ALBERT

Description: A changing climate and more frequent extreme weather events pose challenges to the oil and gas sector. Identifying how these changes will affect oil and gas extraction, transportation, processing, and delivery, and how these industries can adapt to or mitigate any adverse impacts will be vital to this sector’s supply security. This work presents an overview of the sector’s vulnerability to a changing climate. It addresses the potential for Natech hazards and proposes risk reduction measures, including mitigation and adaptation options. Assessment frameworks to ensure the safety of people, the environment, and investments in the oil and gas sector in the face of climate change are presented and their limitations discussed. It is argued that a comprehensive and systemic analysis framework for risk assessment is needed. The paper concludes that climate change and extreme weather events represent a real physical threat to the oil and gas sector, particularly in low-lying coastal areas and areas exposed to extreme weather events. The sector needs to take climate change seriously, assess its own vulnerability, and take appropriate measures to prevent or mitigate any potentially negative effects.

Description: As the impacts from anthropogenic climate change are increasing globally, people are experiencing dramatic shifts in weather, temperature, wildlife and vegetation patterns, and water and food quality and availability. These changes impact human health and well-being, and resultantly, climate change has been identified as the biggest global health threat of the 21st Century. Recently, research is beginning to indicate that changes in climate, and the subsequent disruption to the social, economic, and environmental determinants of health, may cause increased incidences and prevalence of mental health issues, emotional responses, and large-scale sociopsychological changes. Through a multi-year, community-led, exploratory case study conducted in Rigolet, Nunatsiavut, Labrador, Canada, this research qualitatively explores the impacts of climate change on mental health and well-being in an Inuit context. Drawing from 67 in-depth interviews conducted between January 2010 and October 2010 with community members and local and regional health professionals, participants reported that changes in weather, snow and ice stability and extent, and wildlife and vegetation patterns attributed to climate change were negatively impacting mental health and well-being due to disruptions in land-based activities and a loss of place-based solace and cultural identity. Participants reported that changes in climate and environment increased family stress, enhanced the possibility of increased drug and alcohol usage, amplified previous traumas and mental health stressors, and were implicated in increased potential for suicide ideation. While a preliminary case study, these exploratory findings indicate that climate change is becoming an additional mental health stressor for resource-dependent communities and provide a baseline for further research.

Description: Aims Afforestation causes important alterations in SOM content and composition that affect the soil functions and C balance. The aim of this study was to identify the mechanisms that determine the changes in SOM composition following afforestation of grasslands. Methods The study included 4 chronosequences and 5 paired plots comprising pastures and land afforested with Pinus radiata . The SOM was characterized by 13 C CP-MAS NMR spectroscopy and differential scanning calorimetry. Results During the first 10–20 year after afforestation, the changes in SOM content varied from slight gains to large losses (〉40 %). The analyses revealed that even SOM compounds considered resistant to decomposition were degraded during this time. The SOM gains, observed 20 year after stand establishment, were favoured by the higher recalcitrance of pine litter and possibly by soil acidification. The concentrations of most SOM compounds, particularly the stable compounds, were higher at the end of the rotation. The low degree of protection, along with the favourable climatic conditions, may also explain the rapid decomposition of SOM, including resistant compounds, in these soils. DSC analysis complemented the information about SOM composition provided by other techniques. Conclusions The accumulation of stable SOM compounds at the end of the rotation suggests a longer soil C turnover in these afforested soils, which may alleviate the gradual loss of SOC in intensively managed forest soils.

Description: Background and aims Plant nutrient uptake from coarse soil (2–4 mm diameter) has been demonstrated for only a limited number of nutrients, and the nutritional contribution of coarse soil when present with fine soil (material 〈2 mm diameter) in realistic ratios is unknown. We conducted a seedling pot trial to investigate the functional relevance of this soil fraction to plant nutrition. Methods Fine soil was mixed with either coarse soil, or the equivalent volume of inert glass chips, in ratios identical to those occurring naturally in soil sampled from two depths at each of two sites. Seedlings of Nothofagus solandri var. cliffortioides and Weinmannia racemosa were planted in the soil mixtures and harvested after 9 months. Results The content of nitrogen, phosphorous, potassium, magnesium and other elements in the above ground seedling tissue was significantly increased by the presence of coarse soil. The coarse soil fraction also contributed proportionally much more to plant nutrient uptake than fine soil on a mass per mass basis. Conclusions Coarse soil is excluded from conventional soil analysis, so is possible that soil nutrient capital is systematically underestimated. This has implications for land management and studies of plant dynamics in relation to nutrient supply.

Description: Background and aims Lateral tree-scale variability in plantations should be taken into account when scaling up from point samples, but appropriate methods for sampling and calculation have not been defined. Our aim was to define and evaluate such methods. Methods We evaluated several existing and new methods, using data for throughfall, root biomass and soil respiration in mature oil palm plantations with equilateral triangular spacing. Results Three ways of accounting for spatial variation within the repeating tree unit (a hexagon) were deduced. For visible patch patterns, patches can be delineated and sampled separately. For radial patterns, measurements can be made in radial transects or a triangular portion of the tree unit. For any type of pattern, including unknown patterns, a triangular sampling grid is appropriate. In the case studies examined, throughfall was 79 % of rainfall, with 95 % confidence limits being 62 and 96 % of rainfall. Root biomass and soil respiration, measured on a 35-point grid, varied by an order of magnitude. In zones with steep gradients in parameters, sampling density has a large influence on calculated mean values. Conclusions The methods defined here provide a basis for representative sampling and calculation procedures in studies requiring scaling up from point sampling, but more efficient methods are needed.

Description: Climate change related impacts, such as increased frequency and intensity of wildfires, higher temperatures, extreme changes to ecosystem processes, forest conversion and habitat degradation are threatening tribal access to valued resources. Climate change is and will affect the quantity and quality of resources tribes depend upon to perpetuate their cultures and livelihoods. Climate impacts on forests are expected to directly affect culturally important fungi, plant and animal species, in turn affecting tribal sovereignty, culture, and economy. This article examines the climate impacts on forests and the resulting effects on tribal cultures and resources. To understand potential adaptive strategies to climate change, the article also explores traditional ecological knowledge and historical tribal adaptive approaches in resource management, and contemporary examples of research and tribal practices related to forestry, invasive species, traditional use of fire and tribal-federal coordination on resource management projects. The article concludes by summarizing tribal adaptive strategies to climate change and considerations for strengthening the federal-tribal relationship to address climate change impacts to forests and tribal valued resources.

Description: Traditional knowledge is increasingly recognized as valuable for adaptation to climate change, bringing scientists and indigenous peoples together to collaborate and exchange knowledge. These partnerships can benefit both researchers and indigenous peoples through mutual learning and mutual knowledge generation. Despite these benefits, most descriptions focus on the social contexts of exchange. The implications of the multiple cultural, legal, risk-benefit and governance contexts of knowledge exchange have been less recognized. The failure to consider these contexts of knowledge exchange can result in the promotion of benefits while failing to adequately address adverse consequences. The purpose of this article is to promote awareness of these issues to encourage their wider incorporation into research, policy, measures to implement free, prior and informed consent (FPIC) and the development of equitable adaptation partnerships between indigenous peoples and researchers.

Description: We employ a single-country dynamically-recursive Computable General Equilibrium model to make health-focussed macroeconomic assessments of three contingent UK Greenhouse Gas (GHG) mitigation strategies, designed to achieve 2030 emission targets as suggested by the UK Committee on Climate Change. In contrast to previous assessment studies, our main focus is on health co-benefits additional to those from reduced local air pollution. We employ a conservative cost-effectiveness methodology with a zero net cost threshold. Our urban transport strategy (with cleaner vehicles and increased active travel) brings important health co-benefits and is likely to be strongly cost-effective; our food and agriculture strategy (based on abatement technologies and reduction in livestock production) brings worthwhile health co-benefits, but is unlikely to eliminate net costs unless new technological measures are included; our household energy efficiency strategy is likely to breakeven only over the long term after the investment programme has ceased (beyond our 20 year time horizon). We conclude that UK policy makers will, most likely, have to adopt elements which involve initial net societal costs in order to achieve future emission targets and longer-term benefits from GHG reduction. Cost-effectiveness of GHG strategies is likely to require technological mitigation interventions and/or demand-constraining interventions with important health co-benefits and other efficiency-enhancing policies that promote internalization of externalities. Health co-benefits can play a crucial role in bringing down net costs, but our results also suggest the need for adopting holistic assessment methodologies which give proper consideration to welfare-improving health co-benefits with potentially negative economic repercussions (such as increased longevity).

Description: Sensitivity to climate change and anthropogenic disturbance is a typical feature of Mediterranean forests, which grow under dynamic and manipulated environmental conditions. In this study, we examine stone pine ( Pinus pinea L.) along the Tyrrhenian coast of Italy to analyse the tree-growth variability on a temporal scale and to evaluate the radial growth response to climate trends over the last century. The analysis of tree ring widths at the decadal and multidecadal scale, which were standardised to remove the age trend, showed primarily significant downward trends and time periods with lower growth rates. Characterised by a clear decline in tree ring widths, the two periods of 20 years from the mid-1920s and the early 1970s appeared to be the least favourables for tree growth. Precipitation was the main factor driving growth, and the effect was cumulative over consecutive years because of the increase in soil water content. Including the current year of ring formation, correlations between decline in precipitation and tree growth were greatest with 3-year precipitation sums. The shifting influence of winter rainfall on tree ring growth toward not significant values during the last decades, together with the lack of significant correlation between the current year’s precipitation and growth decline from the 1970s, might suggest an increasingly dependence on long periods of water supply to utilise the water content stored due to the previous rainy years. The negative effect on tree-growth decline of summer and early-fall temperatures appeared as a forcing influence related to long-term changes in climate rather than high-frequency climate fluctuations.

Description: Background Plants must acquire at least 14 mineral nutrients from the soil to complete their life cycles. Insufficient availability or extreme high levels of the nutrients significantly affect plant growth and development. Plants have evolved a series of mechanisms to adapt to unsuitable growth conditions where nutrient levels are too low or too high. microRNAs (miRNAs), a class of small RNAs, are known to mediate post-transcriptional regulation by transcript cleavage or translational inhibition. Besides regulating plant growth and development, miRNAs are well documented to regulate plant adaptation to adverse environmental conditions including nutrient stresses. Scope In this review, we focus on recent progress in our understanding of how miRNAs are involved in plant response to stresses resulting from deficiency in nutrients, such as nitrogen, phosphorus, sulfur, copper and iron, as well as toxicities from heavy metal ions. Conclusions Accumulated evidence indicates that miRNAs play critical roles in sensing the abundance of nutrients, controlling nutrient uptake and phloem-mediated long-distance transport, and nutrient homeostasis. miRNAs act as systemic signals to coordinate these physiological activities helping plants respond to and survive nutrient stresses and toxicities. Knowledge about how miRNAs are involved in plant responses to nutrient stresses promise to provide novel strategies to develop crops with improved nutrient use efficiency which could be grown in soils with either excessive or insufficient availability of nutrients.

Description: Background and aims (i) compare the concentrations of total polyphenols (TP) and condensed tannins (CT), and CT profiles in different organs of mature trees and seedlings of eight true mangrove species in Hong Kong; (ii) examine the antioxidant activities of CT and (iii) relate the non-enzymatic antioxidative defence system with the vertical zonation pattern of mangrove species. Methods Mature trees and seedlings of eight species were collected from a Hong Kong mangrove swamp to determine TP and CT concentrations and the antioxidant activities of CT. Results According to TP concentrations, the true mangrove species could be broadly classified into three groups, (i) Lumnitzera racemosa and Aegiceras corniculatum 〉 (ii) Heritiera littoralis , Excoecaria agallocha , Bruguiera gymnorrhiza and Kandelia obovata 〉 (iii) Acanthus ilicifolius and Avicennia marina . The last two are pioneer species in the most foreshore location. They also had significantly lower antioxidant activities, CT concentrations and different CT profiles than the other six species in mid- and low-tides. Conclusions Classification of the eight true mangrove species into three groups based on polyphenols was similar to their vertical zonation from land to sea. The relationships between these antioxidants and zonation should be further verified by transplantation studies.

Description: Background and aims Soil phosphorus (P) indices that have been originally developed and applied to agricultural soils for predicting P uptake by plants were examined in a pot experiment to determine the most suitable index for P availability in bauxite-processing residue sand (BRS). Methods Pot trials with ryegrass were established using BRS that had been amended with various organic (greenwaste compost, biochar and biosolids) and inorganic (zeolite) materials and different levels of di-ammonium phosphate fertiliser. Soil P availability indices tested included anion-exchange membrane (AEM-P), 0.01 M calcium chloride (CaCl 2 -P), Colwell-P, and Mehlich 3-P. Results AEM-P was found to most closely reflect the available P status in BRS across all treatments, and had the strongest associations with plant P uptake compared to Colwell-P, Mehlich 3-P and CaCl 2 -P. AEM-P was more closely correlated with P uptake by ryegrass than other P indices, while Colwell-P was closely related to leaf dry matter. Interestingly, a strong inverse relationship between plant indices and pH in BRS growth media was observed, and an adequate level of plant P uptake was found only in 15 year-old rehabilitated BRS with pH 〈 8.0. Conclusions AEM-P was found to be the most suitable index for evaluating P availability in highly alkaline BRS and pH was an important parameter affecting uptake of P by ryegrass. Importantly, time is required (〉 5 years) before improved uptake of P by plants can be observed in rehabilitated residue sand embankments.

