlations between geochemical reactions and induced seismicity. The open questions in the field are emphasized, and new research needs are highlighted. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract An audit is not always something that an organisation looks forward to. Having procedures or expenditures critiqued by an independent body has the potential to be nerve‐wracking. But the scrutiny can often lead to better decisions for the future. In this article, GHGS&T's Muriel Cozier looks at the findings from the audit of the past 10 years of European Union's climate action. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Biodiversity has a close relationship with ecosystem functioning. For most biodiversity–ecosystem functioning studies, biodiversity has been linked to a single indicator variable of ecosystem functioning. However, there are generally multiple ecosystem processes contributing to ecosystem functioning and they differ in their dependence on biodiversity. Thus, the relationship between biodiversity and ecosystem functioning can be stronger when multiple rather than single ecosystem processes are considered. Using both mass‐balance and stable‐isotope approaches, we explored the effects of plant diversity on nitrogen (N) removal sustained by multiple N‐cycling processes in experimental microcosms simulating constructed wetlands, an ecosystem treating wastewater with high N loading. Four species were used to assemble different plant communities, ranging in richness from one to four species. The removal of N, indicated by low levels of total inorganic N concentration (TIN) present in the effluent, was considered as an integrated measure of ecosystem functioning, combining three constituent N‐cycling processes: plant uptake, denitrification and substrate adsorption. Our results showed that: (1) species richness had a positive effect on N removal, in particular, the four‐species mixture reduced effluent TIN to a lower level than any monoculture, however, polycultures (two‐, three‐ and four‐species mixtures) did not outperform the most‐efficient monoculture when each of the three constituent N‐cycling processes was considered by itself; (2) species identity had significant impacts on single processes. Communities with the species Coix lacryma‐jobi showed the greatest capacity for N uptake and communities with Phragmites australis had the highest denitrification rates; (3) isotope fractionation in the rhizosphere of Coix lacryma‐jobi was primarily due to microbial denitrification while multistep isotope fractionation was detected for Phragmites australis and Acorus calamus (indicating recycling of N), suggesting that species differed in the way they transformed N; (4) the enhanced N removal at high diversity may be due to mutualistic interactions among species belonging to different functional types. Our findings demonstrated that although plant species richness had negligible effects on individual N‐cycling processes, it enhanced the overall ecosystem functioning (N removal) when these processes were considered collectively. Our study thus contributes to improve the treatment efficiency of constructed wetlands through proper vegetation management. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Climate change and urban growth impact habitats, species, and ecosystem services. To buffer against global change, an established adaptation strategy is designing protected areas to increase representation and complementarity of biodiversity features. Uncertainty regarding the scale and magnitude of landscape change complicates reserve planning and exposes decision makers to risk of failing to meet conservation goals. Conservation planning tends to treat risk as an absolute measure, ignoring the context of the management problem and risk preferences of stakeholders. Application to conservation of risk management theory emphasizes diversification of portfolio of assets, with the goal of reducing the impact of system volatility on investment return. We use principles of Modern Portfolio Theory (MPT), which quantifies risk as the variance and correlation among assets, to formalize diversification as an explicit strategy for managing risk in climate‐driven reserve design. We extend MPT to specify a framework that evaluates multiple conservation objectives, allows decision makers to balance management benefits and risk when preferences are contested or unknown, and includes additional decision options such as parcel divestment when evaluating candidate reserve designs. We apply an efficient search algorithm that optimizes portfolio design for large conservation problems and a game theoretic approach to evaluate portfolio tradeoffs that satisfy decision makers with divergent benefit and risk tolerances, or when a single decision maker cannot resolve their own preferences. Evaluating several risk profiles for a case study in South Carolina, our results suggest that a reserve design may be somewhat robust to differences in risk attitude but that budgets will likely be important determinants of conservation planning strategies, particularly when divestment is considered a viable alternative. We identify a possible fiscal threshold where adequate resources allow protecting a sufficiently diverse portfolio of habitats such that the risk of failing to achieve conservation objectives is considerably lower. For a range of sea‐level rise projections, conversion of habitat to open water (14‐180%) and wetland loss (1‐7%) are unable to be compensated under the current protected network. In contrast, optimal reserve design outcomes are predicted to ameliorate expected losses relative to current and future habitat protected under the existing conservation estate. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Millions of farm ponds have been constructed in agricultural landscapes throughout the globe. These ponds are built to support a variety of functions, including erosion control, cattle grazing, and recreational fishing, but their role as breeding habitat for amphibians remains poorly understood. We addressed this knowledge gap by studying farm ponds in the eastern Great Plains of the United States, a pond‐dense region dominated by agriculture. We used field surveys and occupancy modeling to identify the important biophysical components of amphibian habitat and to assess the species‐specific effects of cattle and fish presence on breeding occupancy. We next used a chronosequence to determine whether pond renovation, which often occurs when ponds are about 40 years old, threatens the development of amphibian habitat. Nine amphibian species bred in the farm ponds that we surveyed, and the relationship between breeding occupancy and habitat variables varied by species. We found that the pH conditions associated with amphibian breeding occupancy were significantly more likely to occur in older ponds (〉 50 years old). Emergent vegetation cover was also associated with increased breeding probability and rarely reached high levels in newer ponds. Since the older ponds with suitable habitat are at an age where renovation is likely needed to restore their agricultural function, this habitat may be at risk. We suggest that conservation of amphibians in farm ponds in the United States will require adopting renovation and management practices that balance the multiple uses of these sites and maintain a mosaic of pond successional states. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Sequence SO2/CO2 capture technology will be more attractive as the control on secondary pollution is strengthened and the operating cost is decreased. The sulfation, pore, and fractal characteristics of a spent CaO‐based adsorbent are studied. The spent modified CaO/Ca12Al14O33 is used in this study. The effect of cyclic numbers in the calcium‐looping process on sulfation conversion and the pore characteristics of spent adsorbents is investigated. A model between the fractal dimension and the Brunner–Emmet–Teller (BET) specific surface area (SBET) of the spent CaO/Ca12Al14O33 is established. The sulfation reaction characteristic of spent adsorbents is also interpreted by the fractal mechanism. Results show that the sulfation conversions of spent CaO/Ca12Al14O33 are almost 10% higher than those of spent CaO at the same cyclic number. The sulfation reaction rate in the product layer diffusion‐controlled stage is much lower than that in the chemical reaction‐controlled stage. The spent CaO/Ca12Al14O33 adsorbents are mainly composed of meso‐ and macropores. The pore size distributions show that there are two peaks in the curves. The surface fractal dimension (D1) and the pore fractal dimension values of spent adsorbents show a trend that is similar to those of SBET and total pore volume, respectively. The relation between the D1 values of four different CaO‐based adsorbents and their SBET values is a quadratic function, and a higher D1 indicates an irregular surface of disordered fractals, which significantly affects the efficiency of the sulfation reaction. