Elevational patterns of seed plants and the driving mechanisms in the Himalaya.

The Himalaya is an important biodiversity hotspot on earth, which is of great significance to study the elevational gradients in plant diversity and its influencing factors for further revealing the formation of biodiversity and conservation. In this study, we measured the elevational range of 11886 seed plant species and different growth-forms (7918 herbaceous species, 2587 shrub species, and 1388 tree species) in the Himalaya. Using the optimal fitted regression models, we found that species richness and phylogenetic diversity of seed plants in the Himalaya mainly showed unimodal curves with the increases of elevation.