How Five Decades of Land‐Cover Change Reshaped Suitable Habitat for Puerto Rican Tree Species

ABSTRACT Aim Human land‐use has dramatically altered the amount, quality and connectivity of habitat for species worldwide. Understanding how these changes affect individual species is essential for predicting the overall consequences of land‐use change for biodiversity. Location The Caribbean island of Puerto Rico. Forest cover on the island increased from about 18% to 45% from the late 1940's to the early 2000's. Methods Using data on modelled geographic distributions and functional traits for 546 tree species, we evaluated how the gain of modelled potential suitable habitat (i.e., climatically‐suitable and forested) was related to species‐specific climatic associations and life‐history strategies. We estimated species‐specific potential suitable habitat (climatically suitable and forested) with species distribution models and data on land cover. We characterized each species' niche breadth (the range of environmental conditions it occupies) and niche position (the environmental conditions it prefers) to compare with the niche characteristics of reforested lands (i.e., those that changed from nonforest to forest land cover). Results Species with relatively more potential suitable habitat in 1951 also had relatively larger gains in potential suitable habitat from 1951 to 2000. Species that tend to occur in conditions different from those common in reforested areas (i.e., associated with more ‘marginal’ habitats) gained relatively less potential suitable habitat and species with broad environmental niches gained more potential suitable habitat. Niche breadth was weakly associated with changes in connectivity among patches. Main Conclusions Our results show that Puerto Rico's reforestation preferentially increased potential suitable habitat for species that (1) already had suitable habitat in the landscape and (2) tolerate a wide range of climatic conditions. Our findings illustrate how land‐use change in heterogeneous tropical landscapes can generate non‐uniform habitat gains across species, which may favour generalist over specialist species and potentially alter community composition.