Vascular Plant Diversity in a Changing World: Global Centres and Biome-Specific Patterns

Abstract

We summarize research on the global centres and gradients of vascular plant diversity. Most centres of plant species richness are located in geodiverse areas of the humid tropics and sub-tropics, especially in forest biomes. When focussing on the rarity of the flora, islands play an outstanding role. Endemism-scaled richness of oceanic island floras (endemism richness) exceeds those of mainland regions by several-fold. In contrast to the situation for most other groups of organisms, biodiversity patterns are relatively well understood for plants and vertebrates. However, plant diversity of some of the most important centres is still insufficiently documented – an important impediment for its conservation and sustainable use. Though habitat conversion and overexploitation have yet the most severe impact on plant diversity, future climate change is adding an additional threat. This will likely affect plant diversity, especially in low-latitude countries, which contributed least to the human-induced greenhouse gas emissions.