Description: Background & aims Herbivore-driven changes to soil properties can influence the decomposition rate of organic material and therefore soil carbon cycling within grassland ecosystems. We investigated how aboveground foraging mammalian and invertebrate herbivores affect mineral soil decomposition rates and associated soil properties in two subalpine vegetation types (short-grass and tall-grass) with different grazing histories. Methods Using exclosures with differing mesh sizes, we progressively excluded large, medium and small mammals and invertebrates from the two vegetation types in the Swiss National Park (SNP). Mineral soil decomposition rates were assessed using the cotton cloth (standard substrate) method between May and September 2010. Results Decomposition displayed strong spatio-temporal variability, best explained by soil temperature. Exclusion of large mammals increased decomposition rates, but further exclusion reduced decomposition rates again in the lightly grazed (tall-grass) vegetation. No difference among treatments was found in the heavily grazed (short-grass) vegetation. Heavily grazed areas had higher decomposition rates than the lightly grazed areas because of higher soil temperatures. Microbial biomass carbon and soil C:N ratio were also linked to spatio-temporal decomposition patterns, but not to grazing history. Conclusions Despite altering some of the environmental controls of decomposition, cellulose decomposition rates in the SNP’s subalpine grasslands appear to be mostly resistant to short-term herbivore exclusion.

Description: Climate change impact research needs regional climate scenarios of multiple meteorological variables. Those variables are available from regional climate models (RCMs), but affected by considerable biases. We evaluate the application of an empirical-statistical error correction method, quantile mapping (QM), for a small ensemble of RCMs and six meteorological variables. Annual and monthly biases are reduced to close to zero by QM for all variables in most cases. Exceptions are found, if non-stationarity of the model’s error characteristics occur. Even in the worst cases of non-stationarity, QM clearly improves the biases of raw RCMs. In addition, QM successfully adjusts the distributions of the analysed variables. To approach the question whether time series and inter-variable relationships are still plausible after correction, we evaluate the root-mean-square error (RMSE), autocorrelation and inter-variable correlation. We found improvement or no clear effect in RMSE and autocorrelation, and no clear effect on the correlation between meteorological variables. These results demonstrate that QM retains the quality of the temporal structure in time series and the inter-variable dependencies of RCMs. It has to be emphasised that this cannot be interpreted as an improvement and that deficiencies of the RCMs in those features are retained as well. Our results give some indication for the performance of QM applied to future scenarios, since our evaluation relies on independent calibration and evaluation periods, which are affected by climate variability and change. The effect of non-stationarity, however, can be expected to be larger in far future. We demonstrate the retainment of the RCM’s temporal structure and inter-variable dependencies, and large improvements in biases. This qualifies QM as a valuable, though not perfect, method in the interface between climate models and climate change impact research. Nonetheless, in case of no correlation between re-analysis driven RCM and observation, one should consider that QM does not correct this correlation.

Description: When is it time to adopt different technologies, management strategies, and resource use practices as underlying climate change occurs? We apply risk and decision analysis to test hypotheses about the timing and pace of adaption in response to different profiles of climate change and extremes expressed as yield and income variation for a simulated dryland wheat farm in the United States Great Plains. Climate scenarios include gradual change with typical or increased noise (standard deviation), rapid and large change, and gradual change with extreme events stepped through the simulation. We test decision strategies that might logically be utilized by farmers facing a climate trend that worsens crop enterprise outcomes. Adaptation quickens with the rate of change, especially for decision strategies based on performance thresholds, but is delayed by larger climate variability, especially for decision strategies based on recognizing growing differential between adaptive and non-adaptive performance. Extreme events evoke adaptation sooner than gradual change alone, and in some scenarios extremes evoke premature, inefficient, adaptation.

Description: Background Our recent publication (Warren et al., Plant Soil 366:683–693, 2013 ) described how pulses of deuterium oxide (D 2 O) or H 2 O combined with neutron radiography can be used to indicate root water uptake and hydraulic redistribution in maize. This technique depends on the large inherent differences in neutron cross-section between D and H atoms resulting in strong image contrast. Scope and Conclusions However, as illustrated by Carminati and Zarebanadkouki ( 2013 ) there can be a change in total water content without a change in contrast simply by a change in the relative proportions of D 2 O and H 2 O. We agree with their premise and detailed calculations (Zarebanadkouki at al. 2012 , 2013 ), and present further evidence that mixing of D 2 O and H 2 O did not confound evidence of hydraulic redistribution in our study.

Description: Background and aims The growth of green plants depends not only on photosynthesis, but also on the successful remobilization and translocation of seed phosphorus (P) reserves to the vegetative parts of the developing seedling during early growth. Remobilization and photosynthesis are therefore two parallel and co-coinciding processes involved in better seedling establishment and early growth. Methods A study was conducted to evaluate the priority of developing maize seedlings to translocate the remobilized seed P reserves and external P uptake to seedling root and shoot sinks during 4 weeks of early growth. Two fluxes of P in growing seedlings, one from seed remobilized P reserves and one from external P uptake, were distinguished by labelling external nutrient solution P with 32 P. Results The seedling phytomass was equally distributed between seedling roots and shoots for 530 cumulated degree days after sowing. Seedlings partitioned up to 71 % of P from seed reserves and up to 68 % of P acquired from the nutrient solution, to the shoots, depending on the seed P content and P concentration in the nutrient solution. It appears that accumulation of P slows down in seedling roots corresponds to the translocative functions of root P towards shoots for start of photosynthesis. Conclusions Our results suggest that the major part of seed P reserves and external P uptake were used in early development of the seedling and the preferred sink was seedling shoots.

Description: Background and aims Nickel (Ni) has become a major heavy metal contaminant. The form of nitrogen nutrition remarkably affects IRT1 expression in roots. IRT1 has an activity of transporting Ni 2+ into root cells. Therefore, nitrogen-form may affect Ni accumulation and toxicity in plants. The assumption was investigated in this study. Methods The Arabidopsis plants were treated in Ni-contained growth solutions with either nitrate (NO 3 − ) or ammonium (NH 4 + ) as the sole N source. After 7-day treatments, Ni concentration, IRT1 expression, Ni-induced toxic symptoms and oxidative stress in plants were analyzed. Results The NO 3 − -fed plants contained a higher Ni concentration, had a greater IRT1 expression in roots, and developed more severe toxic symptoms in the youngest fully expanded leaves, compared with the NH 4 + -fed plants. The Ni-induced growth inhibition was also more significant in NO 3 − -fed plants. Interestingly, Ni exposure resulted in greater hydrogen peroxide (H 2 O 2 ) and superoxide radical (O 2 . − ) accumulations, more severe lipid peroxidation and more cell death in NO 3 − -fed plants, whereas the opposite was true for NH 4 + -fed plants. Furthermore, the Ni-enhanced peroxidase (POD) and superoxide dismutase (SOD) activities were greater in NO 3 − -fed plants Conclusion NO 3 − nutrition promotes Ni uptake, and enhances Ni-induced growth inhibition and oxidative stress in plants compared with NH 4 + nutrition.

Description: Background and aims Brassica napus has high boron (B) demand, but significant genotype differences exist with respect to B deficiency. The aim of this research was to elucidate the relationship between the different sensitivities of Brassica napus cultivars to low B stress and the characteristics of B uptake and transport to characterise the regulation of B efficiency in Brassica napus . Methods B-efficient and B-inefficient Brassica napus cultivars were used to compare the uptake and transport of B using the stable isotope 10 B tracer and grafting experiments, as well as expression of B transporters by RT-PCR. Results B-efficient cultivars have significant advantages with regard to B limitation. The B-efficient cultivar HZ showed less severe B deficiency symptoms and higher dry biomass than the B-inefficient cultivars LW and LB. Both the amount of total B and the 10 B concentration and accumulation in the shoots and roots of B-efficient HZ were higher than those of B-inefficient cultivars. In B-inefficient LW, the amount of total B and the 10 B that was transported into shoots was less than in the other three cultivars and the content and accumulation of total B and 10 B in the roots of B-inefficient LB were the lowest among all of the cultivars. When the roots of B-efficient HZ were used as stocks, the grafted plants showed B-efficient characteristics, such as mild B deficiency symptoms, and higher dry biomass and B accumulation, regardless of whether they originated from B-efficient or B-inefficient cultivars. In contrast, the grafted plants with B-inefficient LW used as stocks were B-inefficient. The expressions of BnBOR1;1c , BnBOR1;2a and BnNIP5;1 were up-regulated in roots under low B stress compared with the normal B condition. However, there was no obvious difference in the expressions of the three genes or of four other BnBOR1s between B-efficient and B-inefficient cultivars in low or normal B environments. Conclusions These results indicate that the B efficiency of Brassica napus is controlled primarily by roots, which allow more uptake and accumulation of B in B-efficient cultivars than B-inefficient cultivars in a low B environment. However the molecular mechanism regulating B efficiency in Brassica napus remains to be determined.

Description: Aims Application of carbon (C) and nitrogen (N) isotopes is an essential tool to study C and N flows in plant-soil-microorganisms systems. When targeting single plants in a community the tracers need to be added via e.g., leaf-labeling or stem-feeding approaches. In this study we: (i) investigated if bicarbonate can be used to introduce 14 C (or 13 C) into white clover and ryegrass, and (ii) compared the patterns of 14 C and 15 N allocation in white clover and ryegrass to evaluate the homogeneity of tracer distribution after two alternative labeling approaches. Methods Perennial ryegrass and white clover were pulse labeled with 15 N urea via leaf-labeling and 14 C either via a 14 CO 2 atm or with 14 C bicarbonate through leaf-labeling. Plants were sampled 4 days after labeling and prepared for bulk isotope analysis and for 14 C imaging to identify plant parts with high and low 14 C activity. Subsequently, plant parts with high and low 14 C activity were separated and analyzed for 15 N enrichment. Results Bicarbonate applied by leaf-labeling efficiently introduced 14 C into both white clover and ryegrass, although the 14 C activity in particular for white clover was found predominantly in the labeled leaf. Using 14 C imaging for identification of areas with high (hotspots) and low 14 C activity showed that 14 C was incorporated very heterogeneously both when using bicarbonate and CO 2 as expected when using pulse labeling. Subsequent analysis of 15 N enrichment in plant parts with high and low 14 C activity showed that 15 N also had a heterogeneous distribution (up to two orders of magnitude). Conclusion Bicarbonate can efficiently be used to introduce 14 C or 13 C into plant via the leaf-labeling method. Both 14 C and 15 N showed heterogeneous distribution in the plant, although the distribution of 15 N was more even than that of 14 C.

Description: Background and aim In numerous areas, rice cultivated under flooded conditions is exposed simultaneously to iron excess and arsenic contamination. The impact of these combined stresses on yield-related parameters and As distribution and speciation in various plant parts remains poorly documented. Methods Rice (cv I Kong Pao) was exposed to iron excess (125 mg L −1 Fe 2 SO 4 ), arsenic (50 and 100 μM Na 2 HAsO 4 .7H 2 O) or a combination of those stressing agents in hydroponic culture until harvest. Plant growth, yield-related parameters, non protein thiols concentration and mineral nutrition were studied in roots and shoots. Arsenic speciation was determined by high-performance liquid chromatography-hydride generation-atomic fluorescence spectrometry. Key Results Iron excess increased As retention by the roots in relation to the development of the root iron plaque but decreased As accumulation in the shoot. Arsenic concentration was lower in the grains than in the shoots. Iron stress reduced As accumulation in the husk but not in the dehusked grains. Iron excess decreased the proportion of extractable As(III) and As(V) in the grain while it increased the proportion of extractable As(III) in the shoot. Combined stresses (Fe+As) affected plant nutrition and significantly reduced the plant yield by limiting the number of grains per plant and the grain filling. Conclusions Fe excess had an antagonist impact on shoot As concentration but an additive negative impact on several yield-related parameters. Iron stress influences both As distribution and As speciation in rice.

Description: Background and aims Intermittently frozen ground in winter is expected to disappear over large areas in the temperate zone due to ongoing climate warming. The lack of soil frost influences plant soil interactions and needs to be studied in more detail. Methods Winter soil frost was avoided by belowground heating wires in a field experiment over two subsequent winters in a temperate grassland. Soil respiration, soil nitrogen availability and plant performance (aboveground biomass, root length at two depth levels, greenness, nutrient content) were compared between “no-frost” and reference plots which underwent repeated freeze-thaw cycles in both winters. Results Soil respiration increased in the “no-frost” treatment during the warming phase (+291 %). N-availability in the upper 10 cm of the soil profile was not affected, possibly due to increased plant N accumulation during winter (+163 %), increased plant N concentration (+18 %) and increased biomass production (+31.5 %) in the growing season. Translocation of roots into deeper soil layers without changes in total root length in response to the “no-frost” treatment, however, may be a sign of nutrient leaching. Conclusions The cumulative effect on carbon cycling due to warmer soils therefore depends on the balance between increased winter carbon loss due to higher soil biotic activity and enhanced plant productivity with higher nutrient accumulation in the growing season.

Description: Aims The aims of this work were to investigate the aluminum (Al) and phosphate (P) interactions in the regulation of root system architecture of Arabidopsis thaliana seedlings and the contribution of auxin signaling in primary and lateral root growth in response to Al toxicity. Methods Detailed analyses of root system architecture and cell division were performed in Arabidopsis WT seedlings and in low phosphorus insensitive mutants lpi1 - 3 and lpr1 - 1 lpr2 - 1 in response to Al. Expression studies of P-deficiency regulated phosphate transporter AtPT2 were also conducted. The role of auxin as a mediator of root morphogenetic changes by Al was evaluated by using the auxin-signaling mutants tir1 , tir1 afb2 afb3 , and arf7 arf19 . Results Al inhibited primary root growth by affecting cell cycle progression and causing differentiation of cells in the root meristem. These effects were reduced in low phosphorus insensitive lpi1 - 3 and low phosphate resistant lpr1 - 1 lpr2 - 1 Arabidopsis mutants. Al also activated the expression of the low phosphate-induced P transporter AtPT2 in roots. Lateral root formation by Al decreased in tir1 afb2 afb3 while arf7 arf19 mutants were highly resistant to Al in both primary root inhibition and lateral root induction. Conclusions Our results suggest that lateral root formation in response to Al toxicity and P deficiency may involve common signaling mechanisms, while a pathway involving ARF7 and ARF19 is important for primary root growth inhibition by Al.

