Photosynthetic characteristics and leaf litter production of mangrove forests in Trang, southern Thailand

Abstract

The aim of this study was to investigate the photosynthetic performance and litter production of planted (PLA) and natural (NAT) mangroves in Trang, southern Thailand. Relative chlorophyll content and other photosynthetic parameters, such as photosynthetic efficiency of Photosystem II (Phi2), yield of non-regulatory energy dissipation (PhiNO), yield of non-photochemical quenching (PhiNPQ) and quenching due to non-photochemical dissipation of absorbed light energy (NPQt), and litter fall production were determined and compared between two mangrove stands. Measurements of photosynthetic parameters were made using PhotosynQ to assess the health of the community structure in both stands. The assumption of this study, namely that there would be no significant difference in any photosynthetic parameter measured between the two stands, was confirmed using t-test with unequal variances confirmed (P>0.05 for all). Changes occurred quarterly and in sites with different species. In terms of litter production, significant differences were found according to stand (P<0.001), season (P < 0.05) and site (Sikao, F3,129=4.357, P<0.01; Kantang, F3,190=3.243, P<0.01). PLA stands demonstrated similar photosynthetic characteristics to NAT stands. This study established the effects of land use changes on PLA mangroves (planted in an abandoned shrimp pond). The overall significance of the study is in highlighting the positive outcomes of mangrove restoration, particularly in degraded mangrove stands due to land use change.