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract The global warming and change in climatic conditions due to rising concentration of CO2 in atmosphere are the most important challenges of 21st century. Catalytic conversion of CO2 to methanol will not only check global warming but also provide an alternative source of fuel. The phase purity of solid catalysts has a considerable influence on the desired product selectivity. Reduction temperature is one of the most important parameters responsible for catalyst phase formation. Herein, the effect of a range of reduction temperatures between 100 and 600°C on the phase composition of Pd–Ga bimetallic catalyst and CO2 hydrogenation to methanol activity was investigated. X‐ray diffraction (XRD) analysis revealed the formation of different phases at different reduction temperatures. The variation in catalyst structure was also analyzed using field emission scanning electron microscope‐energy dispersive X‐ray spectroscopy (FESEM‐EDS), Brunaue–Emmett–Teller, H2 chemisorption, and transmission electron microscopy techniques. The influence of reduction temperature, pressure (1–25 bar), H2/CO2 ratio (3–9), and reaction temperature (150–250°C) on methanol and CO selectivity from CO2 hydrogenation at atmospheric pressure was also studied. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract In the context of geologic carbon dioxide (CO2) sequestration, the storage effectiveness of a caprock–reservoir system is a function of the properties of both the caprock and reservoir – namely, the ability of the caprock to prevent upward leakage of CO2 (caprock sealing capability), the mechanical response of the reservoir and caprock (by evaluating in situ stress changes), and the extent and degree to which CO2 can be trapped over long periods of time. In this work, all three parameters were considered to evaluate the storage effectiveness of the Cambrian–Ordovician sequence of the Northern Appalachian Basin. We constructed a series of hydro‐mechanical models to investigate interactions between CO2 flow and geomechanical processes and to evaluate the three aspects of storage performance. Models were built to evaluate two scenarios: (1) single reservoirs with a single overlying caprock, and (2) systems comprising multiple reservoirs and multiple intermediate caprock units in addition to the primary (uppermost) caprock unit. The overall conclusion of the work is that focusing only on one aspect of storage effectiveness might not necessarily warrant long‐term CO2 storage. Results of the sensitivity analysis for the single caprock–reservoir system show that each storage effectiveness metric has its own control parameters. A comparison among three stacked caprock–reservoir systems in different parts of the study area shows that each location in the study area could be appropriate for one of the storage effectiveness metrics. Therefore, we conclude that the screening process to select the best site for CO2 sequestration should be based on an evaluation of all three metrics. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract The hybrid process of carbonated low salinity waterflood (CLSWF) integrating low salinity waterflood (LSWF) and carbonated waterflood (CWF) is proposed as enhanced oil recovery (EOR) incorporating CO2 storage. Based on the understanding of the mechanisms of LSWF and CWF, the hybrid technology is simulated with a fully‐coupled model of fluid flow, geochemical reactions, and equation of state, which describes chemical interactions in the oil/brine/rock system. The comprehensive simulations confirm the synergetic effects of the hybrid CLSWF when compared to waterflooding (WF) and LSWF. In addition, optimum designs of cost‐efficient CLSWF securing CO2 storage are drawn via optimization and sensitivity studies. First, CLSWF enhances wettability modification effect, when compared to LSWF. In CLSWF, extensive mineral dissolution causes more cation exchange. Following the multicomponent ion exchange theory of the wettability modification mechanism, CLSWF produces more residual oil than LSWF with an increasing equivalent fraction of cation. Consequently, it enhances oil recovery by 6.9% and 2.5%, compared with WF and LSWF. Second, the interphase transport of CO2 introduces the oil viscosity reduction effect, which improves the injectivity of CLSWF. Lastly, it sequestrates 25% of the injected CO2 in the depleted reservoir via the solubility‐trapping mechanism. In optimization and sensitivity studies, the optimum design of CLSWF is determined to produce more oil recovery by 9.9% and more net present value by 35% over WF. In addition, 33% of the injected CO2 becomes sequestrated in the reservoirs. This study clarifies that hybrid CLSWF improves EOR, injectivity, and CO2 storage. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Fertilizer management and straw returning are effective measures to regulate greenhouse gas emissions and increase crop yields, which have attracted wide attention in agricultural production. To clarify the effect of Chinese milk vetch returning with nitrogen fertilizer on rice yield and greenhouse gas emissions in paddy field, field experiments were conducted during 2017–2018 and four treatments were proposed in this study, including the treatments with Chinese milk vetch returning plus different nitrogen fertilizer application amount, namely RA, RB, RC, and control CK (winter fallow without Chinese milk vetch returning). The results showed that treatments RA, RB, and RC significantly increased the early rice yield by 15.35%, 12.94%, and 15.35%, respectively (P〈0.05), and treatment RA had the best effect on the annual yield (P〈0.05) compared with control CK. Meanwhile, all the treatments with Chinese milk vetch returning plus nitrogen fertilizer increased the global warming potential, but the difference between RA, RB, and control CK was not significant (P〉0.05); the greenhouse gas intensity produced by RA was 11.76% lower than control CK. In summary, treatment RA, followed by RB, had the best effect in increasing rice production and reducing greenhouse gas emissions in paddy fields. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Two parameters that play the most important role in the appraisal of environmental risk performance at carbon dioxide (CO2) storage sites are the prospective impact of the pore pressure increase and CO2 saturation. In this context, this study investigates the spatiotemporal evolution of pressure buildup and CO2 saturation as a function of flow region's size, average porosity and permeability, and heterogeneity, as well as the injection rate and total volume of injected fluid. The practical importance of this study is to investigate the factors that affect the extent of pressure buildup and areal extent of CO2 plume both during and after injection, which will impact risk assessment as well as influence effective monitoring operations. This study pursues the above objective using two risk metrics that are based on numerical simulations and illustrated using representative models of three realistic storage sites with varying volumetric storage potential and geological settings, all with open geologic systems. The two metrics (the spatiotemporal extent of pressure buildup and CO2 saturation plume, respectively) used in this study are able to capture the geologic (structural and petrophysical) and operational complexities that cannot be incorporated into analytical or semianalytical solutions. The results of this study suggest that in addition to the average permeability, the areal extent of the pressure buildup during the injection period is strongly related to the injection rate, whereas the postinjection period may be more strongly influenced by the reservoir heterogeneity. The areal extent of the saturation plume during active injection is highly correlated to the mass of injected fluid, and the postinjection behavior is impacted by the shape of the reservoir–seal interface. These findings are consistent with other recent studies by the National Risk Assessment Partnership (NRAP) on characteristic reservoir behavior. The results have been used to generate pressure and saturation plume profiles (over time) that can be used to support risk‐based decision making. