Assessing Climate Change Exposure for the Adaptation of Conservation Management: The Importance of Scale in Mountain Landscapes

Vulnerability of mountain ecosystems to climate change depends on the capacity of topographic variation to provide heterogeneous microclimates and rates of climatic change. Accurate methods are therefore needed to assess climate at spatial resolutions relevant to ecological responses and environmental management. Here, we evaluate a mechanistic microclimate model (30 m resolution; Microclima) and mesoclimate data (1 km; CHELSA) against in situ temperatures, finding that both capture (whilst somewhat underestimating) variation well in observed ground-level maxima along a mountain ridge in 2011-13. We apply the models to estimate ecological exposure to recent temperature changes for four mountain areas of the Iberian Peninsula, based on analogous and non-analogous monthly maxima in 1980–1989 versus 2010–2019. The microclimate model revealed fine-resolution exposure to non-analogous conditions that were concealed in mesoclimate data, although whether exposure was greater at the micro- or mesoscale (and hence the types of organisms or management decisions affected) depended on the topographic context of each mountain range. Habitat type influenced microclimatic exposure, and hence may provide opportunities for conservation adaptation. These results suggest that mechanistic models are potentially useful tools to assess exposure to climate change at spatial resolutions that permit understanding and management of biodiversity responses in mountain ecosystems