Description: Aims Litter decomposition and subsequent nutrient release play a major role in forest carbon and nutrient cycling. To elucidate how soluble or bulk nutrient ratios affect the decomposition process of beech ( Fagus sylvatica L.) litter, we conducted a microcosm experiment over an 8 week period. Specifically, we investigated leaf-litter from four Austrian forested sites, which varied in elemental composition (C:N:P ratio). Our aim was to gain a mechanistic understanding of early decomposition processes and to determine microbial community changes. Methods We measured initial litter chemistry, microbial activity in terms of respiration (CO 2 ), litter mass loss, microbial biomass C and N (C mic and N mic ), non purgeable organic carbon (NPOC), total dissolved nitrogen (TDN), NH 4 + , NO 3 - and microbial community composition (phospholipid fatty acids – PLFAs). Results At the beginning of the experiment microbial biomass increased and pools of inorganic nitrogen (N) decreased, followed by an increase in fungal PLFAs. Sites higher in NPOC:TDN (C:N of non purgeable organic C and total dissolved N), K and Mn showed higher respiration. Conclusions The C:N ratio of the dissolved pool, rather than the quantity of N, was the major driver of decomposition rates. We saw dynamic changes in the microbial community from the beginning through the termination of the experiment.

Description: Background and aims Grazing may influence nutrient cycling in several ways. In productive mountain grasslands of central Argentina cattle grazing maintain a mosaic of different vegetation patches: lawns, grazed intensively and dominated by high quality palatable plants, and open and closed tussock grasslands dominated by less palatable species. We investigated if differences in the resources deposited on soil (litter and faeces) were associated with litter decomposition rates and soil nitrogen (N) availability across these vegetation patches. Methods We compared the three vegetation patches in terms of litter and faeces quality and decomposability, annual litterfall and faeces deposition rate. We determined decomposition rates of litter and faces in situ and decomposability of the same substrates in a common garden using “litter bags”. We determined soil N availability (with resin bags) in the vegetation patches. Also, we performed a common plant substrates decomposition experiment to assess the effect of soil environment on decomposition process. This technique provides important insights about the soil environmental controls of decomposition (i.e. the sum of soil physicochemical and biological properties, and microclimate), excluding the substrate quality. Results The litter quality and faeces deposition rate were higher in grazing lawns, but the total amounts of carbon (C) and nitrogen (N) deposited on soil were higher in tussock grasslands, due to higher litterfall in these patches. The in situ decomposition rates of litter and faeces, and of the two common plant substrates were not clearly related to either grazing pressure, litterfall or litter quality (C, N, P, lignin, cellulose or hemicellulose content). In situ litter decomposition rate and soil ammonium availability were correlated with the decomposition rates of both common plant substrates. This may suggest that difference in local soil environment among patch types is a stronger driver of decomposition rate than quality or quantity of the resource that enter the soil. Conclusions Our results show that, although high grazing pressure improves litter quality and increases faeces input, the reduction in biomass caused by herbivores greatly reduces C and N input for the litter decomposition pathway. We did not find an accelerated decomposition rate in grazing lawns as proposed by general models. Our results point to soil environment as a potential important control that could mask the effect of litter quality on field decomposition rates at local scale.

Description: Background and aims Cd uptake has been shown to increase during conditions of Fe deficiency. This study tested the hypothesis that Fe-deficiency-responsive genes, particularly OsNRAMP1, play a role in the increased Cd uptake that occurs when rice is grown in aerobic soil conditions. Methods Plants were grown in aerobic or flooded soil conditions. Uptake of Cd was compared to levels of expression of candidate metal transporters and to metal ion availability in soil. Results Plants grown with intermittent soil flooding experienced a predominantly aerobic root environment and had the highest plant Cd uptake. Stronger upregulation of OsNRAMP1 was detected in plants grown in unflooded soil than in flooded soil. However, these transcriptional responses were not linked to an increase in Cd uptake. Overexpression of OsNRAMP1 was not found to increase the uptake of Cd in rice in soil or solution culture. In contrast, there were large differences in availability of Cd, Fe and Mn between flooded and aerobic soils, which were linked to changes in Cd uptake. Conclusions Aerobic soil conditions favour Cd uptake through increased Cd availability and decreased competition between Cd and Fe rather than through the increased expression of the Fe transporters themselves.

Description: Background and aims Intensive land use has led to degradation and abandonment of Portuguese oak woodlands, and subsequent shrub encroachment may have altered the spatial heterogeneity of soil C and N pools. The aim of this study was to evaluate the effects of shrub invasion on soil C and N dynamics in an oak woodland in Southern Portugal. Methods Soil was sampled beneath and outside scattered Quercus suber L. canopies, considering non-encroached areas and areas encroached by shrubs ( Cistus ladanifer L. or Cistus salviifolius L.). Results The spatial heterogeneity of soil C and N contents was mainly associated with tree presence. Outside tree canopies, the labile C pools were larger (mainly beneath C . ladanifer ) and C cycling was faster in encroached areas than in non-encroached areas. Net and gross N mineralization and urease and protease activities were also higher in encroached than in non-encroached areas; however, the metabolic quotient and the Cmicrobial/Corganic ratio were not significantly affected. Beneath the tree canopy, significant effects of encroachment included a small increase in soil labile C and the enzymatic activity beneath C . ladanifer . Conclusions The results indicate the potential capacity of shrub encroachment to accumulate soil organic C in the long term. The rate of soil C and N turnover promoted by shrub encroachment may depend on the Cistus species present.

Description: Aims Decreased expression of TaNAM genes by RNAi results in delayed senescence and decreased grain protein, iron, and zinc concentrations. Here, we determined whether NAM expression level alters onset of senescence under stress conditions, whether delayed senescence in the TaNAM -RNAi line resulted in improved tolerance to post-anthesis abiotic stress, and determined the effects of post-anthesis abiotic stress on N and mineral remobilization and partitioning to grain. Methods Greenhouse-grown WT and TaNAM -RNAi wheat were characterized in two studies:three levels of N fertility or water limitation during grain fill. Studies were conducted under both optimal and heat stress temperatures. Senescence onset was determined by monitoring flag leaf chlorophyll. Results Under optimal tempertures, TaNAM -RNAi plants had a yield advantage at lower N. TaNAM -RNAi plants had delayed senescence relative to the WT and lower grain protein and mineral concentrations, N remobilization efficiency, and partitioning of N and most minerals to grain. Conclusions Nutritional quality of TaNAM -RNAi grain was consistently lower than WT. Delayed senescence of TaNAM -RNAi plants provided a yield advantage under optimal temperatures but not under water or heat stress. Discovery of specific NAM protein targets may allow separation of the delayed senescence and nutrient partitioning traits, which could be used for improvement of wheat.

Description: Aims Nitrification inhibitors (NI) formulated on granulated ammonium sulphate nitrate (ASN) are an option to minimize nitrate leaching into ground waters and emissions of the greenhouse gas N 2 O. This paper focuses (a) on the development of an analytic enabling to extract and quantify the NI 3,4-dimethylpyrazolephosphate (DMPP), marketed since 1999. The efficiency of DMPP has been studied in laboratory and field soils. Here the DMPP analytic and the behaviour of a nitrifying bacterial consortium enriched from a field soil and exposed to zero, field applied and a 10 fold higher DMPP concentration than the recommended one for field application are in the focus. Methods For extracting DMPP quantitatively from soils a method connected to a HPLC analytic has been developed by us and was standardized in laboratory experiment with a silt clay field soil (allochtone Vega). The method is detailed described here. Its reliability has been tested in a 3 years field trial under varying cropping systems and climatic conditions asides the influence of DMPP on CO 2 −, CH 4 − and N 2 O- emissions, measured by the closed chamber method. Parallel a nitrifying bacterial consortium of the silty clay field soil was enriched and subjected to 0, the recommended DMPP concentration for field applications and a 10 times higher one. In incubation experiments the conversion of ammonium to nitrite and nitrate in presence and absence of DMPP was spectrophotometer determined and pH-shifts with a scaled litmus paper. In sacrificed flasks at the end of incubation morphological changes of the bacteria involved were studied by transmission electron microscope (TEM). Results The ammonium, nitrite and nitrate determinations and the TEM pictures show that in presence of the field applied DMPP concentration the nitrifying activity returned around 30 days later than in the control and the cells were slightly enlarged. In presence of a 10 times higher DMPP concentration a recovery was prevented. DMPP prolongs, compared with dicyandiamide (DCD), the period of nitrifiers’ inhibition and reduced N 2 O− and CO 2 − the emissions (Weiske et al., Biol Fertil Soils 34:109–117, 2001a , Nutr Cycl Agroecosys 60:57–64, b ). Conclusions With the method developed by us the stability of DMPP in agricultural soils can be satisfyingly and reproducible studied down to a detection limit of 0.01 μg DMPP g −1 dry soil. The morphological changes in the nitrifying consortium due to DMPP concentrations are in agreement with the recovery rate found by nitrite and nitrate formation.

Description: Background and aims Adequate zinc (Zn) in maize ( Zea mays L.) is required for obtaining Zn-enriched grain and optimum yield. This study investigated the impact of varying Zn fertilizer placements on Zn accumulation in maize plant. Methods Two pot experiments with same design were conducted to investigate the effect of soil Zn heterogeneity by mixing ZnSO 4 ·7H 2 O (10 mg Zn kg −1 soil on an average) in 10–15, 0–15, 25–30, 0–30, 30–60 and 0–60 cm soil layers on maize root growth and shoot Zn content at flowering stage in experiment-1, and assessing effects on grain Zn accumulation at mature stage in experiment-2. Results In experiment-1, Zn placements created a large variation in soil DTPA-Zn concentration (0.3–29.0 mg kg −1 ), which induced a systemic and positive response of root growth within soil layers of 0–30 cm; and shoot Zn content was increased by 102 %–305 % depending on Zn placements. Supply capacity of Zn in soil, defined as sum of product of soil DTPA-Zn concentration and root surface area at different soil layers, was most related to shoot Zn content ( r  = 0.82, P  〈 0.001) via direct and indirect effects according to path analysis. In experiment-2, Zn placements increased grain Zn concentration by up to 51 %, but significantly reduced the grain Zn harvest index from 50 % by control to about 30 % in average. Conclusion Matching the distribution of soil applied Zn with root by Zn placement was helpful to maximize shoot Zn content and grain Zn concentration in maize.

Description: Background and Aims Wetting-drying cycles are important environmental processes known to enhance aggregation. However, very little attention has been given to drying as a process that transports mucilage to inter-particle contacts where it is deposited and serves as binding glue. The objective of this study was to formulate and test conceptual and mathematical models that describe the role of drying in soil aggregation through transportation and deposition of binding agents. Methods We used an ESEM to visualize aggregate formation of pair of glass beads. To test our model, we subjected three different sizes of sand to multiple wetting-drying cycles of PGA solution as a mimic of root exudates to form artificial aggregates. Water stable aggregate was determined using wet sieving apparatus. Results A model to predict aggregate stability in presence of organic matter was developed, where aggregate stability depends on soil texture as well as the strength, density and mass fraction of organic matter, which was confirmed experimentally. The ESEM images emphasize the role of wetting-drying cycles on soil aggregate formation. Conclusions Our experimental results confirmed the mathematical model predictions as well as the ESEM images on the role of drying in soil aggregation as an agent for transport and deposition of binding agents.

Description: Background and aims Many plant growth-promoting endophytes (PGPE) possessing 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity can reduce the level of stress ethylene and assist their host plants cope with various biotic and abiotic stresses. However, information about the endophytic bacteria colonizing in the coastal halophytes is still very scarce. This study aims at isolating efficient ACC deaminase-producing plant growth-promoting (PGP) bacterial strains from the inner tissues of a traditional Chinese folk medicine Limonium sinense (Girard) Kuntze, a halophyte which has high economic and medicinal values grown in the coastal saline soils. Their PGP activity and effects on host seed germination and seedling growth under salinity stress were also evaluated. Methods A total of 126 isolates were obtained from the surface sterilized roots, stems and leaves of L. sinense (Girard) Kuntze. They were initially selected for their ability to produce ACC deaminase as well as other PGP properties such as production of indole-3-acetic acid (IAA), N 2 -fixation, and phosphate-solubilizing activities and subsequently identified by the 16S rRNA gene sequencing. For selected strains, seed germination, seedling growth, and flavonoids production in axenically growth L. sinense (Girard) Kuntze seedlings at different NaCl concentrations (0–500 mM) were quantified. Results Thirteen isolates possessing ACC deaminase activity were obtained. The 16S rRNA gene sequencing analysis showed them to belong to eight genera: Bacillus , Pseudomonas , Klebsiella , Serratia , Arthrobacter , Streptomyces , Isoptericola , and Microbacterium . Inoculation with four of the selected ACC deaminase-producing strains not only stimulated the growth of the host plant but also influenced the flavonoids accumulation. All four strains could colonize and can be re-isolated from the host plant interior tissues. Conclusions These results demonstrate that ACC deaminase-producing habitat-adapted symbiotic bacteria isolated from halophyte could enhance plant growth under saline stress conditions and the PGPE strains could be appropriate as bioinoculants to enhance soil fertility and protect the plants against salt stress.

Description: Climate change is likely to increase the frequency and intensity of water-related hazards on human populations. This has generated security concerns and calls for urgent policy action. However, the simplified narrative that links climate change to security via water and violent conflict is wanting. First, it is not confirmed by empirical evidence. Second, it ignores the varied character and implications of hydro-climatic hazards, the multi-faceted nature of conflict and adaptive action, and crucial intricacies of security. Integrating for the first time research and findings from diverse disciplines, we provide a more nuanced picture of the climate-water-security nexus. We consider findings from the transboundary waters, armed conflict, vulnerability, and political ecology literatures and specify the implications and priorities for policy relevant research. Although the social effects of future hydro-climatic change cannot be safely predicted, there is a good understanding of the factors that aggravate risks to social wellbeing. To reduce vulnerability, pertinent democratic and social/civil security institutions should be strengthened where they exist, and promoted where they are still absent.

