A framework for assessing geomorphic control on habitat patch isolation and transience

Landscape evolution continuously reshapes habitat availability, heterogeneity, and connectivity, thereby influencing patterns of biodiversity, endemism, and ecosystem resilience. Over geological timescales, surface processes such as uplift, erosion, and river capture generate spatially complex mosaics of habitats, while simultaneously creating barriers that isolate populations and alter connected pathways. Despite their central role in structuring ecological patterns, local geomorphic controls are rarely quantified explicitly in biodiversity analyses. Here, we present a framework to quantify how geomorphic processes shape habitat, isolation, and transience. The framework is applied across contrasting geomorphic and climatic settings, including the tropical Andes (Puracé National Natural Park, Colombia), a volcanic oceanic island (Gran Canaria, Canary Islands, Spain), and tectonically active arid mountain landscapes (California, USA).

We derived landform-based habitat patches by integrating multi-scale topographic position index classes and slope to explicitly capture the imprint of long-term surface processes and incorporated temperature and water-balance variables (CHELSA) to approximate the climatic constraints of the landscape. Vegetation was evaluated using an independent, remote-sensing–based product, derived by clustering multispectral imagery, vegetation indices, and canopy height. The landform-based habitat patches and remote-sensing-based vegetation product were verified using an official vegetation map from each region as independent biological reference. The isolation of the habitat patch classes is quantified from spatial connectivity using geomorphic barriers such as valleys, rivers, and relief contrasts, while habitat patch transience is explored using activity-related geomorphic indicators that capture ongoing landscape reorganization.

By evaluating geomorphology–vegetation relationships across multiple regions, the framework uses isolation and transience metrics to distinguish stable habitat patches that constrain vegetation distribution from dynamically reorganizing patches that promote fragmentation and turnover. Preliminary analyses indicate that vegetation diversity, based on vegetation maps, within geomorphic habitat patches tends to be lower than regional diversity, suggesting that they capture a meaningful ecological structure. Association strength appears to increase with elevation, pointing to a potentially important role of climate–topography coupling. Using this approach the framework can assess habitat fragmentation and dynamics within a region, serving as a proxy for tectono-geomorphic influences on biodiversity.