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Multiple environmental stressors impact wildlife populations, but we often know little about their cumulative and combined influences on population outcomes. We generally know more about past effects than potential future impacts, and direct influences such as changes of habitat footprints than indirect, long‐term responses in behavior, distribution, or abundance. Yet, an understanding of all these components is needed to plan for future landscapes that include human activities and wildlife. We developed a case study to assess how spatially explicit individual‐based modeling could be used to evaluate future population outcomes of gradual landscape change from multiple stressors. For Greater Sage‐grouse in southwest Wyoming, USA, we projected oil and gas development footprints and climate‐induced vegetation changes 50 years into the future. Using a time‐series of planned oil and gas development and predicted climate‐induced changes in vegetation, we recalculated habitat selection maps to dynamically modify future habitat quantity, quality, and configuration. We simulated long‐term Sage‐grouse responses to habitat change by allowing individuals to adjust to shifts in habitat availability and quality. The use of spatially explicit individual‐based modeling offered a useful means of evaluating delayed indirect impacts of landscape change on wildlife population outcomes. The inclusion of movement and demographic responses to oil and gas infrastructure resulted in substantive changes in distribution and abundance when cumulated over several decades and throughout the regional population. When combined, additive development and climate‐induced vegetation changes reduced abundance by up to half of the original size. In our example, the consideration of only a single population stressor the final possible population size by as much as 50%. Multiple stressors and their cumulative impacts need to be broadly considered through space and time to avoid underestimating the impacts of multiple gradual changes and overestimating the ability of populations to withstand change.

Beschreibung: Abstract Understanding the factors associated with declines of at‐risk species is an important first step in setting management and recovery targets. This step can be challenging when multiple aspects of climate and land use are changing simultaneously, and any or all could be contributing to population declines. We analyzed population trends of monarch butterflies in western North America in relation to likely environmental drivers. Unlike the larger eastern monarch population, past analyses of western monarchs have only evaluated the importance of climate (i.e., not land use) factors as drivers of abundance. We used partial least squares regression (PLSR) to evaluate the potential importance of changes in land use and climate variables. Trends in western monarch abundance were more strongly associated with land use variables than climate variables. Conclusions about importance of climate and land use variables were robust to changes in PLSR model structure. However, individual variables were too collinear to unambiguously separate their effects. We compared these conclusions to the more widely used technique of multiple regression, followed by multi‐model inference (MRMI). Naïve interpretation of MRMI results could be misleading, if collinearity were not taken into account. MRMI was also highly sensitive to variation in model construction. Our results suggest a two‐pronged approach to monarch conservation, specifically, starting efforts now to restore habitat, while also using experiments to more clearly delineate separate effects of climate and land use factors. They also demonstrate the utility of PLSR, a technique that is growing in use but is still relatively under‐appreciated in conservation biology. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Winter is an understudied but key period for the socio‐ecological systems of northeastern North American forests. A growing awareness of the importance of the winter season to forest ecosystems and surrounding communities has inspired several decades of research, both across the northern forest and at other mid‐ and high‐latitude ecosystems around the globe. Despite these efforts, we lack a synthetic understanding of how winter climate change may impact hydrological and biogeochemical processes and the social and economic activities they support. Here we take advantage of 100 years of meteorological observations across the northern forest region of the northeastern U.S. and eastern Canada to develop a suite of indicators that enable a cross‐cutting understanding of 1) how winter temperatures and snow cover have been changing and 2) how these shifts may impact both ecosystems and surrounding human communities. We show that cold and snow‐covered conditions have generally decreased over the past 100 years. These trends suggest positive outcomes for tree health as related to reduced fine root mortality and nutrient loss associated with winter frost but negative outcomes as related to the northward advancement and proliferation of forest insect pests. In addition to effects on vegetation, reductions in cold temperatures and snow cover are likely to have negative impacts on the ecology of the northern forest through impacts on water, soils, and wildlife. The overall loss of coldness and snow cover may also have negative consequences for logging and forest products, vector‐borne diseases and human health, recreation and tourism, and cultural practices, which together represent important social and economic dimensions for the northern forest region. These findings advance our understanding of how our changing winters may transform the socio‐ecological system of a region that has been defined by the contrasting rhythm of the seasons. Our research also identifies a trajectory of change that informs our expectations for the future as the climate continues to warm. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Climate‐change projections suggest large changes in riverine flow regime, which will likely alter riparian communities. In northern Europe, forecasts propose lower annual spring flood peaks and higher winter flows, resulting in narrower riparian zones. To estimate the impact of climate change on habitat extent of riparian plants, we developed a framework estimating the sensitivity and exposure of individual species to streamflow change, and surveyed five reaches along the free‐flowing Vindel River in northern Sweden. We modeled the hydrologic niche of riparian plant species based on the probability of occurrence along gradients of flood frequency and duration, and used predicted future water‐level fluctuations (based on climate models and IPCC emission scenarios) to calculate changes in flow‐related habitat availability of individual species. Despite projected increases in run‐off, we predict most species to decrease in riparian elevational extent by on average 12−29% until the end of the century, depending on scenario. Species growing in the upper, spring‐flood controlled part of the riparian zone will likely lose most habitat, with the largest reductions in species with narrow ranges of inundation duration tolerance (decreases of up to 54%). In contrast, the elevational extent of most amphibious species is predicted to increase, but conditions creating isoëtid vegetation will become rarer or disappear: Isoëtid vegetation is presently found in areas where ice formed in the fall settles on the riverbank during the winter as water levels subside. Higher winter flows will make these conditions rare. We argue that our framework is useful to project the effects of hydrologic change caused by climate change as well as other stressors such as flow regulation also in other regions. With few rivers remaining unaffected by dams and other human stressors, these results call for monitoring to detect species declines. Management to alleviate species losses might include mitigation of habitat degradation from land‐use activities, more environmentally‐friendly flow schemes, and more intensive management options such as mowing riparian meadows no longer regularly maintained by recurrent floods. