Landscape fragmentation affects responses of avian communities to climate change

Abstract

Forecasting the consequences of climate change is contingent upon our understanding of the relationship between biodiversity patterns and climatic variability. While the impacts of climate change on individual species have been well-documented, there is a paucity of studies on climate-mediated changes in community dynamics. Our objectives were to investigate the relationship between temporal turnover in avian biodiversity and changes in climatic conditions and to assess the role of landscape fragmentation in affecting this relationship. We hypothesized that community turnover would be highest in regions experiencing the most pronounced changes in climate and that these patterns would be reduced in human-dominated landscapes. To test this hypothesis, we quantified temporal turnover in avian communities over a 20-year period using data from the New York State Breeding Atlases collected during 1980-1985 and 2000-2005. We applied Bayesian spatially varying intercept models to evaluate the relationship between temporal turnover and temporal trends in climatic conditions and landscape fragmentation. We found that models including interaction terms between climate change and landscape fragmentation were superior to models without the interaction terms, suggesting that the relationship between avian community turnover and changes in climatic conditions was affected by the level of landscape fragmentation. Specifically, we found weaker associations between temporal turnover and climatic change in regions with prevalent habitat fragmentation. We suggest that avian communities in fragmented landscapes are more robust to climate change than communities found in contiguous habitats because they are comprised of species with wider thermal niches and thus are less susceptible to shifts in climatic variability. We conclude that highly fragmented regions are likely to undergo less pronounced changes in composition and structure of faunal communities as a result of climate change, whereas those changes are likely to be greater in contiguous and unfragmented habitats.

Synergistic effects of climate and land cover: grassland birds are more vulnerable to climate change

“…However, two of the grassland species considered in our study-Bobolink and Eastern kingbird-had relatively expansive distributions, occupying approximately 64 and 82 % of all BBA1980 blocks, respectively, and yet their responses to increasing temperatures were some of the strongest across all birds. Thus, we suggest that the width of the habitat and climatic niches-though plausible in other species and ecosystems (Jarzyna et al 2015)-is an unlikely cause of the differential responses of forest and grassland birds to climate change in our system. Finally, the observed differences between forest and grassland birds might be a result of species biogeographical history rather than differences in microclimates of forest and grassland habitats (Clavero et al 2011;Barnagaud et al 2013Barnagaud et al , 2014.…”

“…Birds selected for our study breed in a suite of different forest types and have relatively large geographic distributions [their occurrence ranges from 7.0 to 91.0 % (mean 46 %) of all BBA blocks], suggesting that their climatic niches are also relatively wide (Barnagaud et al 2012). Species with wider climatic niches could potentially tolerate greater changes in climatic conditions and thus respond weakly to climate change (Jarzyna et al 2015). However, if the breadth of climatic niche was responsible for the observed weak responses of forest birds to climate change, then the same would be expected of grassland birds, provided that grassland birds were as extensively distributed as forest birds.…”

“…In simulation studies, habitat loss has been shown to reduce species ability to adjust to changing climatic conditions and thus exacerbate the detrimental effects of climate change (Travis 2003), while an increase in the amount of suitable land cover has been shown to reduce species extinction rates (Jeltsch et al 2011). Empirical evidence, however, is lacking because studies that integrate both kinds of impacts (land cover and climate) remain rare (but see Kampichler et al 2012;Jarzyna et al 2015). Gaining a better understanding of the synergistic effects of climate change and land cover will provide a deeper understanding of which species are more or less vulnerable to climate change.…”

Thermal Characterization of European Ant Communities Along Thermal Gradients and Its Implications for Community Resilience to Temperature Variability

“…For instance, Princé and Zuckerberg (2015) analyzed the changes that took place over a 22-year period in winter bird communities in North America, and they found that bird communities at southern latitudes were the most affected by climatic variability. Jarzyna et al (2015) found that bird communities in fragmented landscapes are less vulnerable to climate change than communities found in homogenous habitats, probably due to the fact that they are comprised of species with wider thermal niches and are less susceptible to shifts in climatic variability. We found that community thermal breadth depends on, independently, both mean thermal breadth (i.e., the average of the species-specific thermal responses found in a community) and community thermal complementarity (i.e., the complementarity of those species-specific thermal responses).…”

“…This is because species do not usually live in isolation; instead, they form communities where they interact with each other, and often species respond to environmental changes as a group. More recently, several studies have examined community responses to climate change (Devictor et al, 2008;Kampichler et al, 2012;Lindström et al, 2013;Jarzyna et al, 2015;Nieto-Sánchez et al, 2015;Princé and Zuckerberg, 2015); nonetheless, our understanding of how climate change affects community-level biodiversity remains incomplete. Moreover, previous studies have focused on the alarming expected increase in global mean temperature.…”