Integration of community ecology and habitat suitability modelling for restoration and conservation of two endemic tree species from the Western Ghats, India

The recurrent anthropogenic disturbances, poor regeneration potential, high carbon stocks, and restricted habitat suitability warrants effective conservation and restoration of two ecologically and economically important endemic tree species. Despite a growing consensus on the application of species distribution models (SDM) in predicting species distributions, the integration of community ecology of endemic species based on field studies with SDM is largely an isolated area of research. This paper presents a detailed account of the distribution, habitat preferences, population ecology and biomass of two endemic tree species, Terminalia paniculata Roth and Lagerstroemia microcarpa Wt. from 119 (0.1 ha) plots sampled in the Shettihalli landscape of the central Western Ghats, India. MaxEnt SDM was used to predict their distribution by testing the influence of environmental factors. We found a significant difference in the density, basal area and carbon stocks of T. paniculata across the dry and moist deciduous and semi-evergreen forests (p < 0.05). Both species were found to be predominant in moist deciduous forests and contributed high biomass carbon. The regeneration potential of T. paniculata was poor in dry deciduous and semi-evergreen forests, whereas L. microcarpa displayed poor to no regeneration in all the forest types. Further, SDM predicted a high probability of distribution for both species. The main factors driving the occurrence in Shettihalli were land use and land cover, precipitation amount of the driest month, soil pH and elevation. The current high suitability of T. paniculata and L. microcarpa were around 137.66 km2 and 120.49 km2, respectively. Variations in the population structure and regeneration in different forest types are attributed to ongoing anthropogenic disturbances in the landscape. The findings of this study can be extremely helpful in developing proper conservation strategies to protect these species and restore their habitat. We highly recommend the incorporation of SDMs in conservation studies.