Ecological roles of commercial mangrove plantation forests for benthic macroinvertebrate communities in Thailand

Abstract

Mangrove plantation for renewable energy production has an important economic value for Thai inhabitants. Planted mangroves may also serve as valuable areas for biodiversity. We aimed to investigate benthic community structure and estuarine environment in mangrove plantation sites (young, intermediate, mature sites and a semi natural mangrove forest) in Samut Songkram province. The mangrove plantation is a monoculture of Rhizophora apiculata compared with a semi natural mangrove forest where 5 species of trees were recorded. Values of mangrove height and diameter at breast height (DBH) increased with the age of the mangrove plantation forests. Overall, the parameters reflected good water quality conditions (temperature 30.75-32 ºC; pH 6.69-7.73; salinity 16.33-21.66 ppt; DO 3.45-4.57 mg/l). Nutrient concentrations and BOD were rather low indicating less impact from nutrient sources. In term of biodiversity, phytoplankton and zooplankton appeared to be greater in younger mangrove plantation sites. Intertidal benthic macroinvertebrate communities tended to increase with the age of the plantation site and invertebrate assemblages have developed through time. Hence, it could be stated that mangrove plantation used as charcoal production not only generates income for the local people but also plays an important role in estuarine ecosystems as the crucial habitat for benthic macroinvertebrate species.