Search

Ecosystem carbon stocks were compared in three island mangrove forests, subjected to different anthropogenic stresses, close to Port Klang in Selangor State on the west coast of Peninsular Malaysia. Carbon stocks in living biomass, litter, deadwood and soil were quantified, and the carbon isotopic signature in mangrove soils was also measured, to estimate their carbon source. We hypothesize that carbon stock would be more readily available in undisturbed mangroves. The results indicated that, in general, soil organic carbon pool comprised the majority of the ecosystem carbon stock, while dead organic matter made a negligible contribution. The highest ecosystem carbon stock was measured in the permanent undisturbed mangrove reserve on Pulau Klang. Carbon isotope data revealed that disturbed mangroves in Pulau Ketam had a more enriched δ13C signature of soil samples compared to the other two sites. The soil organic carbon in Pulau Ketam was mostly derived from mangrove materials (92.8%). The results suggested that the organic carbon accumulated in the soils was not only regulated by the burial of mangrove-derived organic carbon, but also the site conditions. • Ecosystem carbon stock in mangrove environment can be influenced by its land use status. • Soil organic carbon in undisturbed mangrove forest can contribute to the majority of the ecosystem carbon stock, regardless of the vegetation stands. • Isotope data revealed that the mangrove leaf and suspended particulate organic matter in the sea water are the sources of soil organic matter. [ABSTRACT FROM AUTHOR]

In the Matang Mangrove Forest Reserve (MMFR), the role of microzooplankton (20–200 μm) grazing on phytoplankton as a channel for carbon transfer to higher trophic levels was investigated. Our results showed that primary production was higher during the southwest monsoon (SWM) (1905 ± 1478 μgCl−1d−1) than in the northeast monsoon (NEM) (708 ± 474 μgCl−1d−1). Microzooplankton grazing was tightly coupled to primary production in both SWM and NEM, accounting for 97% and 68% of primary production, respectively. Both primary production (activation energy: 1.29 ± 0.54 eV) and microzooplankton grazing (2.05 ± 0.63 eV) showed temperature dependency, and revealed a shift towards heterotrophy with seawater warming, specifically at temperatures above 32 °C. As a conclusion, the microbial food web in MMFR is characterised by high primary production that was efficiently grazed by microzooplankton. • Relative to other tropical mangrove forests, primary production in the mangrove estuary of Matang was high. • Microzooplankton grazing was tightly coupled to primary production. • There were monsoonal differences in the classical food chain but not in the microbial loop. [ABSTRACT FROM AUTHOR]