Impact of Global Climate Change in the Distribution and the Range Dynamics of Endemic Orchid Habenaria suaveolens Dalzell in Northern Western Ghats of India

Climate change and human activity have significantly contributed to the decline of biodiversity worldwide. Orchids, in particular, are sensitive to disturbances and may respond rapidly to the impacts of climate change than many other plant species. Due to their complex biology and the pressures placed on their habitats, orchids are considered a highly vulnerable group of plants. The lateritic plateaus of northern Western Ghats support a variety of life forms and are quite fragile in nature. The slightest pressure on the habitat affects all the flora and fauna thriving in these microhabitats. Habenaria suaveolens is one of the endemic orchids that can be found growing in these habitats only. In the present study, we examine the effect of climate change on the distribution of threatened H. suaveolens utilizing ecological niche modeling for present and future climatic scenarios (SSP 2-4.5 & SSP 5-8.5) to identify key environmental determinants and population parameters. A total of 25 occurrence records were used to study the SDM model using the MIROC6 global climatic model. The result revealed that only 19.50% (7921 km2) is highly suitable for the species in the current period. The highly suitable area reduces from 57.99% (SSP245) to 74.12% (SSP585) in 2090. Moreover, the total suitable habitat gets confined to less than 1000 km2 in future climatic conditions. The major environmental variable that predicts the distribution of the species are Bio17 (Precipitation of driest quarter), Bio1 (Annual Mean Temperature), Bio2 (Mean Diurnal Range), and aspect. Recently, the species is becoming less in population due to man-made activities like quarrying, tourism, grazing, trampling, etc., in and around the lateritic plateaus, leading to disturbances in the habitat. This study has provided a baseline data about the contiguous distribution of the species and its potentially suitable habitats in the future for conservationists to take precautionary steps for the protection of the species. Hence, a strategic plan can be compiled based on this to conserve these highly habitat specific plants.