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Pastureland currently occupies 26% of Earth's ice‐free land surface. As the global human population continues to increase and developing countries consume more protein‐rich diets, the amount of land devoted to livestock grazing will only continue to rise. To mitigate the loss of global biodiversity as a consequence of the ever‐expanding amount of land converted from native habitat into pastureland for livestock grazing, an understanding of how livestock impact wildlife is critical. While previous reviews have examined the impact of livestock on a wide variety of taxa, there have been no reviews examining how global livestock grazing affects amphibians. We conducted both an empirical study in south‐central Florida examining the impact of cattle on amphibian communities and a quantitative literature review of similar studies on five continents. Our empirical study analyzed amphibian community responses to cattle as both a binary (presence/absence) variable, and as a continuous variable based on cow pie density. Across all analyses, we were unable to find any evidence that cattle affected the amphibian community at our study site. The literature review returned 46 papers that met our criteria for inclusion. Of these studies, 15 found positive effects of livestock on amphibians, 21 found neutral/mixed effects, and 10 found negative effects. Our quantitative analysis of these data indicates that amphibian species that historically occurred in closed‐canopy habitats are generally negatively affected by livestock presence. In contrast, open‐canopy amphibians are likely to experience positive effects from the presence of livestock, and these positive effects are most likely to occur in locations with cooler climates and/or greater precipitation seasonality. Collectively, our empirical work and literature review demonstrate that under the correct conditions well‐managed rangelands are able to support diverse assemblages of amphibians. These rangeland ecosystems may play a critical role in protecting future amphibian biodiversity by serving as an “off‐reserve” system to supplement the biodiversity conserved within traditional protected areas. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Regional heterogeneity during low‐carbon economy development among provinces in China should be considered with more concerns by central government. Spatial coordination can bring more opportunities for underdeveloped provinces. Under this background, provincial low‐carbon economy transformation performance is evaluated during 2000–2016 and spatial characters are analyzed to supply detailed development information. Based on parametric input–output evaluation model and linear programming method, provincial low‐carbon economy transformation performance is evaluated. Spatial analysis methods such as Moran index, Moran scatter diagram, and Markov chain are implemented to analyze their spatial characters and dynamic trends. Main results are as follows: First, linear programing supplies reliable parameter results to evaluate the transformation performance. Mean value rises during 2000−2011 and there is a slight downward trend during 2013−2016. Economy transformation performance is still at lower medium level for most provinces nowadays and there is a long way to go further. Second, according to Markov chain results, more than 90% provinces exist as state self‐locking and less than 10% may exist as state jumping. Third, spatial correlation exists among provinces and ‘lower−lower’ type dominates with respect to low‐carbon economy transformation performance. They are mainly underdeveloped provinces in northwestern China. Absorbing greener production technology is the best choice for them. Yangtze River Delta provinces such as Shanghai, Jiangsu, and Zhejiang are of ‘higher–higher’ type. Regional cooperatives can exert lots of potentials and are beneficial to stimulate transformation performance. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract The chemical absorption process for carbon dioxide (CO2) capture is a promising method to reduce greenhouse gas emissions in the energy industry. Worldwide applications of the CO2 chemical absorption process will consume plenty of chemical absorbents and have hazardous impacts on the environment. The development of renewable absorbents from biomass can not only fill the gap of absorbent production, but also provide a novel green approach to recycle the used absorbents into nature without additional pollution. In this review, we summarized several renewable absorbents available from biomass such as biomass ash slurries, alkanolamines, aqueous ammonia, and amino acid salts. The preparations, CO2 absorption capacities, advanced treatments, and applications of the renewable absorbents were also reviewed. Moreover, the advantages and challenges in the preparation of the renewable absorbents were discussed, as well as their CO2 absorption performance improvement. Finally, future research avenues into degradation and utilization of renewable absorbents in nature were suggested. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract In order to understand how the effects of land‐use change vary among taxa and environmental contexts, we investigate how three types of land‐use change have influenced phylogenetic diversity (PD) and species composition of three functionally distinct communities: plants, small mammals, and large mammals. We found large mammal communities were by far the most heavily impacted by land‐use change, with areas of attempted large wildlife exclusion and intense livestock grazing respectively containing 164 and 165 million fewer years of evolutionary history than conserved areas (~40% declines). The effects of land‐use change on PD varied substantially across taxa, type of land‐use change, and, for most groups, also across abiotic conditions. This highlights the need for taxa‐specific or multi‐taxa evaluations, for managers interested in conserving specific groups or whole communities, respectively. It also suggests that efforts to conserve and restore PD may be most successful if they focus on areas of particular land‐use types and abiotic conditions. Importantly, we also describe the substantial species turnover and compositional changes that cannot be detected by alpha diversity metrics, emphasizing that neither PD nor other taxonomic diversity metrics are sufficient proxies for ecological integrity. Finally, our results provide further support for the emerging consensus that conserved landscapes are critical to support intact assemblages of some lineages such as large mammals, but that mosaics of disturbed land‐uses, including both agricultural and pastoral land, do provide important habitats for a diverse array of plants and small mammals. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract We develop plume migration metrics based on spatial moment analysis methods that quantify the spatio‐temporal evolution of plumes at geologic CO2 storage sites. The metrics are generalized to handle any 3‐D scalar attribute field values. Within the geologic CO2 storage context, these can be parameters such as CO2 saturation, effective pressure, overpressure, dissolved CO2 concentration, total dissolved solids, pH, and other attributes that are critical for assessing risks. The metrics are comprehensive in that they can effectively handle and account for complex continuous and discontinuous plumes and intra‐plume migration. We demonstrate the metrics on simulated CO2 plumes injected into flat and tilted reservoirs with homogeneous and heterogeneous permeability fields. Using these idealized reservoir scenarios, we demonstrate the information that the metrics extract, showing that the metrics elucidate nuances in plume migration not apparent by standard approaches to the scalar fields values. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.