Description: Most discussions of impacts of Climate Change have focused on species from temperate or polar regions. Impacts to species inhabiting warm climates are often believed to be small relative to those of species living in cooler climates. However, it is evident that some tropical/sub-tropical species, including some marine megafauna may face potentially serious consequences from a changing climate. For example, larger, warmer oceans may appear to benefit marine wildlife species like cold-sensitive Florida manatees; however, findings regarding the impact of global climate change (GCC) on estuaries and nearshore areas of Florida indicate that predicted impacts of climate change may be detrimental to endangered manatees. An examination of how projected impacts of climate change will affect threats to manatees and their habitat indicates that threats may be exacerbated. The most significant threats to the Florida manatee population, such as cold-stress, watercraft collisions, and harmful algal blooms likely will increase. Habitat is likely to be degraded under future climate scenarios. Alterations to Florida’s marine environment are ongoing, yet current manatee management plans do not consider the impacts of climate change. The ability of manatees to adapt to change will be influenced by the speed of change and the degree to which human activity impedes or alters it. To minimize impacts to species we must recognize the influence GCC may have on populations, and begin to identify and implement ways to slow or reverse negative impacts arising from it.

Description: Due to complexities of creating sea-level rise scenarios, impacts of climate-induced sea-level rise are often produced from a limited number of models assuming a global uniform rise in sea level. A greater number of models, including those with a pattern reflecting regional variations would help to assure reliability and a range of projections, indicating where models agree and disagree. This paper determines how nine new patterned-scaled sea-level rise scenarios (plus the uniform and patterned ensemble mean rises) influence global and regional coastal impacts (wetland loss, dry land loss due to erosion and the expected number of people flooded per year by extreme sea levels). The DIVA coastal impacts model was used under an A1B scenario, and assumed defences were not upgraded as conditions evolved. For seven out of nine climate models, impacts occurred at a proportional rate to global sea-level rise. For the remaining two models, higher than average rise in sea level was projected in northern latitudes or around populated coasts thus skewing global impact projections compared with the ensemble global mean. Regional variability in impacts were compared using the ensemble mean uniform and patterned scenarios: The largest relative difference in impacts occurred around the Mediterranean coast, and the largest absolute differences around low-lying populated coasts, such as south, south-east and east Asia. Uniform projections of sea-level rise impacts remain a useful method to determine global impacts, but improved regional scale models of sea-level rise, particularly around semi-enclosed seas and densely populated low-lying coasts will provide improved regional impact projections and a characterisation of their uncertainties.

Description: Shared Socioeconomic Pathways (SSPs) describe alternative outcomes for socioeconomic development. Papers describing the conceptual framework for SSPs refer to challenges to mitigation and to adaptation as fundamental concepts. Identifying which socioeconomic factors are the most important determinants of these challenges, and how to combine them in an internally consistent manner, is critical to scenario design. Here we demonstrate a systematic and traceable approach for identifying and prioritizing scenario elements. In this study, we identify 13 determinants of mitigation and adaptation challenges at a globally aggregated scale based on a survey of 25 experts. In addition, we use 19 expert elicitations and a cross-impact balance analysis to create approximately 1.5 million combinations of trends for these determinants and rank them in terms of internal consistency. Using the 1,000 most consistent combinations, we construct composite metrics for challenges to mitigation and adaptation to uncover distinguishable characteristics for five types of SSPs: those with Low, Medium, and High challenges to both mitigation and adaptation (consistent with SSPs 1–3), and those in which adaptation challenges or mitigation challenges dominate (consistent with SSPs 4–5). We find a distinguishing characteristic for mixed typology SSP4 (low mitigation challenges, high adaptation challenges): High trends for innovation capacity could lower challenges to mitigation but not necessarily challenges to adaptation. We also find that a low trend for quality of governance consistently corresponds to higher challenges to adaptation. These findings are suggestive for future research on the SSPs in particular, while our analytical approach is instructive for scenario development in general.

Description: Politicians who proclaim both their skepticism about global warming and their conservative religious credentials leave the impression that conservative Protestants may be more skeptical about scientists’ claims regarding global warming than others. The history of the relationship between conservative Protestantism and science on issues such as evolution also suggests that there may be increased skepticism. Analyzing the 2006 and 2010 General Social Survey, we find no evidence that conservative Protestantism leads respondents to have less belief in the conclusiveness of climate scientists’ claims. However, a second type of skepticism of climate scientists is an unwillingness to follow scientists’ public policy recommendations. We find that conservative Protestantism does lead to being less likely to want environmental scientists to influence the public policy debate about what to do about climate change. Existing sociological research on the relationship between religion and science suggests that this stance is due to a long-standing social/moral competition between conservative Protestantism and science.

Description: This paper describes the scenario matrix architecture that underlies a framework for developing new scenarios for climate change research. The matrix architecture facilitates addressing key questions related to current climate research and policy-making: identifying the effectiveness of different adaptation and mitigation strategies (in terms of their costs, risks and other consequences) and the possible trade-offs and synergies. The two main axes of the matrix are: 1) the level of radiative forcing of the climate system (as characterised by the representative concentration pathways) and 2) a set of alternative plausible trajectories of future global development (described as shared socio-economic pathways). The matrix can be used to guide scenario development at different scales. It can also be used as a heuristic tool for classifying new and existing scenarios for assessment. Key elements of the architecture, in particular the shared socio-economic pathways and shared policy assumptions (devices for incorporating explicit mitigation and adaptation policies), are elaborated in other papers in this special issue.

Description: Aims The objective of this study was to investigate the effects of future warming and drought on (1) the biochemical composition of above-ground biomass of forage plants ( Festuca arundinacea and Dactylis glomerata ), (2) the potential mineralization of this material in soil, and (3) its priming effect on native soil organic matter. Methods We sampled above-ground plant material from spring regrowth and summer regrowth of a climate change experiment. While in spring, the plants were well watered, the summer regrowth was exposed to drought and elevated temperature (+3 °C) by infrared heating of the canopy during 3 weeks. We assessed the elemental and isotopic composition, lignin and non-cellulosic carbohydrate content and composition of plant material grown under all three conditions. Its mineralization potential in soil and priming effects were evaluated during laboratory incubation. Results Warming had no significant effect on elemental and stable isotope composition of both plant materials. In contrast, it resulted in reduction of lignin content for both plant species and decrease of the lignin-to-N ratio for F. arundinacea and increased non-cellulosic carbohydrate content for D. glomerata . Summer regrowth was characterised by increase of δ 13 C values, which is consistent with variations in stomatal conductance due to water shortage. Moreover, summer drought induced an increase in N content leading to decrease of the C/N ratio and increase of lignin-to-N ratio of summer regrowth compared to spring regrowth. Differences in decomposition were small, while priming effects were more strongly altered by the different exposure to enviromental. Conclusion Our results provide direct experimental evidence that extreme climatic events (high temperature and precipitation deficit) have an influence on soil carbon storage particularly through their effect on priming of native soil organic matter induced by altered plant litter. These effects seem to be governed by alterations of stoichiometry and to a smaller extent by alterations of plant chemical composition.

Description: Background and aim Saccharothrix algeriensis NRRL B-24137, isolated from a Saharan soil, has been described as a potential biocontrol agent against Botrytis cinerea and other phytopathogens. However, the plant protection mechanisms involved still need to be described. The aim of this study was to determine this protection phenomenon as well as parts of the mechanisms involved, using Arabidopsis thaliana seedlings and B. cinerea . Methods The bacterial colonization process was evaluated on A. thaliana seedlings using fluorescence in situ hybridization. Protection of A. thaliana seedlings inoculated with NRRL B-24137 against B. cinerea was then evaluated. Parts of the mechanisms involved in the systemic protection against B. cinerea were evaluated using known mutants of genes involved in jasmonate (JA)/ethylene (ET)/salicylic acid (SA) signaling. Other Arabidopsis mutants, AtrhbohD-3 , AtrhbohF-3 , and ups1-1 were also screened to determine other parts of the mechanisms involved. Results The results showed that the strain NRRL B-24137 colonized, epi- and endophytically, the roots of Arabidopsis seedlings but the strain was not a systemic colonizer during the time of the experiment. The strain NRRL B-24137 also reduced B. cinerea symptoms and the protection was linked to known mechanisms of induced systemic resistance (ISR; JA/ET signaling), as well as to functionality of AtrbohF oxidase and of UPS1. Crosstalk between ET/JA and SA signaling could also be involved. Conclusions The isolate NRRL B-24137, after colonizing the root systems of A. thaliana , induces an ISR against B. cinerea , which is JA/ET dependent, but could also require SA crosstalk and protection could also require NAPDH oxidases and UPS1 functionalities.

Description: American Indian and Alaska Native tribes are uniquely affected by climate change. Indigenous peoples have depended on a wide variety of native fungi, plant and animal species for food, medicine, ceremonies, community and economic health for countless generations. Climate change stands to impact the species and ecosystems that constitute tribal traditional foods that are vital to tribal culture, economy and traditional ways of life. This paper examines the impacts of climate change on tribal traditional foods by providing cultural context for the importance of traditional foods to tribal culture, recognizing that tribal access to traditional food resources is strongly influenced by the legal and regulatory relationship with the federal government, and examining the multi-faceted relationship that tribes have with places, ecological processes and species. Tribal participation in local, regional and national climate change adaption strategies, with a focus on food-based resources, can inform and strengthen the ability of both tribes and other governmental resource managers to address and adapt to climate change impacts.

Description: Despite a keen awareness of climate change, northern Indigenous Peoples have had limited participation in climate-change science due to limited access, power imbalances, and differences in worldview. A western science emphasis on facts and an indigenous emphasis on relationships to spiritual and biophysical components indicate important but distinct contributions that each knowledge system can make. Indigenous communities are experiencing widespread thawing of permafrost and coastal erosion exacerbated by loss of protective sea ice. These climate-induced changes threaten village infrastructure, water supplies, health, and safety. Climate-induced habitat changes associated with loss of sea ice and with landscape drying and extensive wildfires interact with northern development to bring both economic opportunities and environmental impacts. A multi-pronged approach to broadening indigenous participation in climate-change research should: 1) engage communities in designing climate-change solutions; 2) create an environment of mutual respect for multiple ways of knowing; 3) directly assist communities in achieving their adaptation goals; 4) promote partnerships that foster effective climate solutions from both western and indigenous perspectives; and 5) foster regional and international networking to share climate solutions.

Description: A reliable public electricity supply depends in part on a reliable electricity grid system to transmit and distribute electrical power from generating stations to consumers. The grid system comprises many components that are exposed to the weather and can experience faults as a result of weather events. As climate change is expected to alter the number and severity of weather events, then the reliability of the grid and hence the reliability of electricity supplies can be affected. This paper reviews the effects of weather events on grid systems, illustrated by reference to experience on the grid systems in Europe and North America. It is shown that the effects on the high voltage transmission networks are different from the effects on lower voltage distribution networks and that generally the most significant extreme weather is high winds. Some remedial measures that can mitigate the effects of weather events are also described.

Description: Extreme weather events and changed climate parameters have impacts on power plants and their connected infrastructures. Therefore, adaptation, especially in the context of a changing climate and a resulting shift in the intensity and frequency of extreme events, is necessary. Thermal power plants are subject to a diversity of extreme weather impacts, making them vulnerable if not adapted. In this paper, the impacts of extreme weather events on thermal power plants are first identified and structured. Then selected adaptation options for thermal power plants are presented. Three major types of adaptation option are identified: adaptation of cooling, infrastructure, and sites. The Supplementary Material introduces a GIS-based (Geographic Information System) decision-support tool for power plant adaptation and planning.

Description: American Indians have unique vulnerabilities to the impacts of climate change because of the links among ecosystems, cultural practices, and public health, but also as a result of limited resources available to address infrastructure needs. On the Crow Reservation in south-central Montana, a Northern Plains American Indian Reservation, there are community concerns about the consequences of climate change impacts for community health and local ecosystems. Observations made by Tribal Elders about decreasing annual snowfall and milder winter temperatures over the 20th century initiated an investigation of local climate and hydrologic data by the Tribal College. The resulting analysis of meteorological data confirmed the decline in annual snowfall and an increase in frost free days. In addition, the data show a shift in precipitation from winter to early spring. The number of days exceeding 90 ˚F (32 ˚C) has doubled in the past century. Streamflow data show a long-term trend of declining discharge. Elders noted that the changes are affecting fish distribution within local streams and plant species which provide subsistence foods. Concerns about warmer summer temperatures also include heat exposure during outdoor ceremonies that involve days of fasting without food or water. Additional community concerns about the effects of climate change include increasing flood frequency and fire severity, as well as declining water quality. The authors call for local research to understand and document current effects and project future impacts as a basis for planning adaptive strategies.

Description: Brown planthopper (BPH), Nilaparvata lugens (Stal.) development studied at six constant temperatures, 19, 22, 25, 28, 31 and 33 ±1 °C on rice plants revealed that developmental period from egg hatching to adult longevity decreased from 46.8 to 18.4 days as temperature increased from 19 to 31 °C. Through regression of development rate on temperature, thermal constant of small nymph (1st-2nd instar), large nymph (3rd–5th instar) and adult were determined to be 126.6, 140.8 and 161.3 degree days (DD), respectively with corresponding development threshold being 8.8, 9.5 and 9.6 °C. A thermal constant-based mechanistic-hemimetabolous-population model was adapted for BPH and linked with InfoCrop, a crop simulation model to simulate climate change impact on both the pest population and crop-pest interactions. The model was validated with field data at New Delhi and Aduthurai (Tamil Nadu, India), ( R 2  = 0.96, RMSE = 1.87 %). Climate-change-impact assessment through coupled BPH-InfoCrop model, in the light of the projected climate-change scenario for Indian subcontinent, showed a decline of 3.5 and 9.3–14 % in the BPH population by 2020 and 2050, respectively, during the rainy season at New Delhi, while the pest population exhibited only a small decline of 2.1–3.5 % during the winter at Aduthurai by 2050. BPH population decline is attributed to reduction in fecundity and survival by simulation model, which otherwise was not possible to account for with an empirical model. Concomitant to its population decline, BPH-induced yield loss also indicated a declining trend with temperature rise. However, the study considered the effect of only CO 2 and temperature rise on the BPH population and crop yield, and not that of probable changes in feeding rate and adaptive capacity of the pest.

