Abstract
Organisms require specific thermal conditions (their thermal niche) in order to live,however climate change is altering both the mean and range of temperatures
present in a landscape, as well as the arrangement of these across space and time.
This is causing biodiversity to decline, threatening the proper functioning of vital
ecosystem services. Global warming in particular has complex and multifaceted
impacts on ecosystem structure and dynamics due to its influence over both
individuals and species interactions. Because of the role thermal niche plays in
habitat selection, temperature heterogeneity and environmental autocorrelation
interact with dispersal to influence population dynamics. However, despite much
research on the fate of meta-populations in the face of increasingly heterogeneous
environments, the effect of this, and specifically its spatial structuring, on
metacommunity diversity is so far unknown. Moreover, the spatiotemporal
arrangement of environmental heterogeneity interacts with other factors, notably
here dispersal, to influence the response of a system to environmental change.
In the first chapter, I review the literature on this topic, discussing the mechanisms
behind how climate change might impact metacommunities, and suggest ways to
explore these issues using metacommunity modelling. In the second chapter, I
present a spatially explicit metacommunity model, which investigates the effect of
these variable parameters on a multi-trophic, 10-species system, with
temperaturedependent dispersal, in the presence of environmental warming. I found
that only heterogeneity significantly influences landscape level Shannon diversity at
the final time point. All three variable parameters included in the model (spatial
autocorrelation, temporal autocorrelation, and temperature heterogeneity), as well as
the interaction between temporal autocorrelation and temperature heterogeneity,
significantly influenced the variation in diversity present across the landscape at the
end of the simulation. The final chapter presents an overview of the project, including
a discussion of the limitations and future directions of this research.
| Date of Award | 18 Mar 2025 |
|---|---|
| Original language | English |
| Awarding Institution |
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| Supervisor | Chris F Clements (Supervisor) & Martin De Kauwe (Supervisor) |