Beschreibung: Abstract Porous carbon fibers (PCFs) were prepared from porous polyacrylonitrile fibers by cross‐linking, oxidation, and carbonization. X‐ray diffraction patterns revealed that graphite structures as well as disordered carbon coexisted in the PCFs. Nitrogen content was more than 15.3 wt% with the variation of oxidation temperature, and a maximum value was obtained at 275°C. Nitrogen was quickly released with carbonization temperature. Compared with the fiber prepared at elevated carbonization temperatures, those owning high nitrogen contents deserved better carbon dioxide (CO2) adsorption performance in the simulated flue gas environment (10% CO2/90% N2). The CO2 adsorption had a better relationship with nitrogen content rather than specific surface area and pore volumes. Especially, nitrogen was very useful to enhance the CO2 adsorption of the fibers with low microporosity. The heat of CO2 adsorption was in the range of 39.8–54.6 kJ mol−1, which indicated good selectivity of CO2 adsorption. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Sulfur dioxide (SO2) and carbon dioxide (CO2) removals are of great significance for fossil fuel combustion, where they can be simultaneously captured by calcium‐based absorbents. Nevertheless, the CO2 uptake capacity declines with SO2 partial pressures. This paper aims at explaining the mechanisms of steam‐declined sulfation and steam‐enhanced carbonation by density functional theory calculations. CaO(001) surface is chosen as the absorbent, and the transition state is calculated to obtain the desorption barrier energy of the adsorbates. By analyzing the desorption of the adsorbate on pristine CaO(001) surface and the CaO(001) surface that has adsorbed other adsorbate, it can be concluded that SO2 adsorption inhibits CO2 adsorption since the barrier energy of CO2 desorption on SO2‐CaO(001) surface (24.15 kJ mol–1) is less than CO2 desorption on CaO(001) surface (129.52 kJ mol–1). By comparing the coadsorption energy of the two adsorbates with the sum of the adsorption energy of each adsorbate, it is practical that the H2O adsorption inhibits SO2 adsorption because the calculated coadsorption energy (−221.27 kJ mol–1) is larger than the sum of H2O adsorption energy (–100.00 kJ mol–1) and SO2 adsorption energy (−194.37 kJ mol–1). However, the calculated coadsorption energy of H2O and CO2 adsorption (−254.89 kJ mol–1) is less than the sum of CO2 adsorption energy (−144.23 kJ mol–1) and H2O adsorption energy (−100.00 kJ mol–1), indicating the promotion of CO2 adsorption. Steam in the adsorption process plays the roles of sulfation suppression and carbonation enhancement. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract CO2 storage in different geological formations has been recognized as one of the promising mitigation approaches to reduce the emission of CO2 into the atmosphere. There are many complex hydro‐chemo‐mechanical interactions (effective stress changes, water acidification, and mineral dissolution) that may take place in a storage site during or after injection, reducing the integrity of formations in the short or long term. Although there have been several studies carried out in the past to assess the feasibility of sandstones and limestone formations as a safe CO2 storage site, the effect of hydrological, mechanical, and chemical processes on the storage site integrity has not been deeply addressed. The aim of this study is to couple thermo‐hydro‐chemo‐mechanical processes upon CO2 injection and assess their impact on the key storage aspects of quartz‐rich sandstone and calcite‐rich limestone. A numerical model was built to simulate CO2 flooding into a saline aquifer with sandstone and limestone composition for 500 years. The results obtained indicated that geochemical activity and CO2 dissolution are significantly higher in limestone and may increase the porosity by ∼16%. During injection, a decrease in the reservoir strength was observed in both rock types upon exposure to CO2. A remarkable variation in the geomechanical characteristics was also revealed in the sandstone after injection. However, ground displacements (subsidence) of 0.0017 and 0.033 m were, respectively, observed in sandstone and limestone aquifers, at the end of 500 years. It is recommended to consider a high‐strength reservoir for carbon capture and storage (CCS) projects in order to reduce the likelihood of compaction. It was also found that both rock types have a good storage capacity, injectivity, and trapping potentials (the structural and dissolution trappings) to capture and hold CO2 in place. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Effective environmental assessment and management requires quantifiable biodiversity targets. Biodiversity benchmarks define these targets by focusing on specific biodiversity metrics, such as species richness. However, setting fixed targets can be challenging because many biodiversity metrics are highly variable, both spatially and temporally. We present a multivariate, hierarchical Bayesian method to estimate biodiversity benchmarks based on the species richness and cover of native terrestrial vegetation growth forms. This approach uses existing data to quantify the empirical distributions of species richness and cover within growth forms, and we use the upper quantiles of these distributions to estimate contemporary, “best‐on‐offer” biodiversity benchmarks. Importantly, we allow benchmarks to differ among vegetation types, regions, and seasons, and with changes in recent rainfall. We apply our method to data collected over 30 years at c. 35 000 floristic plots in south‐eastern Australia. Our estimated benchmarks were broadly consistent with existing expert‐elicited benchmarks, available for a small subset of vegetation types. However, in comparison with expert‐elicited benchmarks, our data‐driven approach: is transparent, repeatable and updatable; accommodates important spatial and temporal variation; aligns modelled benchmarks directly with field data and the concept of best‐on‐offer benchmarks; and, where many benchmarks are required, is likely to be more efficient. Our approach is general and could be used broadly to estimate biodiversity targets from existing data in highly variable environments, which is especially relevant given rapid changes in global environmental conditions.

