Estimation of Variation in Productivity of South Asian Terrestrial Ecosystem and Carbon Balance Using LPJ- GUESS DGVM Model

Abstract

Human induced change in climate has already started affecting the ways ecosystems function and interact with each other. The major impact, and which in turn also becomes the driving factor in climate change is disruption of carbon cycle. Apart from other consequences, one of the major impacts disruption of carbon cycle is going to have is on the growth of vegetation. As with the changes in atmospheric CO2 concentrations, Net Primary Production (NPP) of plants and Net Environmental Exchange (NEE) also vary. South Asia like many other parts of the world is also undergoing climate change and is facing changes in land cover and land use. As, population in South Asia is growing at an extremely high rate, the resources required to cater the needs of growing population are also increasing. Consequently, the terrestrial ecosystems and their interaction with atmosphere is also undergoing a change. To measure and estimate these changes, several Dynamic Global Vegetation Model (DGVM) are used. Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS) is also one of them. LPJ-GUESS is a process-based framework which models the dynamics and structure of the ecosystem. It is comprised of several sub-models, where each sub-model includes processing of associated ecological processes. Input data required for LPJ-GUESS is consisted of climate parameters (Temperature, Precipitation, Solar radiation) and concentration of carbon dioxide in atmosphere. This study intends to estimate and analyze the changes that vegetation growth in South Asia is experiencing and will continue to experience as a consequence of changing climate, by using LPJ-GUESS model. This study can be of great assistance to formulate climate mitigation and adaptation policies for South Asia.