Future Climate Change May Reduce Suitable Habitat for the Timber Tree Gmelina arborea

Abstract

Populations of Gmelina arborea (Lamiaceae), a fast-growing deciduous tree widely used in afforestation, agroforestry and timber production, and valued for carbon sequestration and land rehabilitation, are declining across parts of its range due to escalating anthropogenic pressure and climate-driven environmental change. As large-scale planting and restoration programmes increasingly rely on this species, identifying areas where climate conditions will remain suitable is essential for climate-smart site selection and long-term plantation viability. We applied species distribution modelling to quantify the current and projected habitat suitability of G. arborea under present and future climatic conditions proxied through several Shared Socioeconomic Pathways climate change scenarios. We used the low-resolution global climate model by the Institut Pierre-Simon Laplace Climate Modelling Centre, Version 6A, to simulate future climate conditions for the year 2050 across the eastern Indian state Jharkhand. At present, approximately 38% of Jharkhand's area provides suitable habitat for the species; however, projections indicate that this may decline to 17-40% by 2050, depending on the Shared Socioeconomic Pathways scenario. Precipitation of the driest month and mean temperature of the driest quarter were the most influential predictors, indicating that the species is probably highly sensitive to moisture deficits and seasonal climatic extremes that regulate establishment and growth. These results provide a scientific basis for climate-informed management strategies, including targeted site selection, assisted dispersal, and silvicultural interventions, to sustain future restoration and farm forestry initiatives involving G. arborea in vulnerable tropical landscapes.