Beschreibung: Abstract The availability and quality of forage on the landscape constitute the foodscape within which animals make behavioral decisions to acquire food. Novel changes to the foodscape, such as human disturbance, can alter behavioral decisions that favor avoidance of perceived risk over food acquisition. Although behavioral changes and population declines often coincide with the introduction of human disturbance, the link(s) between behavior and population trajectory are difficult to elucidate. To identify a pathway by which human disturbance may affect ungulate populations, we tested the Behaviorally Mediated Forage‐Loss Hypothesis, wherein behavioral avoidance is predicted to reduce use of available forage adjacent to disturbance. We used GPS‐collar data collected from migratory mule deer (Odocoileus hemionus) to evaluate habitat selection, movement patterns, and time‐budgeting behavior in response to varying levels of forage availability and human disturbance in three different populations exposed to a gradient of energy development. Subsequently, we linked animal behavior with measured use of forage relative to human disturbance, forage availability, and quality. Mule deer avoided human disturbance at both home range and winter range scales, but showed negligible differences in vigilance rates at the site level. Use of the primary winter forage, sagebrush (Artemisia tridentata), increased as production of new annual growth increased but use decreased with proximity to disturbance. Consequently, avoidance of human disturbance prompted loss of otherwise available forage, resulting in indirect habitat loss that was 4.6‐times greater than direct habitat loss from roads, well pads, and other infrastructure. The multiplicative effects of indirect habitat loss, as mediated by behavior, impaired use of the foodscape by reducing the amount of available forage for mule deer—a consequence of which may be winter ranges that support fewer animals than they did before development. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract The international seed trade is considered relatively safe from a phytosanitary point of view and is therefore less regulated than trade in other plants for planting. However, the pests carried by traded seeds are not well known. We assessed insects and fungi in 58 traded seed lots of eleven gymnosperm and angiosperm tree species from North America, Europe and Asia. Insects were detected by x‐raying and molecular methods. The fungal community was characterised using high‐throughput sequencing (HTS) and by growing fungi on non‐selective agar. About 30% of the seed lots contained insect larvae. Gymnosperms contained mostly hymenopteran (Megastigmus spp.) and dipteran (Cecidomyiidae) larvae, while angiosperms contained lepidopteran (Cydia latiferreana) and coleopteran (Curculio spp.) larvae. HTS indicated the presence of fungi in all seed lots and fungi grew on non‐selective agar from 96% of the seed lots. Fungal abundance and diversity were much higher than insect diversity and abundance, especially in angiosperm seeds. Almost 50% of all fungal Exact Sequence Variants (ESVs) found in angiosperms were potential pathogens, in comparison with around 30% of potentially pathogenic ESVs found in gymnosperms. The results of this study indicate that seeds may pose a greater risk of pest introduction than previously believed or accounted for. A rapid risk assessment suggests that only a small number of species identified in this study is of phytosanitary concern. However, more research is needed to enable better risk assessment, especially to increase knowledge about the potential for transmission of fungi to seedlings and the host range and impact of identified species. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract The environmental problems caused by global warming have attracted close attention of governments and scientists all over the world. As the source and sink of atmospheric carbon dioxide, cropland soil plays an important role in the global carbon cycle. Paddy soil is a major component of global cropland, and there is growing research on its carbon sequestration potential. Based on the dynamic characteristics of soil carbon sequestration in cropland, this paper reviews and synthesizes the process and mechanism of soil carbon sequestration in cropland, discusses the driving factors of soil carbon sequestration in cropland from the perspective of crop management practices, and emphatically discusses the knowledge of soil carbon sequestration potential in paddy fields in China. The main conclusions are as follows: (1) The organic carbon content of cropland soil in China is obviously lower than the global average, and the current sequestration rate of paddy soil in China is obviously lower than the potential sequestration rate, which has great potential for carbon sequestration. Since the mid‐1980s, China's agricultural soil organic carbon (SOC) has been gradually increasing, especially the carbon sink effect of rice soil in southern China. (2) Soil and crop management practices such as conservation agriculture, irrigation, integrated nutrition management, straw returning, and crop rotation can improve input efficiency, increase SOC content in the soil carbon pool, and reduce greenhouse gas emissions. (3) The research on SOC fixation mechanism has entered the micro level of soil particles. The chemical protection mechanism of clay, the physical protection mechanism of aggregates, and the biological mechanism interact and influence each other. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Using a solid Na‐based sorbent is one potential option to decrease CO2 emission in coal‐fired power plants, and the CO2 sorption reactivity of Na2CO3/γ‐Al2O3 sorbent was improved by mechanically doping MgO into Na2CO3/γ‐Al2O3 in our previous study while the mechanism was not clear. In this paper, the CO2 sorption/desorption mechanisms of the promising MgO‐doped Na‐based sorbent prepared by the two‐step incipient wetness impregnation method were studied using a fixed‐bed reactor, together with characterizations of X‐ray fluorescence, nitrogen adsorption apparatus, field emission scanning electron microscopy, X‐ray diffraction, and thermogravimetric analyzer coupled with Fourier transform infrared spectrometer (TG‐FTIR). Also, the sorption behaviors were well described with Avrami's fractional‐order kinetic model. Results demonstrated that MgO not only dispersed on γ‐Al2O3 but entered γ‐Al2O3’s lattice, leading to the formation of Mg‐Al mixed oxides for CO2 sorption. In addition, a new phase Mg6Al2CO3(OH)16·4H2O was produced during the CO2 sorption process, which plays a crucial role in facilitating the conversion of Na2CO3 to NaHCO3. The CO2 sorption capacity of MgO‐doped Na‐based sorbents is presumably determined by the trade‐off between microstructure and active component dispersion. The knowledge gained about the promotion mechanism of MgO provides fundamental direction for the synthesis of Mg–Al mixed oxides, supported with the developed microstructure for CO2 sorption enhancement of Na‐based sorbents. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Beschreibung: Abstract Benefitting from reduced harvesting and an end to culling, many marine mammals are now recovering from past overexploitation. These recoveries represent important conservation successes but present a serious conservation problem when the recovering mammals are predators of species of conservation concern. Here, we examine the role of predation by recovering grey seals (Halichoerus grypus) in the near‐extinction of a unique skate population in the southern Gulf of St. Lawrence (sGSL) in Atlantic Canada. Winter skate (Leucoraja ocellata) in the sGSL are distinct from winter skate elsewhere and may represent an endemic species. Their adult abundance has declined by 98% since 1980, and these skates are now detectable in only a small fraction of their former range. Population modeling indicates that the ongoing collapse of this population is due to increases in the natural mortality of adults. Based on model projections, this population would be extinct by mid‐century if its current rate of productivity were to persist. A second population model incorporated predation by grey seals. Model estimates of skate consumption by seals were consistent with historical and recent estimates of the contribution of skates to grey seal diets. The estimated consumption accounted for the increases in the natural mortality of adult skates. A Type III functional response for grey seals preying on winter skate emerged from the model results. This indicates that, when skate abundance is very low, grey seals are expected to switch to alternate prey, resulting in declines in the mortality of skates due to predation. Consequently, contrary to projections at current productivity, winter skate are expected to be trapped at very low abundance in a “predator pit” instead of declining to extinction. Nonetheless, extinction risk would remain very high at the very small population size in the predator pit. Our results emphasize the need for an ecosystem‐based approach to the management of living resources in this ecosystem.

