Projected Habitat Suitability and Climate Refugia of Native Species: Implications for Regional Planning in South-West Victoria, Australia

Context: Climate-driven shifts in habitat suitability can differ substantially among species, complicating the identification of areas likely to retain conservation value through time. Spatially explicit assessment of persistent suitability across multiple species can help identify climate refugia at landscape scales relevant to regional conservation planning. Objectives: The study aims to: (1) Project changes in habitat suitability for four indicator plant species across the Corangamite Catchment, south-eastern Australia, under climate change, and (2) identify areas of persistent multi-species habitat suitability as potential climate refugia . Methods: Habitat suitability and climate refugia were modelled for Allocasuarina verticillata, Themeda triandra, Pimelea spinescens and Eucalyptus ovata, in the Corangamite Catchment using MaxEnt. Suitability was studies in baseline conditions (1970-2000) and future climate scenarios till 2100. Results: Projected responses differ markedly among species. Compared to the baseline habitat distribution of species: Allocasuarina verticillata unsuitable area declined by 78% 2061–2080, due to shift in seasonal precipitation. Very high suitable habitats of Themeda triandra expanded by 200%, in 2061-2080. Pimelea spinescens showed redistribution, with moderate suitability increased by 298% by 2081-2100. High suitability areas of Eucalyptus ovata declined by 79%, by 2081-2100. Multi-species refugia were concentrated in the north-eastern catchment, where three to four species retain stable habitat. Areas where all four species overlap were rare and highly localised, representing the most critical spatial targets for conservation investment. Conclusions: Contrasting habitat suitability and refugia of species demonstrates the value of spatially explicit SDMs in decision making. The transferable workflow support conservation planning across species and catchments.