Modelling of time-dependent biome shifts under global climate changes

The study of biosphere response to climate changes due to anthropogenic emission of greenhouse gases is a very important scientific and practical problem. The core of its solution -modelling and long-term forecast of global terrestrial vegetation changes -is considered in this paper. There are a few approaches To modelling long-term vegetation dynamics; their principles are discussed in brief. A model approach based on bioclimatic schemes has been chosen for further considerations. A model based on Holdridge's bioclimatic scheme was designed for simulation of time-dependent biome shifts. A procedure of time delays was designed to take into account inertia of vegetation response to climate change. It was based on expert estimates of biome replacements. Computer experiments have been designed to investigate the consequences of time-dependent climate changes for the vegetation of Russia. The results showed the importance of the temporal factor for long-term forecasts. The obtained assessments demonstrated complex non-linear dynamics of vegetation even under the simplest climatic scenario. Further prospects of suggested model were discussed.