Numerical models of the terrestrial biosphere

Many efforts have been made to develop numerical models of biospheric processes in recent years. Generally speaking, three classes of global terrestrial biosphere models have emerged: (1) soil-vegetation-atmosphere transfer (SVAT) models, (2) terrestrial biogeochemistry models (TBMs), and (3) potential vegetation models (PVMs). In this manuscript, I summarize the main characteristics of these models and discuss the need for a more fully integrated biosphere model, which would combine aspects of (1), (2) and (3) in a single modelling framework.