ALBERT

Description: The influence of climate change on the fitness of wild populations is often studied in the context of the spring onset of the reproductive season. This focus is relevant for climate influences on reproductive success, but neglects other fitness-relevant periods (e.g., autumn preparation for overwintering). We examined variation in climate variables (temperature, rainfall, snowfall, and snowpack) across the full annual cycle of Columbian ground squirrels ( Urocitellus columbianus ) for 21 years. We investigated seasonal climate variables that were associated with fitness variables, climate variables that exhibited directional changes across the study period, and finally observed declines in fitness (−0.03 units/year; total decline = 37%) that were associated with directional changes in climate variables. Annual fitness of adult female ground squirrels was positively associated with spring temperature ( r  =   0.69) and early summer rainfall ( r  =   0.56) and negatively associated with spring snow conditions ( r  =   −0.44 to −0.66). Across the 21 years, spring snowmelt has become significantly delayed ( r  =   0.48) and summer rainfall became significantly reduced ( r  =   −0.53). Using a standardized partial regression model, we found that directional changes in the timing of spring snowmelt and early summer rainfall (i.e., progressively drier summers) had moderate influences on annual fitness, with the latter statistically significant ( ρ  = −0.314 and 0.437, respectively). The summer period corresponds to prehibernation fattening of young and adult ground squirrels. Had we focused on a single point in time (viz. the onset of the breeding season), we would have underestimated the influences of climate change on our population. Rather, we obtained a comprehensive understanding of the influences of climate change on individual fitness by investigating the full lifecycle. Seasonal climate variables influence fitness in Columbian ground squirrels. Snow melt-off in spring has gotten later in the past 21 years, and early summer rainfall has become sparser. Both climate variables had significant negative influences on annual fitness, although the latter was a slightly stronger influence.

Description: Home range (HR) size variation is often linked to resource abundance, with sex differences expected to relate to sex-specific fitness consequences. However, studies generally fail to disentangle the effects of the two main drivers of HR size variation, food and conspecific density, and rarely consider how their relative influence change over spatiotemporal scales. We used location data from 77 Eurasian lynx ( Lynx lynx ) from a 16-year Scandinavian study to examine HR sizes variation relative to prey and conspecific density at different spatiotemporal scales. By varying the isopleth parameter (intensity of use) defining the HR, we show that sex-specific effects were conditional on the spatial scale considered. Males had larger HRs than females in all seasons. Females' total HR size declined as prey and conspecific density increased, whereas males' total HR was only affected by conspecific density. However, as the intensity of use within the HR increased (from 90% to 50% isopleth), the relationship between prey density and area showed opposing patterns for females and males; for females, the prey density effect was reduced, while for males, prey became increasingly important. Thus, prey influenced the size of key regions within male HRs, despite total HR size being independent of prey density. Males reduced their HR size during the mating season, likely to remain close to individual females in estrous. Females reduced their HR size postreproduction probably because of movement constrains imposed by dependent young. Our findings highlight the importance of simultaneously considering resources and intraspecific interactions as HR size determinants. We show that sex-specific demands influence the importance of prey and conspecific density on space use at different spatiotemporal scales. Thus, unless a gradient of space use intensity is examined, factors not related to total HR size might be disregarded despite their importance in determining size of key regions within the HR. Since food and conspecific density are often strongly correlated in natural systems few studies have been able to simultaneously assess the effect of these two factors on individual spacing behavior. Using a long term and large scale location dataset from Eurasian lynx we show that sex-specific needs influenced the importance of prey and conspecific density as home range (HR) size determinants. Furthermore, unless different spatiotemporal scales are examined, factors not related to total HR size might be disregarded as determinants of animal spatial ecology despite their importance for the size of key regions within the animal's HR.

Description: Although the effects of individual age, resource availability, and reproductive costs have been extensively studied to understand the causes of variation in reproductive output, there are almost no studies showing how these factors interact in explaining this variation. To examine this interaction, we used longitudinal demographic data from an 18-year study of 53 breeding female wolverines ( Gulo gulo ), and corresponding environmental data from their individual home ranges. Females showed a typical age-related pattern in reproductive output, with an initial increase followed by a senescent decline in later years. This pattern was largely driven by four processes: (1) physiological/behavioral maturation between ages two and three; (2) age-related differences in the costs of reproduction resulting in an initial increase, and then a declining probability of breeding two years in a row as individuals aged; (3) resource availability (reindeer [ Rangifer tarandus ] carcass abundance; mostly Eurasian lynx [ Lynx lynx ] kills) in the months preceding parturition, which influenced the probability of having cubs, but only for individuals that had successfully bred in the previous year; and (4) resource availability also influenced the cost of reproduction in an age-dependent manner, as prime age females that had bred in the previous year were more responsive to resource availability than those at other ages. This study demonstrates that by examining how drivers of reproductive variation interact, we can get a much clearer understanding of the mechanisms responsible for age-related patterns of reproduction. This has implications not only for general ecological theory, but will also allow better predictions of population responses to environmental changes or management based on a population's age-structure.

