PROJECTION OF SOIL CARBON CHANGES AND FOREST PRODUCTIVITY FOR 100 YEARS IN MALAYSIA USING DYNAMIC VEGETATION MODEL LUND-POTSDAM-JENA
Keywords:terrestrial carbon, climate change, land ecosystem, sustainable forest management
The gaseous exchange of carbon dioxide in the atmosphere will affect the rate of carbon uptake in the soils. When carbon dioxide increases, the productivity of soil organic carbon also increases. The study aimed to determine the soil carbon changes and forest productivity in Malaysia using climate data from five Global Climate Models on 0.5 × 0.5 grid resolution by implementing three scenarios from year 1990 to 2099. The Lund-Potsdam-Jena model calculated changes in net primary production and forest areas. The results showed
that soil carbon increased by 15% in Representative Concentration Pathway 8.5 (RCP8.5) but decreased by 17% in RCP8.5 C90. The simulated soil carbon change projection increased by an average of 2.5% by the year 2099 due to the increased carbon dioxide concentration. The soil carbon fell under the RCP8.5 C90 scenario by an average of -27.5%, which was caused by the increasing heterotrophic respiration due to an increase in temperature. Carbon dioxide concentration and temperature had a tendency to speed up decomposition.
Climate change will be a key driver of change in soil carbon over the 21st century as the forest ecosystems would respond to any future increase of carbon dioxide concentration by increasing forest productivity.