Description: Energy efficiency is one of the main options for mitigating climate change. An accurate representation of various mechanisms of energy efficiency is vital for the assessment of its realistic potential. Results of a questionnaire show that the EMF27 models collectively represent known channels of energy efficiency reasonably well, addressing issues of energy efficiency barriers and rebound effects. The majority of models, including general equilibrium models, have an explicit end-use representation for the transportation sector. All participating partial equilibrium models have some capability of reflecting the actual market behavior of consumers and firms. The EMF27 results show that energy intensity declines faster under climate policy than under a baseline scenario. With a climate policy roughly consistent with a global warming of two degrees, the median annual improvement rate of energy intensity for 2010–2030 reaches 2.3 % per year [with a full model range of 1.3–2.9 %/yr], much faster than the historical rate of 1.3 % per year. The improvement rate increases further if technology is constrained. The results suggest that the target of the United Nations’ “Sustainable Energy for All” initiative is consistent with the 2-degree climate change target, as long as there are no technology constraints. The rate of energy intensity decline varies significantly across models, with larger variations at the regional and sectoral levels. Decomposition of the transportation sector down to a service level for a subset of models reveals that to achieve energy efficiency, a general equilibrium model tends to reduce service demands while partial equilibrium models favor technical substitution.

Description: This paper provides an overview of climate change impacts on tribal water resources and the subsequent cascading effects on the livelihoods and cultures of American Indians and Alaska Natives living on tribal lands in the U.S. A hazards and vulnerability framework for understanding these impacts is first presented followed by context on the framework components, including climate, hydrologic, and ecosystem changes (i.e. hazards) and tribe-specific vulnerability factors (socioeconomic, political, infrastructural, environmental, spiritual and cultural), which when combined with hazards lead to impacts. Next regional summaries of impacts around the U.S. are discussed. Although each tribal community experiences unique sets of impacts because of their individual history, culture, and geographic setting, many of the observed impacts are common among different groups and can be categorized as impacts on—1) water supply and management (including water sources and infrastructure), 2) aquatic species important for culture and subsistence, 3) ranching and agriculture particularly from climate extremes (e.g., droughts, floods), 4) tribal sovereignty and rights associated with water resources, fishing, hunting, and gathering, and 5) soil quality (e.g., from coastal and riverine erosion prompting tribal relocation or from drought-related land degradation). The paper finishes by highlighting potentially relevant research questions based on the five impact categories.

Description: The scientific community is now developing a new set of scenarios, referred to as Shared Socio-economic Pathways (SSPs) that will be contrasted along two axes: challenges to mitigation, and challenges to adaptation. This paper proposes a methodology to develop SSPs with a “backwards” approach based on (i) an a priori identification of potential drivers of mitigation and adaptation challenges; (ii) a modelling exercise to transform these drivers into a large set of scenarios; (iii) an a posteriori selection of a few SSPs among these scenarios using statistical cluster-finding algorithms. This backwards approach could help inform the development of SSPs to ensure the storylines focus on the driving forces most relevant to distinguishing between the SSPs. In this illustrative analysis, we find that energy sobriety, equity and convergence prove most important towards explaining future difference in challenges to adaptation and mitigation. The results also demonstrate the difficulty in finding explanatory drivers for a middle scenario (SSP2). We argue that methodologies such as that used here are useful for broad questions such as the definition of SSPs, and could also be applied to any specific decisions faced by decision-makers in the field of climate change.

Description: Background and aims The effect of forest cover distribution and plant litter input on soil organic carbon were analyzed to better understand the dynamics of carbon cycling across ecosystems on the “Natural Oriented Reserve Bosco delle Pianelle”. Fluorescence spectroscopy represents a very useful tool to characterize soil organic matter properties, since it allows to directly monitor the molecular status of a fluorophore depending on its chemical environment, as well as on its structure, substituents of the aromatic moieties, and molecular weight. Here, fluorescence analysis was performed on humic acids isolated from four litters (HALs) and their underlying soils (HAs) at three depths. Methods All samples were collected from a protected forest area, Southern Italy, under different plant covering: Quercus ilex L. (Q), mixed Carpinus betulus L. and Carpinus orientalis Mill. (CC), Pinus halepensis L. (P), and mixed Quercus trojana Webb. and Quercus ilex L. (QQ). Results Data obtained showed a fast decomposition process for P and QQ litters, with HAs in the underlying soils characterized by the presence of simple, highly fluorescent structural components also in the deepest layers. On the contrary, a slow decomposition process was observed for Q and CC litters, whose underlying soil HAs were characterized by an increasing aromatic polycondensation and humification degree from the surface to the deepest layers, as supported by low values of fluorescence intensity and high wavelength maxima. Conclusions Results obtained indicate that P and QQ species promote C accumulation and stock in the underlying soils, thanks to a greater decomposition of their litter, and fluorescence spectroscopy is a very simple and suitable method to evaluate the influence of three species distribution on soil organic carbon pools.

Description: This study developed an approach to assess the vulnerability to climate change and variability using various group multi-criteria decision-making (MCDM) methods and identified the sources of uncertainty in assessments. MCDM methods include the weighted sum method, one of the most common MCDM methods, the technique for order preference by similarity to ideal solution (TOPSIS), fuzzy-based TOPSIS, TOPSIS in a group-decision environment, and TOPSIS combined with the voting methods (Borda count and Copeland’s methods). The approach was applied to a water-resource system in South Korea, and the assessment was performed at the province level by categorizing water resources into water supply and conservation, flood control and water-quality sectors according to their management objectives. Key indicators for each category were profiled with the Delphi surveys, a series of questionnaires interspersed with controlled opinion feedback. The sectoral vulnerability scores were further aggregated into one composite score for water-resource vulnerability. Rankings among different MCDM methods varied in different degrees, but noticeable differences in the rankings from the fuzzy- and non-fuzzy-based methods suggested that the uncertainty with crisp data, rather widely used, should be acknowledged in vulnerability assessment. Also rankings from the voting-based methods did not differ much from those from non-voting-based (i.e., average-based) methods. Vulnerability rankings varied significantly among the different sectors of the water-resource systems, highlighting the need to assess the vulnerability of water-resource systems according to objectives, even though one composite index is often used for simplicity.

Description: Dramatic climatic change in the Arctic elevates the importance of determining the risk of exposure for people living in vulnerable areas and developing effective adaptation programs. Climate change assessment reports are valuable, and often definitive, sources of information for decision makers when constructing adaptation plans, yet the scope of these reports is too coarse to identify site-specific exposure to the impacts of climate change and adaptation needs. Subsistence hunters and gatherers in the Arctic are valuable knowledge holders of climate-related change in their area. Incorporating both their traditional ecological knowledge and information found in climate science assessment reports can offer adaption planners a deeper understanding of exposure to climate change and local adaptation needs. In this study, we compare information found in assessment reports of climate change in the Arctic with what we have learned from the Alaskans Sharing Indigenous Knowledge project from 2009 to 2012, a research project documenting traditional ecological knowledge in two Native villages in Alaska, Savoonga and Shaktoolik. Content analysis of the interviews with hunters and gatherers reveal the site-specific impacts of climate change affecting these two villages. We find that their traditional ecological knowledge is complimentary and largely corroborates the climate science found in assessment reports. Traditional ecological knowledge, however, is more current to the social and local conditions of the villages, and presents a more unified social and biophysical portrayal of the impacts of climate change. If taken together, these two forms of knowledge can focus adaptation planning on the pertinent needs of the communities in question.

Description: We present projections of winter storm-induced insured losses in the German residential building sector for the 21st century. With this aim, two structurally most independent downscaling methods and one hybrid downscaling method are applied to a 3-member ensemble of ECHAM5/MPI-OM1 A1B scenario simulations. One method uses dynamical downscaling of intense winter storm events in the global model, and a transfer function to relate regional wind speeds to losses. The second method is based on a reshuffling of present day weather situations and sequences taking into account the change of their frequencies according to the linear temperature trends of the global runs. The third method uses statistical-dynamical downscaling, considering frequency changes of the occurrence of storm-prone weather patterns, and translation into loss by using empirical statistical distributions. The A1B scenario ensemble was downscaled by all three methods until 2070, and by the (statistical-) dynamical methods until 2100. Furthermore, all methods assume a constant statistical relationship between meteorology and insured losses and no developments other than climate change, such as in constructions or claims management. The study utilizes data provided by the German Insurance Association encompassing 24 years and with district-scale resolution. Compared to 1971–2000, the downscaling methods indicate an increase of 10-year return values (i.e. loss ratios per return period) of 6–35 % for 2011–2040, of 20–30 % for 2041–2070, and of 40–55 % for 2071–2100, respectively. Convolving various sources of uncertainty in one confidence statement (data-, loss model-, storm realization-, and Pareto fit-uncertainty), the return-level confidence interval for a return period of 15 years expands by more than a factor of two. Finally, we suggest how practitioners can deal with alternative scenarios or possible natural excursions of observed losses.

Description: Liquid fuels will remain valued energy carriers well into any upcoming period when CO 2 reductions are sought. Biofuels are the presumed replacement for the petroleum-based transportation fuels that dominate liquid fuel use. Lifecycle analysis embeds a closed-loop model of biofuel-related carbon flows, making net CO 2 uptake an assumption to be refuted. However, evaluating net CO 2 uptake through dynamic industrial and agriforestry supply chains at real-world commercial scales is extremely difficult. All such estimates carry a great deal of doubt and cannot be verified empirically. A different perspective follows by anchoring analysis in the certainty that end-use CO 2 emissions from biofuels are essentially the same as those of the petroleum fuels they replace. A first-order model of the globally coupled bio- and fossil-fuel system reveals conditions for biofuel use to provide an atmospheric benefit. No benefit occurs in the energy sectors where biofuels are used, but rather must be found elsewhere in locations of carbon absorption or retention. The implication is that climate mitigation efforts should focus on such locations and include any mechanisms through which net uptake (an enhanced sink or verifiable offset) can be achieved by biological, chemical, geological or other means. Although biofuels can play a mitigation role when certain conditions are met, deemphasizing biofuel production in favor of terrestrial carbon management may offer more immediate and effective ways to counterbalance the CO 2 emitted when using carbon-based liquid fuels of any origin. Climate policies for transportation fuels should be reconsidered accordingly.

Description: ENSO teleconnections imply anomalous weather conditions, causing yield shortages, price fluctuations, and civil unrest. We estimate ENSO’s effect on U.S. county-level corn yield distributions and find that temperature and precipitation alone are not sufficient to summarize the effect of global climate on agriculture. We find that acreage-weighted aggregate impacts mask considerable spatial heterogeneity at the county-level for the mean, variance, and downside risk of corn yields. Impacts for mean yields range from − 24 to 33 % for El Niño and − 25 to 36 % for La Niña, with the geographical center of losses shifting from the Eastern to Western corn belt. ENSO’s effect on the variance of crop yields is highly localized and is not representative of a variance-preserving shift. We also find that downside risk impacts are large and spatially correlated across counties.

Description: It is generally agreed that the risk of catastrophic climate change can only be reduced if agents cooperate to reduce greenhouse gas emissions over the course of the 21st Century. Previous economic experiments have suggested that sufficient cooperation can often be achieved providing individuals are adequately and convincingly informed of the consequences of their actions and the stakes involved. However, this previous work, has not allowed for the fact that in the real world agents vary in both: (1) their resources to mitigate climate change, and (2) the consequences that they face from climate change. We develop and expand the protocol of previous economic experiments to investigate the introduction of such combined asymmetries. We find that when inequality in resources is combined with a greater relative risk for poorer members, cooperation collapses, with tragic consequences. This is because the rich invest proportionally less into preventing climate change when they are less at risk. We also find, through the use of a post-game questionnaire, that those individuals who were more skeptical about climate change in the real world cooperated less in our games. Insofar as such experiments can be trusted as a guide to either people’s everyday behaviour or the interactions of nation states, these results suggest that voluntary cooperation to avoid climate catastrophe in the real world is likely to be hard to achieve.

Description: There is growing concern that the higher temperatures expected with climate change will exacerbate drought extent, duration and severity by enhancing evaporative demand. Temperature-based estimates of potential evapotranspiration (PET) are popular for many eminently practical reasons and have served well in many research and management settings. However, a number of recent publications have questioned whether it is appropriate to use temperature-based PET estimates for long-term evaporative demand and drought projections, demonstrating that PET does not always track temperature. Where precipitation changes are modest, methodologically driven differences in the magnitude or direction of PET trends could lead to contrasting drought projections. Here I calculate PET by three methods (Hamon, Priestley-Taylor and Penman) and evaluate whether different techniques introduce disparities in the sign of PET change, the degree of model agreement, or the magnitude of those changes. Changes in temperature-based Hamon PET were more significantly and consistently positive than trends in PET estimated by other methods, and where methods agreed that summer PET would increase, trends in temperature-based PET were often larger in magnitude. The discrepancies in PET trends appear to derive from regional changes in incoming shortwave radiation, wind speed and humidity -- phenomena simpler equations cannot capture. Because multiple variables can influence trends in PET, it may be more justifiable to use data-intensive methods, where the source(s) of uncertainty can be identified, rather than using simpler methods that could mask important trends.

Description: Cities are increasingly aware of the need to mitigate greenhouse gas emissions and adapt to changes in weather patterns leading to the production of urban climate change plans. The few existing systematic studies of these plans have focused on either adaptation or mitigation issues, and are typically based on surveys completed by city officials rather than analysis of documented evidence. To gain insight into the status of adaptation and mitigation action across the UK, climate change documents from 30 urban areas (representing ~28 % of the UK’s population) were analysed. An Urban Climate Change Preparedness Score, which could be applied to other urban areas outside the UK, has been devised for comparative analysis. This analysis characterizes progress against (i) Assessment, (ii) Planning, (iii) Action, and (iv) Monitoring, for both adaptation and mitigation. The Preparedness Score allows a quantitative comparison of climate change strategies across the urban areas analysed. This methodology can be transferred to other countries and makes an international comparison of urban areas and their climate change adaptation and mitigation plans possible. We found that all areas acknowledge climate change being a threat and that adaptation and mitigation planning and action is required. However, two urban areas did not have official adaptation or mitigation plans. Typically, mitigation activities across all cities were more advanced than adaptation plans. Emissions reduction targets ranged from 10 %–80 % with differing baselines, timeframes and scopes, for defining and meeting these targets. Similar variability was observed across adaptation plans. Several reasons for these differences are considered, but particularly notable is that a combination of incentives and regulation seem to stimulate more comprehensive strategies and action in many urban areas.

