Dynamics of Litter Production and Decomposition: A Case Study from A Tropical Coastal Lagoon, Malaysia (Early View)

Abstract

Litter production and decomposition are the controlling factors in carbon dynamics and energy fluxes within mangrove ecosystems. The rate of decomposition is regulated by biotic and abiotic factors in many mangrove ecosystems worldwide. The limited information on litter production in a tropical lagoon and faunal effect in decomposition process makes it challenging to understand the impact on ecosystem functioning. Thus, study was examined: i) Monthly rate of litter production and ii) the decay pattern of leaf litters of two mangrove species, Bruguiera gymnorrhiza and Rhizophora mucronata at different positions i.e., forest floor, hanging position, and burial position, using 0.50 mm mesh litter bags.  To estimate the litter production one seasonal year was observed and 120 days research trial was carried out to examine the decay pattern of leaf litters in a tropical lagoon mangrove ecosystem. The total annual litter fall production was recorded ~1325 g/m², and leaves were the major contributor (59%) to litter production throughout the year. In litter decomposition, both the decay rate and the percentage of wet losses were high (50%) during the first ~30 days of the study. Due to the different physicochemical characteristics of the leaf (i.e., toughness, lignin content, C:N ratio, and other phenolic) of two mangrove species a significant changes (F = 4.55, p < 0.05) were found in the decay pattern. There was also a significant difference (F = 14.19, p < 0.001) in the decay constant at different positions during the experimental period, and the pattern of loss was highest on the forest floor, followed by hanging and burial positions for both species. Findings suggest that employing various positions in decomposition experiments can enhance the overall understanding of ecological impacts on ecosystem functioning and dynamics in tropical mangrove ecosystems.