Beschreibung: Abstract Species that are primarily seral may form stable (self‐sustaining) communities under certain disturbance regimes or environmental conditions, yet such populations may also be particularly vulnerable to ecological change. Aspen (Populus spp.) are generally considered seral throughout the northern hemisphere, including P. tremuloides, the most widely distributed tree species in North America. Recent declines in aspen populations have occurred, especially along drought‐sensitive margins of its range and where fire exclusion and herbivory have promoted community transition. However, aspen also forms stable stands, and examination of the mechanisms that influence persistence can offer conservation insights, especially where populations are vulnerable to changing climate or altered disturbance dynamics. We sampled tree age and stand characteristics of isolated aspen forests in the arid Great Basin (USA) to determine if: (1) aspen communities are more fire‐dependent and seral or fire‐independent and stable; (2) ungulate browsing inhibits aspen stability; and (3) temporal patterns of vegetative reproduction (i.e., ramet establishment or “suckering”) are correlated with climate. Aspen size and age class densities strongly fit negative exponential distributions, whether grouped geographically or by functional type, suggesting landscape‐scale persistence. Continuous age distributions and high proportions of recruitment‐sized to overstory trees suggest stability at stand‐scales, with exceptions including stands with higher browsing pressure. Few stands had evidence of fire, and relationships between dead tree size and variability in live tree size suggest a lack of fire‐dependency. Several five‐year averaged climate variables and one sea surface temperature index were correlated with aspen ramet establishment densities over time, with strongest relationships occurring ~5 years prior to establishment year, often followed by inverse relationships ~1 year after. Indeed, aspen establishment density for a recent 41‐year period was reliably reconstructed using antecedent climate conditions derived from a single drought index. Temporally synchronized aspen ramet establishment across the study region may be due to climate‐driven storage of nonstructural carbohydrate reserves in clonal root systems later used for regeneration. Complex regeneration dynamics of these self‐sustaining aspen stands, especially sensitivity to climate variability, suggest they may serve as harbingers of ecological change in the arid Great Basin and in other aspen populations near their range margin. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Concerns exist about the impacts of underwater noise on marine mammals. These include auditory damage, which is a significant risk for marine mammals exposed to impulsive sounds such as explosions, pile‐driving, and seismic air guns. Currently, impact assessments use different risk criteria for impulsive and non‐impulsive sounds (e.g., ships, drilling). However, as impulsive sounds dissipate through the environment, they potentially lose hazardous features (e.g., sudden onset) and become non‐impulsive at some distance from the source. Despite management implications, a lack of data on range‐dependent characteristics currently limits their inclusion in impact assessments. We address this using acoustic recordings of seismic air guns and pile‐driving to quantify range dependency in impulsive characteristics using four criteria: (1) rise time 〈 25 ms; (2) quotient of peak pressure and pulse duration 〉 5,000 Pa/s; (3) duration 〈 1 s; (4) crest factor 〉 15 dB. We demonstrate that some characteristics changed markedly within ranges of ~10 km, and that the mean probability of exceeding criteria 1 and 2 was 〈0.5 at ranges 〉3.5 km. In contrast, the mean probability of exceeding criteria 3 remained 〉0.5 up to ~37.0 km, and the mean probability of exceeding criteria 4 remained 〈0.5 throughout the range. These results suggest that a proportion of the recorded signals should be defined as impulsive based on each of the criteria, and that some of the criteria change markedly as a result of propagation. However, the impulsive nature of a sound is likely to be a complex interaction of all these criteria, and many other unrelated parameters such as duty cycle, recovery periods, and sound levels will also strongly affect the risk of hearing damage. We recommend future auditory damage studies and impact assessments explicitly consider the ranges at which sounds may lose some of their potentially hazardous characteristics.

