Assessment of land use impacts on net primary production of the central region in Thailand

The central region in Thailand has many land use types such as agricultural land, forest, urban and built-up land. The use of land for a long time or improving the area may cause damage to the ecosystem. So, assessing damage to the ecosystem productivity is necessary. Net primary production (NPP) in 2002, 2011, and 2019 in the central region was simulated using the Carnegie-Ames-Stanford Approach (CASA) model. The data employed in the model consist of the satellite data (normalized difference vegetation index (NDVI) and evapotranspiration from TERRA MODIS), solar radiation data from the Ministry of Energy of Thailand, and temperature data from the Thai Meteorological Department. Land use data in the central region was used to estimate the active light use efficiency by grouping selected representative plants.The past and present NPP were compared to assess the land use impacts on primary production. The increase of yearly NPP represents increasing productivity of the vegetation while the decrease of NPP represents that the productivity of the vegetation was decreasing over time. It was found that the development of land and change in land uses have influenced NPP decreasing trend in the central region of Thailand.