Forecasting the impact of climate change on Kalappia celebica distribution: current insights and conservation recommendations

This is the authors' abstract. We don't add key points for this paper.

Kalappia celebica Kosterm is a vulnerable tree species endemic to Sulawesi, threatened by illegal harvesting and further challenged by climate change through potential shifts in temperature and precipitation that may reduce suitable habitats. This study aims to assess the species' potential distribution under current and future climates and evaluate the extent to which suitable habitats overlap with protected areas in South and Southeast Sulawesi. Ensemble modeling through aggregating outputs of three machine learning algorithms: Random Forest (RF), Support Vector Machine (SVM) and Multivariate Adaptive Regression Splines (MARS) was used to predict current and future suitable areas of the species. Geospatial analysis was used to identify the protected areas that overlapped with potential habitats of the species. The ensemble model classification of suitable to highly suitable habitat decreased about 671 km 2 in the year 2100. Current areas classified as suitable to very suitable habitat are found mostly outside of protected areas (97.44%), while 2.56% are located within protected areas. A predictive map for the year 2100 classified 96.46% of the suitable to highly suitable habitat outside of protected areas and 3.54% within protected areas. The predominance of suitable habitat outside of protected areas represents a risk to long-term sustainability. The current and future suitable areas can be found in Pegunungan Faruhumpenai Nature Reserve, Rawa Aopa Watumohai, Mangolo Nature Tourism Park, Lamedae Nature Reserve, Lejja Nature Tourism Park, Murhum Community Forest Park. These findings indicate that most of K. celebica 's potential habitat remains outside protected areas, which poses a significant long-term risk to the species' persistence. This emphasizes the necessity of incorporating these habitats into formal conservation frameworks, while also considering restoration and connectivity measures to enhance resilience under future climate change scenarios.