Beschreibung: Abstract Multiple global change drivers are increasing the present and future novelty of environments and ecological communities. However, most assessments of environmental novelty have focused only on future climate and were conducted at scales too broad to be useful for land management or conservation. Here, using historical county‐level datasets of agricultural land use, forest composition, and climate, we conduct a regional‐scale assessment of environmental novelty for Wisconsin landscapes from ca. 1890 to 2012. Agricultural land‐use data include six cropland types, livestock densities for four livestock species, and human populations. Forestry data comprise biomass‐weighted relative abundances for 15 tree genera. Climate data comprise seasonal means for temperature and precipitation. We found that forestry and land use are the strongest cause of environmental novelty (NoveltyForest=3.66, NoveltyAg.=2.83, NoveltyClimate=1.60, with Wisconsin's forests transformed by early 20th‐century logging and its legacies and multiple waves of agricultural innovation and obsolescence. Climate change is the smallest contributor to contemporary novelty, with precipitation signals stronger than temperature. Magnitudes and causes of environmental novelty are strongly spatially patterned, with novelty in southern Wisconsin roughly twice that in northern Wisconsin. Forestry is the most important cause of novelty in the north, land use and climate change are jointly important in the southwestern Wisconsin, and land use and forest composition are most important in central and eastern Wisconsin. Areas of high regional novelty tend also to be areas of high local change, but local change has not pushed all counties beyond regional baselines. Seven counties serve as the best historical analogues for over half of contemporary Wisconsin counties (40/72), and so can offer useful historical counterparts for contemporary systems and help managers coordinate to tackle similar environmental challenges. Multi‐dimensional environmental novelty analyses, like those presented here, can help identify the best historical analogues for contemporary ecosystems, places where new management rules and practices may be needed because novelty is already high, and the main causes of novelty. Separating regional novelty clearly from local change and measuring both across many dimensions and at multiple scales thus helps advance ecology and sustainability science alike. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Assessing the statistical power to detect changes in wildlife populations is a crucial yet often overlooked step when designing and evaluating monitoring programs. Here, we developed a simulation framework to perform spatially explicit statistical power analysis of biological monitoring programs for detecting temporal trends in occupancy for multiple species. Using raster layers representing the spatial variation in current occupancy and species‐level detectability for one or multiple observation methods, our framework simulates changes in occupancy over space and time, with the capacity to explicitly model stochastic disturbances at monitoring sites (i.e., dynamic landscapes). Once users specify the number and location of sites, the frequency and duration of surveys, and the type of detection method(s) for each species, our framework estimates power to detect occupancy trends, both across the landscape and/or within nested management units. As a case study, we evaluated power of a long‐term monitoring program to detect trends in occupancy for 136 species (83 birds, 33 reptiles and 20 mammals) across and within Kakadu, Litchfield and Nitmiluk National Parks in northern Australia. We assumed continuation of an original monitoring design implemented since 1996, with the addition of camera‐trapping. As expected, power to detect trends was sensitive to the direction and magnitude of the change in occupancy, detectability, initial occupancy levels, and the rarity of species. Our simulations suggest that monitoring has at least an 80% chance at detecting a 50% decline in occupancy for 22% of species across the three parks over the next 15 years. Monitoring is more likely to detect increasing occupancy trends, with at least an 80% chance at detecting a 50% increase in 87% of species. The addition of camera‐trapping increased average power to detect a 50% decline in mammals compared with using only live trapping by 63%. We provide a flexible tool that can help decision‐makers design and evaluate monitoring programs for hundreds of species at a time in a range of ecological settings, while explicitly considering the distribution of species and alternative sampling methods. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract Telemetry is a key, widely‐used tool to understand marine megafauna distribution, habitat use, behaviour, and physiology, however, a critical question remains: “how many animals should be tracked to acquire meaningful datasets?” This question has wide‐ranging implications including considerations of statistical power, animal ethics, logistics and cost. While power analyses can inform sample sizes needed for statistical significance, they require some initial data inputs that are often unavailable. To inform the planning of telemetry and biologging studies of marine megafauna where few or no data are available or where resources are limited, we reviewed the types of information that have been obtained in previously published studies using different sample sizes. We considered sample sizes from one to more than 100 individuals and synthesized empirical findings, detailing the information that can be gathered with increasing sample sizes. We complement this review with simulations, using real data, to show the impact of sample size when trying to address various research questions in movement ecology of marine megafauna. We also highlight the value of collaborative, synthetic studies to enhance sample sizes and broaden the range, scale, and scope of questions that can be answered. This article is protected by copyright. All rights reserved.

Beschreibung: Abstract The continually increasing global population residing in urban landscapes impacts numerous ecosystem functions and services provided by urban streams. Urban stream restoration is often employed to offset these impacts and conserve or enhance the various functions and services these streams provide. Despite the assumption that “if you build it, [the function] will come,” current understanding of the effects of urban stream restoration on stream ecosystem functions are based on short term studies that may not capture variation in restoration effectiveness over time. We quantified the impact of stream restoration on nutrient and energy dynamics of urban streams by studying 10 urban stream reaches (five restored, five unrestored) in the Baltimore, Maryland, USA, region over a two‐year period. We measured gross primary production (GPP) and ecosystem respiration (ER) at the whole‐stream scale continuously throughout the study and nitrate (NO3−‐N) spiraling rates seasonally (spring, summer, autumn) across all reaches. There was no significant restoration effect on NO3−‐N spiraling across reaches. However, there was a significant canopy cover effect on NO3−‐N spiraling, and directly comparing paired sets of unrestored‐restored reaches showed that restoration does affect NO3−‐N spiraling after accounting for other environmental variation. Furthermore, there was a change in GPP : ER seasonality, with restored and open‐canopied reaches exhibiting higher GPP : ER during summer. The restoration effect, though, appears contingent upon altered canopy cover, which is likely to be a temporary effect of restoration and is a driver of multiple ecosystem services, e.g., habitat, riparian nutrient processing. Our results suggest that decision‐making about stream restoration, including evaluations of nutrient benefits, clearly needs to consider spatial and temporal dynamics of canopy cover and trade‐offs among multiple ecosystem services.

Beschreibung: Abstract Adaptive management of marine protected areas (MPAs) requires developing methods to evaluate whether monitoring data indicate that they are performing as expected. Modeling the expected responses of targeted species to a MPA network, with a clear timeline for those expectations, can aid in the development of a monitoring program that efficiently evaluates expectations over appropriate time frames. Here we describe the expected trajectories in abundance and biomass following MPA implementation for populations of 19 nearshore fishery species in California. To capture the process of filling in the age structure truncated by fishing, we used age‐structured population models with stochastic larval recruitment to predict responses to MPA implementation. We implemented both demographically open (high larval immigration) and closed (high self‐recruitment) populations to model the range of possible trajectories as they depend on recruitment dynamics. From these simulations, we quantified the time scales over which anticipated increases in abundance and biomass inside MPAs would become statistically detectable. Predicted population biomass responses range from little change, for species with low fishing rates, to increasing by a factor of nearly seven, for species with high fishing rates before MPA establishment. Increases in biomass following MPA implementation are usually greater in both magnitude and statistical detectability than increases in abundance. For most species, increases in abundance would not begin to become detectable for at least ten years after implementation. Overall, these results inform potential indicator metrics (biomass), potential indicator species (those with a high fishing:natural mortality ratio), and time frame (〉10 years) for MPA monitoring assessment as part of the adaptive management process. This article is protected by copyright. All rights reserved.