Phytogeographic insularity through heterogeneity in landforms is the key for evolution and functional distinctiveness of land plants on the earth. Classically, biogeography as a discipline started about 200 years ago primarily with the study of taxon rarity by naturalists through the concepts of biological insularity in oceanic islands. A little later in time, scientists started drawing analogies of rich biodiversity in mountains with oceanic islands; they called these mountain systems “sky islands'' or “edaphic islands” or simply “montane islands” as naturalists discovered a large part of this taxon rarity, technically called endemism, on these mountains. The question is what physical landscape in a mountain system is congenial for a rich endemic flora to flourish? In other words, what are the factors that govern insular biogeography of mountain systems? Invariably, unfortunately and misleadingly, these islands are referred to either as mountaintops or else there is no clear definition of what makes these islands. To understand the factors we need to identify the features of geobotanic similarity/dissimilarity, and homogeneity/heterogeneity. In this study, we compare 15 sites of rich plant biodiversity, identified by us through the use of literature, across the Himalaya, and we have tried to gain insights about the geobotanic similarity and related features, and arrived at emergent relationships between these sites.
Spatial distribution of species hotspots in the Himalaya – identifying relationships between the salient geobotanic features