Description: Aims The objective of our study was to confirm if hydraulic lift (HL) promotes nutrient uptake in field-grown plants in the same way as demonstrated previously in pot-grown plants. Methods We conducted a field experiment in an agroforestry system, over an entire growing season that included a dry period and a wet period. We used a shallow-root crop plant, mung bean ( Vigna radiata L.), intercropped with walnut ( Juglans regia L.) and jujube ( Zizyphus jujube Mill.), as an indicator for the presence of HL and its effects on nutrient uptake. To monitor HL, we artificially applied deuterium isotope to the deep roots of trees. Results We demonstrated the presence of a natural nitrogen, phosphorus, and potassium gradient along the soil depth, and the occurrence of HL, evidenced by deuterium signature in the shallow soil layers and V. radiata stem, only during the dry season. J. regia and Z. jujube both had deep root systems, but the former species exhibited stronger HL to the shallow soil than the latter. Meanwhile, the upper soil layers of J. regia had significantly higher moisture content, and the intercropped V. radiata had higher nutrient content. Conclusion HL can facilitate water uptake by V. radiata from the upper soil layers in the field condition during the dry season, which relates to nutrient acquisition by the crop.

Description: In this paper, we assessed the technological feasibility and economic viability of the mid-term (until 2050) GHG emission reduction target required for stabilization of radiative forcing at 2.6 W/m2. Given the apparent uncertainty surrounding the future deployment of nuclear and CCS technologies, we intensively investigated emission reduction scenarios without nuclear and CCS. The analysis using AIM/Enduse[Global] shows the emission reduction target is technologically feasible, but the cost for achieving the target becomes very high if nuclear and CCS options are limited. The main reason for the cost rise is that additional investment for expensive technologies is required in order to compensate for emission increases in the steel, cement and power generation sectors in the absence of CCS. On the other hand, if material efficiency improvement measures, such as material substitution, efficient use of materials and recycling, are taken, the cost of achieving the emission reduction target is significantly reduced. The result indicates the potentially important role of material efficiency improvement in curbing the cost of significant GHG emission reductions without depending on nuclear and CCS.

Description: The RoSE (Roadmaps to Sustainable Energy Futures) project provides a coordinated, model-based analysis to manage the transition from carbon intensive to low carbon economies using several global integrated assessment models to explore different GHG stabilization scenarios. China TIMES provides a detailed description of the Chinese energy system that can be used to check the realism of transition scenarios for China against global models. A reference scenario with China’s target of lowering its carbon intensity by 40–45 % by 2020 compared to the 2005 level is considered, and 12 carbon constraint scenarios with different levels of carbon intensity reduction beyond 2020 are simulated by China TIMES. The results of carbon emissions pathways and energy system transitions in different scenarios are analyzed. The results from China TIMES are compared to those for both the reference and carbon policy scenarios (550 ppm CO2eq and 450 ppm CO2eq stabilization targets) for four global models, GCAM, IPAC, REMIND, and WITCH. The differences in decarbonizaton pathways across models are mainly attributed to different model structures and modeling approaches, different reference scenario definitions, different policy targets, differences in model assumptions concerning technology availability and techno-economic characteristics of the technologies, and differences in the estimation of the energy demand response to climate policy. The path towards low carbon development for China includes challenges and opportunities. Substantial efforts may be required to transform the economic development mode, to speed up innovation, R&D, and deployment of advanced low carbon technologies, to strengthen institutions, to advocate low carbon lifestyles, and to enhance international cooperation.

Description: Aims and background Despite increasing knowledge of the role of allelochemicals in the productivity decline of replanted Chinese fir plantations, relatively little is known about the levels and sources of allelochemicals in relation to autoinhibition. Methods Allelopathic potential of litter, root exudates, and soils in successive rotations of Chinese fir plantations were detected. An allelochemical cyclic dipeptide (6-hydroxy-1,3-dimethyl-8-nonadecyl-[1,4]-diazocane-2,5-dione) from litter, root exudates, and soils in successive rotations was quantified. Results Extracts of leaf litter, fine root, and root exudates significantly inhibited the growth of Chinese fir germinants, and inhibition increased with successive rotations. Similar results were observed in the rhizosphere soil, basal soil, and bulk soil. The largest observed inhibition occurred in the rhizosphere soil. Furthermore, cyclic dipeptide was found in litter, root exudates, and soils, and the concentrations increased with successive rotations. The rhizosphere soil had the highest cyclic dipeptide level, followed by basal soil, while bulk soil contained the lowest concentration. There was a significant positive relationship between the inhibition of radicle growth of Chinese fir germinants and the concentration of cyclic dipeptide. Annual release of cyclic dipeptide through root exudation was 2.08–9.78 mol ha −1 annum, but the annual release of cyclic dipeptide through leaf litter decomposition was lowered to 0.32–1.41 mol ha −1 annum. Conclusions Cyclic dipeptide which caused autoinhibition of Chinese fir may be released into the soil through litter decomposition and root exudation. Root exudates provided more contributions to soil cyclic dipeptide levels than litter in Chinese fir plantations.

Description: Background and aims In the Central Negev hills (Israel) many ancient terraced wadis exist, which captured run-off and caused gradual soil aggradation, which enabled agricultural practices. In these terraces, dark colored soil horizons were observed, containing charcoal, as can be found in Terra Preta soils, suggesting higher fertility compared to natural soils. The aim of our investigation was to investigate these anthropogenic soils and to study the effects of charcoal and ash addition on soil properties and crop growth. Methods We investigated 12 soil profiles, focusing on possible differences between light and dark colored soil horizons. We also investigated the effects of amendment of charcoal and ash on the growth of wheat ( Triticum Aestivum L. ) in a 40-day pot experiment involving two water regimes. Results Results show that charcoal content in light and dark horizons were both low (〈0.2 %), but significantly lower bulk densities were found in dark colored horizons. In the crop experiment, charcoal addition resulted in decreased crop growth, while, in the water deficit regime, ash addition resulted in increased crop growth. Conclusions Considering the observed charcoal and the results from the crop experiment, we hypothesize that, in ancient run-off capturing agricultural systems, ash was purposefully added as fertilizer.

Description: This study investigates the use of bioenergy for achieving stringent climate stabilization targets and it analyzes the economic drivers behind the choice of bioenergy technologies. We apply the integrated assessment framework REMIND-MAgPIE to show that bioenergy, particularly if combined with carbon capture and storage (CCS) is a crucial mitigation option with high deployment levels and high technology value. If CCS is available, bioenergy is exclusively used with CCS. We find that the ability of bioenergy to provide negative emissions gives rise to a strong nexus between biomass prices and carbon prices. Ambitious climate policy could result in bioenergy prices of 70 $/GJ (or even 430 $/GJ if bioenergy potential is limited to 100 EJ/year), which indicates a strong demand for bioenergy. For low stabilization scenarios with BECCS availability, we find that the carbon value of biomass tends to exceed its pure energy value. Therefore, the driving factor behind investments into bioenergy conversion capacities for electricity and hydrogen production are the revenues generated from negative emissions, rather than from energy production. However, in REMIND modern bioenergy is predominantly used to produce low-carbon fuels, since the transport sector has significantly fewer low-carbon alternatives to biofuels than the power sector. Since negative emissions increase the amount of permissible emissions from fossil fuels, given a climate target, bioenergy acts as a complement to fossils rather than a substitute. This makes the short-term and long-term deployment of fossil fuels dependent on the long-term availability of BECCS.

Description: Introduction In a recent paper, Warren et al. ( 2013 ) illustrated the potential of neutron radiography to visualize water dynamics in soil and plants. Methods After injection of deuterated water (D 2 O) in soil, the authors could monitor the changes of D 2 O concentration in roots. Results Based on the radiographs, the authors concluded that D 2 O was transported from roots growing in a wet soil region to roots in a dry region, proving hydraulic redistribution between roots. However, this interpretation depends on the correct estimation of D 2 O concentration in soil. Conclusions The experiments of Warren et al. ( 2013 ) could also be explained by diffusion of D 2 O from soil to roots, without hydraulic redistribution within the root system.

Description: Aims The mechanisms of belowground competition are not well understood. Addressing literature reports on competition-induced changes in tree fine root morphology, we conducted a growth experiment with tree saplings to investigate competition effects on important root morphological and functional traits in a root order-focused analysis. Methods European beech and European ash saplings were grown for 34 months in containers under greenhouse conditions in monoculture (2 conspecific plants), in mixture (1 beech and 1 ash) or as single plants. The root system was fractionated according to root orders and eight morphological and functional properties were determined. Results Root order was the most influential factor affecting the fine root traits (except for root diameter and δ 13 C); a significant species identity effect was found for root diameter, tissue density, N concentration and δ 13 C. Ash fine roots were thicker, but had lower tissue densities, contained more N and had systematically higher δ 13 C values than beech roots. The competition treatments had no significant effect on morphological root traits but altered δ 13 C in the 2nd root order. Conclusion Neither intra- nor interspecific root competition affected fine root morphology significantly suggesting that competition-induced root modification may not be a universal phenomenon in temperate trees.

Description: The sustainability of social-ecological systems depends on river flows being maintained within a range to which those systems are adapted. In order to determine the extent of this natural range of variation, we assess ecological flow thresholds and the occurrence of potentially damaging flood events to society in the context of the Lower Brahmaputra river basin. The ecological flow threshold was calculated using twenty-two ‘Range of Variability (RVA)’ parameters, considering the range between ± 1 standard deviation from the mean of the natural flow. Damaging flood events were calculated using flood frequency analysis of Annual Maxima series and using the flood classification of Bangladesh. The climate change impacts on future river flow were calculated by using a weighted ensemble analysis of twelve global circulation models (GCMs) outputs driving a large-scale hydrologic model. The simulated climate change induced altered flow regime of the Lower Brahmaputra River Basin was then investigated and compared with the calculated threshold flows. The results demonstrate that various parameters including the monthly mean of low flow (January, February and March) and high flow (June, July and August) periods, the 7-day average minimum flow, and the yearly maximum flow will exceed the threshold conditions by 1956–1995 under the business-as-usual A1B and A2 future scenarios. The results have a number of policy level implications for government agencies of the Lower Brahmaputra River Basin, specifically for Bangladesh. The calculated thresholds may be used as a good basis for negotiations with other riparian countries of the basin. The methodological approach presented in this study can be applied to other river basins and provide a useful basis for transboundary water resources management.

Description: Background and aims Distinct metal distribution patterns within leaves of metal hyperaccumulating plants are repeatedly observed however, the presumable role of key structural biochemical molecules in determining and regulating their allocation remains largely unknown. We aimed to characterise in a spatially resolved manner the distribution of the main biochemical components in leaves of field-collected Cd/Zn-hyperaccumulating Noccaea praecox in order to relate them to metal distribution patterns at tissue level. Methods The biomolecular composition of the leaves was spatially analysed using synchrotron radiation Fourier Transform Infrared (FTIR) and the distribution of Zn with synchrotron radiation Low-Energy X-Ray Fluorescence (LEXRF) microspectroscopy was determined on the same tissues of interest (epidermis, sub-epidermis, mesophyll). Results In epidermal cells high proportion of free-carboxyl, nitro and phosphate groups standing for pectin, nitroaromatics, phytic and other organic acids were found. Adjacent mesophyll cells had higher proportions of proteins, carbohydrates and cellulosic compounds. Conclusions Pectin compounds were indicated as important components of Zn enriched epidermal cell walls. In addition, intense lignification of epidermal cell walls might limit leakage of the trapped metals back to the metabolically active and thus more sensitive mesophyll. Distribution of metal-binding compounds in particular cell types/tissues may therefore predispose metal distribution patterns and tolerance in leaves.

Description: Aims Tree species affect herb layer species through their effects on soil quality and light regime but their relative importance and interactions are insufficiently known. Methods Pot experiment with soil taken from stands planted with tree species with contrasting effects on soil acidification, two light regimes and six forest perennials. Results The survival or growth of Mercurialis perennis, Lamium galeobdolon , Anemone nemorosa and Primula elatior was lower in the acid Alnus soils than in the less acid Fraxinus soils. By contrast, the acid tolerant Convallaria majalis and Dryopteris dilatata were barely affected by tree species. Light conditions had less impact than soil chemistry and did not compensate for unfavourable soil conditions. Ca and P concentrations increased in plants grown in Fraxinus soils. The Mg and Al shoot/root ratios of respectively one and two of the acid tolerant species was elevated in the most acid soil. Conclusions Tree species effects on forest perennials are mainly explained by increased Al concentrations under acidifying species. Changed plant concentrations and allocation are likely associated to Al antagonism. We found no light compensation for the soil effect on the studied species. However, light alters the plant nutrient concentrations and allocation which may suggest an indirect effect.

Description: Aims The aim of this study was to determine whether goat grazing in the understory of a pine forest at Doñana Natural Park could accelerate the decomposition of the pine needles accumulated on the soil surface and, if so, through which mechanisms. Specifically, the roles of trampling (mechanical fragmentation) and nutrient enrichment through defecation (fertilization) were evaluated in terms of their effect on pine needle decomposition rates. Methods An experiment was conducted featuring the following 4 treatments: 1) intact needles (control), 2) trampled needles, 3) intact needles fertilized with liquid manure, and 4) trampled needles fertilized with liquid manure. Litter decomposition was determined as a function of mass loss over time, using the litter-bag method. Bags were recovered 4, 8, 16, 24 and 36 months after burial in soil, dried and weighed. Needle length, leaf mass per area and C and N concentration were also measured in the buried litter-bags. Results Four months after burial, mass loss was greater in the trampled (23–27 %) than non-trampled (14–16 %) treatments. However, from 8 months onwards, decomposition rates in the fertilized treatments were significantly higher than those in the non-fertilized treatments (between 5 % and 15 % less mass loss). Meanwhile, fertilized treatments presented higher N content (2.1 %) than the non-fertilized ones (1.2 %), with a significantly lower C:N ratio also found in the in the fertilized treatment. Conclusions Trampling and fertilization during grazing accelerates litter decomposition and thus promotes the incorporation of N into the system. Acceleration of decomposition reduces the accumulation of pine needles on the soil surface, reducing the risk of fire.