Description: Ecological diversification depends on the extent of genetic variation and on the pattern of covariation with respect to ecological opportunities. We investigated the pattern of utilization of carbon substrates in wild populations of budding yeast Saccharomyces paradoxus . All isolates grew well on a core diet of about 10 substrates, and most were also able to grow on a much larger ancillary diet comprising most of the 190 substrates we tested. There was substantial genetic variation within each population for some substrates. We found geographical variation of substrate use at continental, regional, and local scales. Isolates from Europe and North America could be distinguished on the basis of the pattern of yield across substrates. Two geographical races at the North American sites also differed in the pattern of substrate utilization. Substrate utilization patterns were also geographically correlated at local spatial scales. Pairwise genetic correlations between substrates were predominantly positive, reflecting overall variation in metabolic performance, but there was a consistent negative correlation between categories of substrates in two cases: between the core diet and the ancillary diet, and between pentose and hexose sugars. Such negative correlations in the utilization of substrate from different categories may indicate either intrinsic physiological trade-offs for the uptake and utilization of substrates from different categories, or the accumulation of conditionally neutral mutations. Divergence in substrate use accompanies genetic divergence at all spatial scales in S. paradoxus and may contribute to race formation and speciation. Ecological diversification depends on the extent of genetic variation and on the pattern of covariation with respect to ecological opportunities. We investigated the pattern of utilization of carbon substrates in wild populations of budding yeast Saccharomyces paradoxus .

Description: Abstract Industrial symbiosis (IS) employs a cross‐organizational perspective to seek synergistic pairings of one company's waste output to another company's input, enabled by interfirm cooperation through resource and information sharing. Orchestrating IS relationships among companies, however, remains a complex process. In the literature, a wide range of qualitative and quantitative tools have emerged, tackling issues ranging from identifying IS creation opportunities to performance evaluation. Thus far, the available literature has focused on separate aspects and perspective of IS creation. Each individual work contributes, in part, to the overall process of IS creation. The disparate perspectives provided by the literature reflect the fragmented nature of available tools supporting IS, which operate in isolation of each other. An encompassing view of tools supporting the process of IS creation is missing to date. Therefore, to fill this gap, this study aims to develop a more comprehensive description of the landscape of IS tools by analyzing the associated approaches, roles, and contribution of existing tools. Through this understanding, the insights gained can be used to aid future development and advancement of tools for IS practitioners.

Description: Plant functional traits are indicators of ecological strategies. Along environmental gradients, the optimal strategy is likely to change, resulting in different traits being expressed. We measured grass functional traits along a precipitation gradient. High specific leaf area (SLA) species dominated wet sites, but most species expressed highest SLA at dry sites. Other traits showed more congruent among‐ and within‐species patterns. Abstract Questions California's grasslands are heavily invaded by exotic species. Counteracting these invasions depends on understanding the functional differences between native and exotic species and how these shift along environmental gradients. Focusing on grasses, we ask: (a) how native and exotic trait means and intraspecific trait variation (ITV) differ; (b) how the functional composition of grass assemblages shifts with precipitation; and (c) how species shift their functional strategies as precipitation changes. Location Marin County, California (USA). Methods In spring 2017, we censused grassland vegetation plots across eight reserves in Marin County that are arrayed along a precipitation gradient. At each plot, we measured traits of grasses, including height, leaf area and specific leaf area (SLA). Results We found modest differences in functional traits between native and exotic species. Exotic species had larger seeds and higher SLAs, indicating higher reproductive investments and a leaf strategy focused on obtaining rapid returns on investments with relatively short leaf life spans. Native and exotic species did not differ in the ITV for any of the measured traits. Variation in precipitation among sites drove strong turnover in the functional trait composition of grasses, as well as shifts within species. Wetter sites had shorter species with smaller leaf areas, smaller seeds and higher leaf N concentrations. There was also strong intraspecific SLA variation along the precipitation gradient; all species displayed lower SLA values as precipitation increased. Conclusions Consistent with previous results, native species had more conservative leaf strategies. Grasses that display these conservative strategies tend to be more abundant in dry climates, leading to increasing exotic abundance in wetter climates. However, each species shifted towards more conservative strategies as precipitation increased, suggesting that the factors that drive species turnover and ITV differ.

