Data synthesis for biodiversity science: a database on plant diversity of the Indian Himalayan Region

In an era of global environmental change, empirical synthesis of biodiversity data across geographic scales and taxonomic groups is urgently required. Recently, with an upsurge in data synthesis, substantial progress has been made in making massive biodiversity data available on a global scale. However, most of these databases lack sufficient geographic coverage, particularly from biodiversity hotspot regions of developing countries. Here, we present a comprehensive and curated plant database of the Indian Himalayan Region (IHR) – home to two global biodiversity hotspots. The database, currently comprising 11,743 native plant species, has been collated from an extensive quantitative synthesis of 324 floristic studies published between 1872 and 2022. Based on this database, we investigate the patterns of species richness, distribution, life-history traits, endemic and threat status of the native flora of the IHR, and the results revealed that these patterns vary considerably among the 12 states of the IHR. Sikkim harbours the highest number of plant species (5090), followed by Arunachal Pradesh (4907). We found a total of 1123 species (ca. 10%) endemic to India and 157 threatened species occurring in the IHR. The life-history traits (growth form and lifespan) were unequally represented between the Himalaya and the Indo-Burma hotspots. We found herbs as the dominant growth form across the IHR. Also, maximum species similarity was found between Jammu and Kashmir and Himachal Pradesh (Cs = 0.66), and minimum between the former and Meghalaya (Cs = 0.13). Overall, our study represents a significant step forward in filling the knowledge gaps from the global biodiversity hotspots in India, with immense management and policy implications.