A genetics-based Universal Community Transfer Function for predicting the impacts of climate change on future communities

Although the genetics of foundation plant species is known to be important drivers of biodiversity and community structure, and climate change is known to have ecological and evolutionary consequences for plants, no studies have integrated these concepts. Here we examine how their combined effects are likely to affect the diversity of future communities. We draw on several complimentary fields (community ecology, landscape genetics and biogeography) to model how climate change will alter productivity of foundation plant species and their associated communities. We focus on three issues: (i) genetic variation of foundation species influences community diversity; (ii) gene-by-environment interactions define associated communities; and (iii) relationships between productivity and species diversity follow predictable patterns. For many foundation species, responses to climate are population specific because populations are often genetically differentiated and locally adapted. Thus, biological models that examine the effects of climate change on species distribution, forest productivity, community structure or function, should incorporate population effects. Our genetics-based Universal Community Transfer Function (UCTF) provides a method to integrate climate-based population differences into community diversity models. Several major findings emerged: (i) using the UCTF, we found that genetics-based differences between populations play an important role in defining future communities. (ii) The shape of the productivity/diversity relationship (e.g. humpbacked versus linear) dramatically affects future communities making it essential to quantify this relationship. (iii) Climate change will impact the community differently at leading, continuous and rear edges of a species' distribution, but diversity at the rear edge will suffer most. Genetics-based approaches are important to understand the ecological and evolutionary consequences of climate change on future communities and ecosystems. Such modelling can assist in identifying populations of foundation species of special value based on their sensitivity to climate change, future biodiversity and potential to support high biodiversity with assisted migration.