Description: Group formation reduces individual predation risk when the proportion of prey taken per predator encounter declines faster than the increase in group encounter rate (attack-abatement). Despite attack-abatement being an important component of group formation ecology, several key aspects have not been empirically studied, that is, interactions with the hunting mode of the predator and how these relationships are modified by local habitat quality. In 79 cage trials, we examined individual egg predation risk in different-sized egg clutches from the blue willow beetle Phratora vulgatissima for two predators with different hunting modes (consumption of full group [ Orthotylus marginalis ] vs. part group [ Anthocoris nemorum ]). Because these predators also take nutrients from plant sap, we could examine how the quality of alternative food sources (high- vs. low-quality host plant sap) influenced attack-abatement patterns in the presence of different hunting strategies. For the O. marginalis predator, individual egg predation risk was largely independent of group size. For A. nemorum , egg predation risk clearly declined with increasing group size. However, approximately one-third of the grouping benefit was lost to an increase in group detectability. There were clear differences in attack-abatement patterns between plants with high- vs. low-quality sap. When O. marginalis was the predator, there was no clear change in attack-abatement in relation to host plant quality. However, for A. nemorum there was a clear reduction in overall predation risk and a stronger attack-abatement pattern with increasing group size when plant sap quality increased. This implies that the relative benefits of prey grouping behavior for any species might show diurnal or seasonal changes as other aspects of resource/habitat quality change for the focal predator. Modulation of attack-abatement by bottom-up effects such as plant-based food resources is yet to be incorporated into general theory, despite the ubiquity of omnivorous predators and with omnivory being important for shaping food webs, ecosystem functions, and in biological control. Thus, ongoing refinement of attack-abatement theory by focusing on bottom-up vs. top-down processes could have significant impacts on many important contemporary fields of study.

Description: To help mitigate large wetland losses in California, The Nature Conservancy launched a dynamic conservation incentive program to create temporary wetland habitats in harvested and fallow rice fields for shorebirds migrating along the Pacific Flyway. Farmers were invited to participate in a reverse auction bidding process and winning bids were selected based on their cost and potential to provide high quality shorebird habitat. This was done in 2014 and 2015, for separate enrollment periods that overlapped with spring and fall migration, both before and after the traditional post-harvest flooding period. To assess the success of the program we monitored shorebird use of fields that were enrolled (treatments), and others that were subject to typical rice farm management (controls). To put these observations in context, we used satellites to simultaneously monitor the extent of shallow-water habitat across the ~215,000 hectares of ricelands in the area. Results showed that providing habitat during migration, when it is typically unavailable in rice fields, yielded the largest average shorebird densities ever reported for agriculture in the region. Treatment fields had significantly greater shorebird density, richness and diversity than control fields in both spring and fall (especially September – early October, and late March – early April), but in fall the difference was greater. Shorebird responses to habitat provisioning, and regional habitat conditions, were variable from year to year, and highly dynamic within a given season. Overall, shorebirds densities were found to be negatively related to the total amount of flooded habitat in the rice landscape. Factors that affected habitat availability included allocation schedules of water deliveries from reservoirs, and rainfall patterns, both of which were influenced by drought. Collectively, these results suggest that appropriately managed agricultural lands have great potential to provide high value habitat for shorebirds during times of habitat deficit, including migration, and that fall may be a particularly impactful time to create additional habitat. Migratory species face great challenges due to the climate change, conversion of historical stopover sites, and other factors, but dynamic conservation programs offer promise that, at least in certain instances, their needs can still be met. This article is protected by copyright. All rights reserved.

Description: The equations used to account for the temperature dependence of biological processes, including growth and metabolic rates, are the foundations of our predictions of how global biogeochemistry and biogeography change in response to global climate change. We review and test the use of 12 equations used to model the temperature dependence of biological processes across the full range of their temperature response, including supra- and suboptimal temperatures. We focus on fitting these equations to thermal response curves for phytoplankton growth but also tested the equations on a variety of traits across a wide diversity of organisms. We found that many of the surveyed equations have comparable abilities to fit data and equally high requirements for data quality (number of test temperatures and range of response captured) but lead to different estimates of cardinal temperatures and of the biological rates at these temperatures. When these rate estimates are used for biogeographic predictions, differences between the estimates of even the best-fitting models can exceed the global biological change predicted for a decade of global warming. As a result, studies of the biological response to global changes in temperature must make careful consideration of model selection and of the quality of the data used for parametrizing these models. We review and test the use of 12 equations that model the temperature dependence of biological processes across the full range of their temperature response, including supra- and suboptimal temperatures. When rate estimates from these equations are used for biogeographic predictions, differences between the estimates of even the best-fitting equations can exceed the global biological change predicted for a decade of global warming. As a result, studies of the biological response to global changes in temperature must make careful consideration of model selection and of the quality of the data used for parametrizing these models.