COS 209-1 - Vertebrate conservation priorities in the Appalachian Mountains at the interface of climate change and species’ dispersal limitations

Wednesday, August 9, 2023

3:30 PM – 3:45 PM PDT

Location: B117

Presenting Author(s)

NB

Narayani Barve

University of Tennessee
Knoxville, Tennessee, United States

Coauthor(s)

EB

Emily Brook

University of Tennessee, Knoxville, United States
PA

Paul Armsworth

University of Tennessee Knoxville
Knoxville, Tennessee, United States
XG

Xingli Giam

University of Tennessee, Knoxville, United States
MP

Mona Papes

University of Tennessee, United States

Abstract: Background/Question/Methods

Forests of the central and southern Appalachian mountains in the southeastern United States contain a highly biodiverse and highly endemic fauna. Species in this region face an uncertain future given ongoing climate change and other impacts. With a rapidly changing climate, species will need to shift their ranges to track suitable climatic conditions. However, many species may not be able to keep pace with suitable climate conditions because of dispersal limitations. Understanding better the role of dispersal limitation in moderating climate change impacts on Appalachian species is critical for conservation practitioners and other stakeholders when developing their strategies for conservation and management.

To assess whether species can reach the suitable climatic conditions in different future time periods and climate change scenarios, we used an ecological niche modeling approach to model conditions for more than 300 species of amphibians, reptiles, birds, and mammals in the Appalachian region. We estimated the distribution of suitable conditions in the current climate and in the future when assuming four scenarios regarding greenhouse gas emissions, six different time periods and four global circulation models. To understand the role of dispersal limitation, we compiled dispersal estimates for the species from literature. We used these estimates to evaluate whether the dispersal capacity of species is sufficient to allow them to reach future climatically suitable areas as these shift through time. We compared our predictions about future range sizes for species that were based on species-specific dispersal estimates with predictions that one would arrive at if adopting two commonly used alternative assumptions, either no dispersal or unlimited dispersal.

Results/Conclusions

Our results suggest that highly endemic species with limited dispersal capacity are highly vulnerable to climate change, and that these species might need a different conservation strategy altogether compared to species that can disperse farther to track suitable climates. Some large-scale patterns are clear with species moving upslope and to more northerly latitudes. At the same time, the complex geography of the region also implies that there can be large uncertainty in some parts of the landscape over future patterns of species richness. Our results also show that species that are predicted in our models to face large range reductions under future climate change are doubly impacted when we also consider projected changes to habitat cover in the region. In conclusion, we suggest that consideration of dispersal limitation is an important factor for conservation in changing climatic scenarios.