Doutoramento em Biologia
Synergistic effects of climate change and habitat fragmentation on species range shifts and metapopulation persistence
Frederico Manuel Vaz Pontes Vitorino Mestre

Orientação : António Mira, Ricardo Pita & Pedro Beja

The effects of climate and landscape change on biodiversity have been widely acknowledged. However, there is still limited understanding on how the interaction among these processes affects species persistence over large spatial scales. This thesis aims to study the synergistic effects of climate and landscape change on species persistence and range shift dynamics. Using the Cabrera vole as model species, and combining ecological niche modeling (ENM), non-invasive genetic analysis and field sampling at predicted range margins, it is shown that forecasting range shifts of metapopulations under climate change, should require detailed sampling at the extremes of the ecological niche and that combining these three techniques allows na effective assessment of the niche. Analysis of metapopulation persistence and range expansion under landscape and climate change involved the development of an R package, ‘MetaLandSim’. This package offers a set of simulation tools integrating concepts from metapopulation and graph theories, providing an opportunity for testing ecological theories and evaluating species responses to environmental change.

A first example of the package use is demonstrated by combining ENM projections with dispersal models (DM) considering three different connectivity scenarios. It is clearly demonstrated that combining range shift with lower connectivity will result in narrower range sizes for the Cabrera vole, highlighting the relevance of both, climate change and landscape connectivity in range dynamics evaluation. Finally, ‘MetaLandSim’ was used to test the hypothesis that intermediate levels of landscape disturbance may increase species persistence under certain species and landscape traits. Using a set of 54 virtual species differing in their ecological traits, it is shown that species with mid to higher dispersal and early successional preferences were more likely to benefit from intermediate disturbance. Overall, this study provides importante insights for improving predictions on metapopulation persistence and range Dynamics under various scenarios of landscape and climate change.

Keywords: Metapopulation persistence, ecological niche modelling, landscape change, climate, range shift.