Abstract
AbstractAimUnderstanding the forces shaping biodiversity patterns, particularly for groups of organisms with key functional roles, will help predict the responses of ecosystems to environmental changes. Our aim was to evaluate the relative role of different drivers in shaping the diversity patterns of vertebrate herbivores, a group of organisms exerting a strong trophic influence in terrestrial Arctic ecosystems. This biome, traditionally perceived as homogeneous and low in biodiversity, includes wide variation in biotic and physical conditions and is currently undergoing major environmental change.LocationThe Arctic (including the High Arctic, Low Arctic and Subarctic)MethodsWe compiled available data on vertebrate (birds and mammals) herbivore distribution at a pan‐Arctic scale, and used eight variables that represent the most relevant hypotheses for explaining patterns of species richness. We used range maps rasterized on a 100 km × 100 km equal‐area grid to analyse richness patterns of all vertebrate herbivore species combined, and birds and mammalian herbivores separately.ResultsOverall, patterns of herbivore species richness in the Arctic were positively related to plant productivity (measured using the normalized difference vegetation index) and to the species richness of predators. Greater species richness of herbivores was also linked to areas with a higher mean annual temperature. Species richness of avian and mammalian herbivores were related to the distance from the coast, with the highest avian richness in coastal areas and mammalian richness peaking further inland.Main conclusionsHerbivore richness in the Arctic is most strongly linked to primary productivity and the species richness of predators. Our results suggest that biotic interactions, with either higher or lower trophic levels or both, can drive patterns of species richness at a biome‐wide scale. Rapid ongoing environmental changes in the Arctic are likely to affect herbivore diversity through impacts on both primary productivity and changes in predator communities via range expansion of predators from lower latitudes.
Highlights
Biodiversity plays a key role in maintaining the stability of ecosystems facing anthropogenic environmental changes (Hautier et al, 2015)
Our analysis of overall patterns of herbivore species richness represents the first attempt to identify the drivers of diversity of a main trophic group across the Arctic biome
We found strong support for the species-energy hypothesis and for the role of biotic interactions in shaping herbivore diversity at a pan-Arctic scale, with greater herbivore species richness in areas presenting the highest Normalized Difference Vegetation Index (NDVI) and predator richness values
Summary
Biodiversity plays a key role in maintaining the stability of ecosystems facing anthropogenic environmental changes (Hautier et al, 2015). In addition to the role of evolutionary processes and species dispersal, current biodiversity patterns are strongly determined by environmental constraints. Understanding what shapes patterns of biodiversity, for groups of organisms with key functional roles in ecosystems, will improve predictions about the responses of ecosystems to ongoing environmental changes. Despite recent attempts to document biodiversity and to anticipate the effects of rapid and unprecedented change in the Arctic (e.g. CAFF, 2013), analyses of diversity patterns and especially of their drivers are still lacking for this region. Given the relative simplicity of arctic food webs and the extreme abiotic conditions, the Arctic has been proposed as a model for understanding the interactions between biotic and abiotic elements in ecosystem functioning. As a temperature-limited system that is rapidly warming due to climate change, the Arctic may be regarded as a bellwether for the changes to come in other systems (Post et al, 2009)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
