Tracing the carbon flow in tropical watershed using stable isotope technique

Research on catchment area have traditionally involved concentration and flux measurement to better understand weathering, transport and cycling of materials from land to sea. Potentially, modification of terrestrial environment can alter the carbon flow in a catchment. This research is to characterize dissolved inorganic carbon (DIC) in Sungai Kurau and Tasik Bukit Merah. A progressive depletion of (δ¹³C–DIC: -14.20 ± 0.47‰) towards downstream (δ¹³C–DIC: -24.44 ± 0.59‰) is observed. The trend indicates photosynthesis activity at the upper stream system where microbial respiration process is observed to occur at the Tasik Bukit Merah located at downstream area. The dynamic of carbon pathway is highly affected by allochthonous input and autochthonous process in the catchment system. Land use activities within the catchment can disturb the balance between biological and geological processes which control the carbon pool in Kurau catchment