The shifting balance between habitat and climate drivers of boreal biodiversity across space and taxa

Abstract Changes in land use and climate pose major threats to biodiversity 1–5 . However, variation in species responses to climate and land use across space, time, and taxa remains poorly understood 3,6–10 , hindering our ability to predict and mitigate biodiversity change. Here, we evaluate the relative importance of concurrent changes in climate and land use in driving the occurrence and abundance patterns of 503 terrestrial animal species of various taxa over 20 years in Finland. Habitat composition proved to be the main driver of biodiversity patterns but how much and with what uncertainty it explained species distributions depended highly on the context. Specifically, habitat was the dominant driver for butterflies, birds, and small mammals, while habitat and climate were equally important for large mammals and moths. Additionally, species patterns between biogeographical regions were mainly explained by climate, while habitat was the main driver within regions. Traits, such as, body size, pace of life, habitat and diet specialization modulated the relative importance of both drivers’ impacts. Climate and habitat impact on most species were also partially correlated, highlighting the tight connection between the drivers. Our findings emphasize that land use is a major force in shaping terrestrial biodiversity, while highlighting its tight connection with climate. Considering functional and spatial contexts is thus essential for building effective management and conservation strategies for biodiversity under rampant global change.