Description: We present new tree-ring width, δ 13 C, and δ 18 O chronologies from the Koksu site (49°N, 86° E, 2,200 m asl), situated in the Russian Altai. A strong temperature signal is recorded in the tree-ring width (June-July) and stable isotope (July-August) chronologies, a July precipitation signal captured by the stable isotope data. To investigate the nature of common climatic patterns, our new chronologies are compared with previously published tree-ring and stable isotope data from other sites in the Altai region. The temperature signal preserved in the conifer trees is strongly expressed at local and regional scales for all studied sites, resulting in even stronger temperature and precipitation signals in combined average chronologies compared to separate chronologies. This enables the reconstruction of June-July and July-August temperatures for the last 200 years using tree-ring and stable carbon isotopes. A July precipitation reconstruction based on oxygen isotopic variability recorded in tree-rings can potentially improve the understanding of hydrological changes and the occurrence of extreme events in the Russian Altai.

Description: The US climate movement has failed to create the political support needed to pass significant climate policy. It is time to reassess climate advocacy. To develop a strategy for philanthropy to strengthen climate engagement, I interviewed over 40 climate advocates,more than a dozen representatives from the foundation community, and a dozen academics. My assessment led me to conclude that climate advocates have focused too narrowly on specific policy goals and insufficiently on influencing the larger political landscape. I suggest four ways to improve climate advocacy: 1) Increase focus on medium and longer-term goals; 2) Start with people and not carbon; 3) Focus more on values and less on science; and 4) Evaluate what works and share what we learn. To accomplish these strategies, social scientists and advocates must work together to build a culture of learning. Meanwhile, philanthropy must empower experimentation and incentivize knowledge sharing.

Description: We study the possible effects of urbanization on the rise of air temperature in Saudi Arabia for the period 1981–2010. The effects of variations in elevation and marine temperature on the air temperature trend are also investigated. Surface air temperature data are analyzed for 24 sites which are mostly located at the airports across the country. The population data for the current (2010) and earlier (2004 and 1992) censuses are used for the nearest cities where the observation sites are located. A national average is calculated using two different approaches (simple averaging and weighted according to area for 1985–2010 when all stations are available) which gives trends of 0.60 and 0.51 °C/decade respectively, both significant at the 99 % level. We find no link between the temperature increase and population increase nor with elevation at the 24 sites which are mostly located in the urban effected area but not at the city centers. This suggests that the rise in air temperature is not likely due to urbanization changes resulting from the population increases.

Description: Background and aims Cadmium (Cd) could activate activity of mitogen-activated protein kinase MPK6 in plants. In this study, we investigated the role of MPK6 in mediating Cd toxicity in plants. Methods The wild type Arabidopsis plants (WT) and the mpk6 - 2 mutants were subjected either 0 (Control) or 10 μM Cd treatment. Kinase activity of MPK6, nitric oxide (NO) level, Cd concentration, and oxidative stress were measured. Results In WT plants, Cd exposure rapidly stimulated kinase activity of MPK6. However, upon Cd exposure, mpk6 - 2 showed better growth than the WT. Although Cd-induced production of NO in roots was greater in WT than in mpk6 - 2 , there was no difference in Cd concentration between the two plants. Nevertheless, the Cd-induced hydroperoxide burst, lipid peroxidation and loss of membrane integrity, were all more severe in the WT than in mpk6 - 2 . Foliar applications of antioxidant ascorbic acid, vigorously improved the growth of both the WT and mpk6 - 2 under Cd exposure. Thereby the growth difference between these two plants was minimized. Conclusions Mutation of mpk6 enhances Cd tolerance in plants by alleviating oxidative stress, but did not affect cadmium accumulation in plants.

Description: Background and Aims The role and linkage of endophytic bacteria to resistance of peanut seeds to biotic stress is poorly understood. The aims of the present study were to survey the experimental (axenic) and control (conventional) peanut plants for the predominant endophytic bacteria, and to characterize isolates with activity against selected A. flavus strains. Methods Young axenic plants were grown from presumably bacteria-free embryos in the lab, and then they were grown in a field. Endophytic bacterial species were identified by the analysis of DNA sequences of their 16S-ribosomal RNA gene. DNA extracted from soil was also analyzed for predominant bacteria. Results Mature seeds from the experimental and control plants contained several species of nonpathogenic endophytic bacteria. Among the eight bacterial species isolated from seeds, and DNA sequences detected in soil, Bacillus thuringiensis was dominant. All B. amyloliquefaciens isolates, the second abundant species in seeds demonstrated activity against A. flavus . This effect was not observed with any other bacterial isolates. There was no significant difference in number and relative occurrence of the two major bacterial species between the experimental and conventionally grown control seeds. Conclusion Endophytic bacterial colonization derives from local soil and not from the seed source, and the peanut plant accommodates only selected species of bacteria from diverse soil populations. Some bacterial isolates showed antibiosis against A. flavus.

Description: Background and Aims Climate warming and increased atmospheric nitrogen (N) deposition both have the potential to increase plant productivity over the next century, yet they can also increase decomposition and respiration. Our aim was to examine the extent to which warming and N addition can, on balance, alter net ecosystem CO 2 exchange (NEE) in a grass-dominated system. Methods We measured NEE responses to warming and N addition over two growing seasons in a temperate old field using steady-state flow-through chambers, which allowed for the integrated measurement of respiration and photoassimilation effects on net CO 2 flux over diel periods. We also assessed the relationship between NEE and plant biomass responses to the warming and N treatments. Results In both years, our study system was a net source of carbon (C) during the snow-free season. N addition did not significantly affect diel NEE or dark respiration in either year, despite a doubling in aboveground plant biomass in response to N addition in the second year, and a corresponding increase in peak daily net CO 2 photoassimilation in N addition plots. The warming treatment also had no significant effect on NEE, although the flow-through chambers required warming to be temporarily halted during NEE measurements. Conclusions Overall, our results both highlight the potential divergence of plant and soil responses to N addition and demonstrate the capacity for a grass-dominated system to function as a net source of C in consecutive years.

Description: Background and aim Intuitively, access to water from the soil at key phenological stages is important for adaptation to drought. This study aimed to assess the temporal pattern of water extraction under terminal drought stress. Methods Pearl millet genotypes with varying levels of terminal drought tolerance were grown in a lysimetric system with a soil volume and plant spacing similar to field conditions. Water extraction was monitored until maturity under differing water regimes. Results The yield did not differ among genotypes under well-watered (WW) conditions, and the water extraction profile of WW plants was similar across all genotypes. In contrast, the yield of sensitive genotypes was 30–100 % lower than that of tolerant lines under water stress (WS). The total volumes of water extracted by tolerant and sensitive genotypes were similar under WS; however, tolerant genotypes extracted less water prior to anthesis, and more water after anthesis. Grain yield was positively related to the amount of water extracted during week three after panicle emergence. Increased water extraction after anthesis benefitted the tillers more than the main culm and was correlated with higher staygreen scores. Conclusion Increased water uptake after anthesis, which results from earlier water conservation during pre-anthesis, increases yield under terminal drought in pearl millet.

Description: Background and aims Efficient accumulation of arsenic (As) in rice ( Oryza sativa L.) poses a potential health risk to rice consumers. The aim of this study was to investigate the mechanisms of uptake, transport and distribution of inorganic arsenic (As i ) and dimethylarsinic acid (DMA) in rice plants. Methods Rice was exposed to As i (As(V)) and DMA in hydroponics. High-performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and synchrotron X-ray fluorescence (SXRF) microprobe were used to determine As concentration and the in situ As distribution. Results DMA induced abnormal florets before flowering and caused a sharp decline in the seed setting rate after flowering compared to As i . Rice grains accumulated 2-fold higher DMA than As i . The distribution of As i concentration (root 〉 leaf 〉 husk 〉 caryopsis) in As(V) treatments was different from that of the DMA concentration (caryopsis 〉 husk 〉 root ≥ leaf) in DMA treatments. SXRF showed that As i mainly accumulated in the vascular trace of caryopsis with limited distribution to the endosperm, whereas DMA was observed in both tissues. Conclusions DMA tended to accumulate in caryopsis and induced higher toxicity to the reproductive tissues resulting in markedly reduced grain yield, whereas As i mainly remained in the vegetative tissues and had no significant effect on yield. DMA is more toxic than As i to the reproductive tissues when both of them are at similar concentrations in nutrient solution.

Description: Background and aims Variations in responses to soil N between a non-N-fixing shrub, Baccharis halimifolia L., and a N-fixing shrub, Morella cerifera (L.) Small, were tested over 12 weeks to determine whether N availability is the sole cause of persistent dominance of M. cerifera on barrier islands. Methods Plants were supplied increasing levels of soil N up to 200 mg kg −1 . Measurements included gas exchange and chlorophyll fluorescence parameters across treatments, species, and time. Tissues were analyzed for differences in biomass and nutrients. Results Baccharis halimifolia had reduced physiological responses across all treatment levels, but M. cerifera had comparatively few variations. Across all treatments B. halimifolia photosynthesis and stomatal conductance were reduced by 62 and 76 %, respectively,by week 12. Increasing foliar δ 15 N values across treatments for M. cerifera indicated a shift from utilizing fixed N to available soil N. Biomass was highest at 200 mg kg −1  N for both species. Baccharis halimifolia showed indications of stress response and resource limitation based on physiological responses, nutrient contents, and isotope effects. Conclusions Baccharis halimifolia showed signs of co-limitation of both N and P whereas M. cerifera was limited by neither, suggesting that dominance of M. cerifera is only partially explained by actinorhizal symbiosis and N availability.

Description: Background and Aims Soil mineralization, nitrification, and dynamic changes in abundance of ammonia-oxidizing bacteria (AOB) and archaea (AOA) were studied to validate our hypothesis that soil mineralization and nitrification decreased along the chronosequence of rice cultivation. Methods Paddy soils with a 300, 700 and 2000-year cultivation history (P300, P700 and P2000) were selected to study net mineralization and nitrification processes. Dynamic abundance of AOB and AOA was estimated by quantifying their respective amoA gene copies. Results The net mineralization rate was higher for P300 than P700 and P2000. Potential nitrification ( N p ) and average nitrification rates ( V a ) were similar for P300 and P700 soils, but the simulated potential nitrification rate ( V p ) and nitrification rate (k 1 ) was 72 % and 88 % higher for P300 than P700, respectively. V a was about 70 % lower than for P2000 than P300 and P700. AOB amoA gene copies were higher for P300 than P700 and P2000, whereas AOA abundance did not show significant differences. AOB abundance showed a positive response to NH 4 supply but AOA did not. Conclusions Both N mineralization and nitrification were depressed with increased cultivation time. Archaea responded to mineralization positively rather than nitrification, which suggested that readily mineralized organic matter may play an important role in AOA.

Description: Aims The current study aimed to assess the potential of peanut ( Arachis hypogaea L.) for bioenergy production via phytoextraction in cadmium (Cd) -contaminated soils and screen appropriate cultivars for this approach. Methods A life-cycle pot experiment was conducted to determine the biomass, seed yield, oil content and Cd accumulation of seven peanut cultivars under Cd concentration gradients of 0, 2, and 4 mg kg −1 . Results Peanut exhibits genotypic variations in Cd tolerance, seed production, oil content, and Cd accumulation. Exposure of plants to 2 and 4 mg kg −1 Cd did not inhibit shoot biomass, seed yield, and oil content for most of the cultivars tested. There are large amounts of Cd accumulated in the shoots. Although the seed Cd concentration of peanut was relatively high, the Cd concentration in seed oils was very low (0.04-0.08 mg kg −1 ). Among the cultivars, Qishan 208 showed significant Cd tolerance, high shoot biomass, high pod and seed yield, high seed oil content, considerable shoot Cd concentration, and the largest translocation factor and total Cd in shoots. Conclusions The cultivation of peanut in Cd-contaminated farmland was confirmed to be feasible for bioenergy production via phytoextraction, and Qishan 208 is a good candidate for this approach.

Description: Background and aims Sufficient soil phosphorus (P) is important for achieving optimal crop production, but excessive soil P levels may create a risk of P losses and associated eutrophication of surface waters. The aim of this study was to determine critical soil P levels for achieving optimal crop yields and minimal P losses in common soil types and dominant cropping systems in China. Methods Four long-term experiment sites were selected in China. The critical level of soil Olsen-P for crop yield was determined using the linear-plateau model. The relationships between the soil total P, Olsen-P and CaCl 2 -P were evaluated using two-segment linear model to determine the soil P fertility rate and leaching change-point. Results The critical levels of soil Olsen-P for optimal crop yield ranged from 10.9 mg kg −1 to 21.4 mg kg −1 , above which crop yield response less to the increasing of soil Olsen-P. The P leaching change-points of Olsen-P ranged from 39.9 mg kg −1 to 90.2 mg kg −1 , above which soil CaCl 2 -P greatly increasing with increasing soil Olsen-P. Similar change-point was found between soil total P and Olsen-P. Overall, the change-point ranged from 4.6 mg kg −1 to 71.8 mg kg −1 among all the four sites. These change-points were highly affected by crop specie, soil type, pH and soil organic matter content. Conclusions The three response curves could be used to access the soil Olsen-P status for crop yield, soil P fertility rate and soil P leaching risk for a sustainable soil P management in field.

