Laura Moro: Caribbean forests in a changing landscape: Effects of land-use change on habitat availability, abundance, and genetic diversity of tropical trees

Abstract

Land-use change is a major driver of biodiversity loss in tropical forests, yet its impacts on species distributions, population dynamics, and genetic diversity remain poorly understood. Using Puerto Rico as a model system, this thesis integrates species distribution modelling, abundance data, and comparative population genetics to assess how historical habitat loss and forest regrowth have shaped tropical tree species’ distributions, population sizes, and genetic diversity.

The first paper quantifies changes in potential suitable habitat amount and configuration for 454 tree species and relates these changes to species’ life-history strategies. The second paper examines how shifts in habitat amount and configuration are associated with contemporary abundance for 108 tree species. The third paper presents a comprehensive genetic dataset for 19 focal tree species, including population genetic markers, phenotypic traits, and geographic distribution data, providing a foundation for comparative analyses. Building on this dataset, the fourth paper investigates genetic signatures associated with forest loss and subsequent regrowth, and identifies the main ecological and life-history drivers shaping species genetic diversity.

Overall, land-use change affects species differently, with specialist and generalist species as well as species with contrasting life-history strategies showing divergent responses. Species with acquisitive life-history traits tend to exhibit stronger and faster responses in terms of habitat gain, abundance, and genetic diversity, whereas species with conservative traits show more lagged effects. This thesis highlights the importance of integrating landscape history, species traits, and genetic data to better understand long-term biodiversity responses and resilience potential to anthropogenic land-use change in tropical forests.