A comprehensive new study has revealed that climate change and habitat fragmentation are placing 127 threatened plant species across South Asia at severe risk, with more than 80% of species projected to lose suitable habitats under the highest emission scenario by 2070.

The research, published in Geography and Sustainability, provides a multi-species assessment of its kind for the region, covering approximately 9.1 million square kilometers across India, Nepal, Bhutan, Myanmar, Afghanistan, Pakistan, and parts of China. The study was completed by researchers from Xishuangbanna Tropical Botanical Garden (XTBG)of the Chinese Academy of Sciences, in collaboration with institutions across Asia, Australia, and Europe.

The researchers assessed 127 threatened plant species across a transboundary region in Southwest Asia, using 8,503 species occurrence records and 24 environmental variables. They modeled habitat suitability, fragmentation dynamics, and conservation gaps under current conditions and future climate scenarios (2050 and 2070), including both moderate and high-emission pathways.

They found that only 6.05% of the region is suitable for these plants, primarily concentrated in the western, central, and eastern Himalayas and the Western Ghats of western India, characterized by low patch density but high connectivity.

By 2050–2070, highly suitable habitats will significantly decline, with only 9.39%-14.33% overlapping with existing protected areas; 44.40%-83.3% of species may lose suitable habitats, fragmentation increases to 36.39%, and connectivity decreases.

Among 24 environmental variables analyzed, five emerged as the most influential predictors of habitat suitability: mean annual temperature, temperature seasonality, mean diurnal temperature range, precipitation of the driest quarter, and net primary productivity. Temperature seasonality was identified as the dominant factor, reflecting the strong reliance of many plant species on predictable thermal cycles that regulate flowering, seed production, and dispersal.

The study highlights the need to expand and connect existing protected areas while implementing climate-adapted conservation strategies to address rapid environmental changes. Specific measures include establishing climate refugia, optimizing conservation network layouts, and strengthening transboundary collaborative management.