Description: Background and aims Gaseous losses of ammonia (NH 3 ) have been observed in citrus orchards when urea is surface-applied to the soils, and this loss might significantly limit the effectiveness of the nitrogen (N) fertilizer. However, a portion of the volatilized NH 3 might be absorbed by the plants through the leaves. To quantify the contribution of the leaf absorption of 15 NH 3 , a study with sweet oranges was conducted in two field areas where trees were grown at standard (480 trees ha −1 ) and high densities (617 trees ha −1 ). Methods Plastic trays were filled with soil, covered with mown grass to simulate field management conditions, fertilized with 15 N labeled urea (12 atom % excess) and placed under each of three trees in the orchards. This experimental procedure prevented the uptake of N from the labeled urea by the roots. Two weeks after 15 N fertilization, the trays were removed from the field, and the soil was homogenized and sampled for chemical analyses. The citrus trees under which the trays were placed were destructively harvested, and the total N concentrations and 15 N/ 14 N ratios were determined. Results After urea application, the NH 3 losses peaked within three days and subsequently decreased to negligible amounts after 10 days. The total NH 3 losses accounted for 55–82 % of the applied N. Although the NH 3 absorption by the citrus leaves was proportional to the tree density in the field, only 3–7 % of the 15 NH 3 volatilized from the soil was recovered by the citrus trees, and the NH 3 absorption was also influenced by the proximity of citrus trees to the site of urea application and the leaf areas of the trees. Conclusions The citrus trees can absorb the NH 3 volatilized from urea, even though, the amount recovered by the trees is small and does not represent a significant proportion of total gaseous N losses, what demonstrates the importance of enhanced N use efficiency practices in field to reduce losses of NH 3 when urea is applied to soil surfaces.

Description: Background Rice can accumulate arsenic (As) to relatively high concentrations due to the general flooding practices in rice cultivation, and organic matter in the soil strongly affected As bioavailability to rice plants. The influence of organic matter input on the As transformation in paddy soil and As uptake into rice plants is an area that is rarely investigated. Methods Biogas slurry (BGS), a commonly used organic fertilizer, was applied to an As contaminated paddy soil, in order to investigate the influence of organic matter on As transformation in the paddy soil and As accumulation in rice plants. Results Application of BGS significantly increased the As accumulation in rice plants, especially for methylated As species. Results showed that the concentrations of dissolved organic carbon (DOC) and dissolved Fe(II) in the soil solution were significantly increased by the BGS addition into the paddy soil, and were significantly correlated to the As concentration in the soil solution ( P  〈 0.01). The increase of soil pH and the decrease of the soil redox potential (Eh) were observed as well. These alteration of soil characteristics elevated the As release from soil particles to the soil solution under the addition of BGS. The increased concentrations of dimethylarsinic acid (DMAs(V)) and monomethylarsonic acid (MMAs(V)) in the soil solution, and the volatilized As of trimethylarsine (TMAs) from the paddy soil, suggested that As methylation and volatilization in the soil were also enhanced by BGS addition. The concentrations of methylated As species in rice husks and grains were increased by 105.8–105.9 % and 99.7–112.2 %, respectively. Conclusion These results suggested that the use of organic fertilizer, such as BGS in As-contaminated paddy soil, can significantly alter the behavior of As in soil-rice system and enhance As accumulation in rice plants and should therefore be avoided.

Description: Background & aims Plants may have dissimilar effects on ecosystem processes because they possess different attributes. Given increasing biodiversity losses, it is important to understand which plant traits are key drivers of ecosystem functions. To address this question, we studied the response of two ecosystem functions that remove nitrogen (N) from wetland soils, the accumulation of N in plant biomass and denitrification potential (DNP), to variation in plant trait composition. Methods Our experiment manipulated plant composition in a riparian wetland. We determined relative importance of plant traits and environmental variables as predictors of each ecosystem function. Results We demonstrate that Water Use Efficiency (WUE) had a strong negative effect on biomass N. Root porosity and belowground biomass were negatively correlated with DNP. Trait ordination indicated that WUE was largely orthogonal to traits that maximized DNP. Conclusions These results indicate that plant species with different trait values are required to maintain multiple ecosystem functions, and provide a more mechanistic, trait-based link between the recent findings that higher biodiversity is necessary for multi-functionality. While we selected plant traits based on ecological theory, several of the plant traits were not good predictors of each ecosystem function suggesting the ecological theory linking traits to function is incomplete and requires strengthening.

Description: The case of the Pyramid Lake Paiute Tribe exemplifies tribal vulnerabilities as a result of climate change. Preliminary socio-economic data and analysis reveal that the tribe’s vulnerability to climate change is related to cultural and economic dependence on Pyramid Lake, while external socio-economic vulnerability factors influence adaptive capacity and amplify potential impacts. Reduced water supplies as a consequence of climate change would result in a compounded reduction of inflows to Pyramid Lake, thus potentially impacting the spawning and sustenance of a cultural livelihood, the endangered cui-ui fish ( Chasmistes cujus ). Meanwhile, limited economic opportunities and dwindling federal support constrain tribal adaptive capacity. Factors that contribute to tribal adaptive capacity include: sustainability-based values, technical capacity for natural resource management, proactive initiatives for the control of invasive-species, strong external scientific networks, and remarkable tribal awareness of climate change.

Description: To prevent the loss of biodiversity in northern Central America, which is one of 34 global biodiversity hotspots, the Mesoamerican Biological Corridor, a network of protected parks and reserves has been proposed. While on-going deforestation to croplands and pastures outside the protected regions is likely to effect the dry season precipitation over the regenerated and extant forests in the proposed protected regions, global climate change driven precipitation changes may also be a significant factor, at least at some locations. This study compares the effects of land cover change to the effects of elevated greenhouse gas concentrations on precipitation in the proposed areas of the Mesoamerican Biological Corridor network. Using 5 consecutive dry season simulations of the effects of land cover change that included dry, wet and normal years, and using statistically downscaled global climate model (GCM) precipitation from the fourth assessment report (AR4), a larger expanse of the proposed protected regions was found more sensitive to precipitation decreases due to land cover changes. Two specific protected regions however stand out: the Maya Highlands and some areas of the Maya lowlands that were more sensitive to global climate change driven precipitation decreases. In these protected regions it is likely that irrespective of local policies the climate change signal would dominate.

Description: Tribal communities in the United States, particularly in coastal areas, are being forced to relocate due to accelerated rates of sea level rise, land erosion, and/or permafrost thaw brought on by climate change. Forced relocation and inadequate governance mechanisms and budgets to address climate change and support adaptation strategies may cause loss of community and culture, health impacts, and economic decline, further exacerbating tribal impoverishment and injustice. Sovereign tribal communities around the US, however, are using creative strategies to counter these losses. Taking a human rights approach, this article looks at communities’ advocacy efforts and strategies in dealing with climate change, displacement, and relocation. Case studies of Coastal Alaska and Louisiana are included to consider how communities are shaping their own relocation efforts in line with their cultural practices and values. The article concludes with recommendations on steps for moving forward toward community-led and government-supported resettlement programs.

Description: The Nooksack Indian Tribe (Tribe) inhabits the area around Deming, Washington, in the northwest corner of the state. The Tribe is dependent on various species of Pacific salmonids that inhabit the Nooksack River for ceremonial, commercial, and subsistence purposes. Of particular importance to the Tribe are spring Chinook salmon. Since European arrival, the numbers of fish that return to spawn have greatly diminished because of substantial loss of habitat primarily due to human-caused alteration of the watershed. Although direct counts are not available, it is estimated that native salmonid runs are less than 8 % of the runs in the late 1800’s. In addition, climate change has caused and will continue to cause an increase in winter flows, earlier snowmelt, decrease in summer baseflows, and an increase in water temperatures that exceed the tolerance levels, and in some cases lethal levels, of several Pacific salmonid species. The headwaters of the Nooksack River originate from glaciers on Mount Baker that have experienced significant changes over the last century due to climate change. Melt from the glaciers is a major source of runoff during the low-flow critical summer season, and climate change will have a direct effect on the magnitude and timing of stream flow in the Nooksack River. Understanding these changes is necessary to protect the Pacific salmonid species from the harmful effects of climate change. All nine salmonid species that inhabit the Nooksack River will be adversely affected by reduced summer flows and increased temperatures. The most important task ahead is the planning for, and implementation of, habitat restoration prior to climate change becoming more threatening to the survival of these important fish species. The Tribe has been collaboratively working with government agencies and scientists on the effects of climate change on the hydrology of the Nooksack River. The extinction of salmonids from the Nooksack River is unacceptable to the Tribe since it is dependent on these species and the Tribe is place-based and cannot relocate to areas where salmon will survive.

Description: Understanding vulnerability to the impacts of global environmental change and identifying adaptation measures to cope with these impacts require localized investigations that can help find actual and exact answers to the questions about who and what are vulnerable, to what are they vulnerable, how vulnerable are they, what are the causes of their vulnerability, and what responses can lessen their vulnerability. People living in forests are highly dependent on forest goods and services, and are vulnerable to forest changes both socially and economically. In the Congo basin, climate change effects on forest ecosystems are predicted to amplify the existing pressure on food security urging expansion of current agricultural lands at the expense of forest, biodiversity loss and socioeconomic stresses. The paper aimed at exploring vulnerability and adaptation needs to climate change of local communities in the humid forest zone of Cameroon. Field work was conducted in two forest communities in Lekié and in Yokadouma in the Center and Eastern Regions of Cameroon respectively. The assessment was done using a series of approaches including a preparatory phase, fieldwork proper, and validation of the results. Results show that: (a) the adverse effects of climate conditions to which these communities are exposed are already being felt and exerting considerable stress on most of their livelihoods resources; (b) drought, changing seasons, erratic rain patterns, heavy rainfall and strong winds are among the main climate-related disturbances perceived by populations in the project sites; (c) important social, ecological and economic processes over the past decades seemed to have shaped current vulnerability in the sites; (d) Some coping and adaptive strategies used so far are outdated; and specific adaptation needs are identified and suggestions for facilitating their long-term implementations provided.

Description: The national version of FUND3.6 is used to backcast the impacts of climate change to the 20th century and extrapolate to the 21st century. Carbon dioxide fertilization of crops and reduced energy demand for heating are the main positive impacts. Climate change had a negative effect on water resources and, in most years, human health. Most countries benefitted from climate change until 1980, but after that the trend is negative for poor countries and positive for rich countries. The global average impact was positive in the 20th century. In the 21st century, impacts turn negative in most countries, rich and poor. Energy demand, water resources, biodiversity and sea level rise are the main negative impacts; the impacts of climate change on human health and agriculture remain positive until 2100.

Description: “Grand Paris” is a study carried out by ten teams of researchers and city planners in the aim of putting forward general guidelines for Paris urban area’s evolution by 2030. All the teams suggest making the area “greener” in some way, to combat climate warming by CO 2 sequestration. Our team also shows that extending the nearby forests by 30 %, favouring short farm-to-consumer circuits and using lighter coloured building materials will decrease the urban heat island, reducing the mortality during heat waves as well as the need for air-conditioning. These results lead us to reverse the way of thinking urban planning: the geographic and natural aspects should replace the urban infrastructure as a driver for planning urban development. This new strategy allows city changes on quite a large scale, that will have a favourable impact in terms of economics, leisure activities, greenhouse gas emissions and the local microclimate.

Description: This paper addresses deficiencies of stochastic Weather Generators (WGs) in terms of reproduction of low-frequency variability and extremes, as well as the unanticipated effects of changes to precipitation occurrence under climate change scenarios on secondary variables. A new weather generator (named IWG) is developed in order to resolve such deficiencies and improve WGs performance. The proposed WG is composed of three major components, including a stochastic rainfall model able to reproduce realistic rainfall series containing extremes and inter-annual monthly variability, a multivariate daily temperature model conditioned to the rainfall occurrence, and a suitable multi-variate monthly generator to fit the low-frequency variability of daily maximum and minimum temperature series. The performance of IWG was tested by comparing statistical characteristics of the simulated and observed weather data, and by comparing statistical characteristics of the simulated runoff outputs by a daily rainfall-runoff model fed by the generated and observed weather data. Furthermore, IWG outputs are compared with those of the well-known LARS-WG weather generator. The tested characteristics are a variety of different daily statistics, low-frequency variability, and distribution of extremes. It is concluded that the performance of the IWG is acceptable, better than LARS-WG in the majority of tests, especially in reproduction of extremes and low-frequency variability of weather and runoff series.

Description: The assessment of potential impacts of climate change is progressing from taxonomies and enumeration of the magnitude of potential direct effects on individuals, societies, species, and ecosystems according to a limited number of metrics toward a more integrated approach that also encompasses the vast range of human response to experience and risk. Recent advances are both conceptual and methodological, and include analysis of some consequences of climate change that were heretofore intractable. In this article, I review a selection of these developments and represent them through a handful of illustrative cases. A key characteristic of the emerging areas of interest is a focus on understanding how human responses to direct impacts of climate change may cause important indirect and sometimes distant impacts. This realization underscores the need to develop integrated approaches for assessing and modeling impacts in an evolving socioeconomic and policy context.

Description: This paper studies the effects of mitigation and adaptation on coastal flood impacts. We focus on a scenario that stabilizes concentrations at 450 ppm-CO 2 -eq leading to 42 cm of global mean sea-level rise in 1995–2100 (GMSLR) and an unmitigated one leading to 63 cm of GMSLR. We also consider sensitivity scenarios reflecting increased tropical cyclone activity and a GMSLR of 126 cm. The only adaptation considered is upgrading and maintaining dikes. Under the unmitigated scenario and without adaptation, the number of people flooded reaches 168 million per year in 2100. Mitigation reduces this number by factor 1.4, adaptation by factor 461 and both options together by factor 540. The global annual flood cost (including dike upgrade cost, maintenance cost and residual damage cost) reaches US$ 210 billion per year in 2100 under the unmitigated scenario without adaptation. Mitigation reduces this number by factor 1.3, adaptation by factor 5.2 and both options together by factor 7.8. When assuming adaptation, the global annual flood cost relative to GDP falls throughout the century from about 0.06 % to 0.01–0.03 % under all scenarios including the sensitivity ones. From this perspective, adaptation to coastal flood impacts is meaningful to be widely applied irrespective of the level of mitigation. From the perspective of a some less-wealthy and small island countries, however, annual flood cost can amount to several percent of national GDP and mitigation can lower these costs significantly. We conclude that adaptation and mitigation are complimentary policies in coastal areas.