Large‐scale energetic and landscape factors of vegetation diversity

We show that at large scale the species number of vascular plants can be predicted to a major extent by climatically determined latent heat for evaporation and geometrical structure of landscape, described as an altitudinal difference. Application of the energy‐equivalence rule across plant communities for transpiration per area unit, and use of fractal theory for the description of habitat occupation by vegetation results in a physically based species–energy relationship. Application of averaged global constants in the relationship results in a species–area equation with known parameters. Despite its simple form, this species–energy relationship generally reproduces global patterns of vegetation diversity at two scales – 10 000 and 100 000 km 2 – and is applicable for different regions across scales from 100 to million km 2 . The proposed theory produces more robust results compared with the correlated‐based approaches, which link plant diversity patterns with climate variables, and allows the inclusion of an evolutionary component. The final climate‐richness equation for vascular plants has a simple and consistent analytical form and requires easily measurable variables.