Benthic communities and biodiversity in Thai mangrove swamps

1. 为了阐明红树林沼泽底栖动物的群落结构和生物多样性，1994 ~ 1996年在泰国Samut Songkhram省Klong Kone红树林沼泽进行了实地研究。我们设置了两条横断面线，从泥滩延伸到红树林的陆地边缘。森林内部沉积物的有机质含量高于泥滩，而间隙水的养分含量则呈现相反的趋势。通过定量和定性取样对底栖动物区系进行了研究。在外泥滩和移栽区，2年内密度呈上升趋势，以多毛纲Hypsicomus sp.和甲壳纲Apseudes sp.为主。红树林中腹足类、多毛类、尾足类、芝麻蟹类和厌食蜗牛类数量较多，3年来密度和物种丰富度较为稳定。从泥滩到林内，个体数量总体呈减少趋势。多样性指数则呈现相反的趋势。在移栽区，1994年种植的树苗生长到5 m左右的高度。随着红树林的生长，沉积物中的有机质增加。从1994年到1996年，物种数量也有所增加。为了研究藤壶的定植过程，我们在不同的环境下设置并监测了塑料测试杆。4 .低处分布的Balanus sp.和高处分布的Chthamalus sp.种群密度均高于林内。通过对原始森林和被砍伐森林底栖生物群落的比较，发现发达森林的存在对底栖生物群落的生物多样性保护具有重要意义。发表了我们项目三年的研究报告。

1. To elucidate the community structure and biodiversity of benthic animals in mangrove swamps, field studies were conducted at Klong Kone mangrove swamps in Samut Songkhram Province, Thailand from 1994 to 1996. We set 2 transect lines extending from mud flat to landward fringe of the mangrove forest. Organic matter in the sediments inside the forest were higher than those in the mud flat, but the nutrient concentrations in the interstitial water showed the opposite trend.2. We studied the benthic fauna by quantitative and qualitative samplings. In the outer mud flat and the transplanted area, the density increased during 2 years and Hypsicomus sp. (polychaete) and Apseudes sp. (tanaid crustacean) were dominant. In the mangrove forest, gastropods, polychaetes, ocypodid, sesarmid crabs and erobid snails were prominent, and the density and species richness were rather stable for 3 years. There was a general tendency for the number of individuals decrease from the mud flat to the inner part of the forest. However, diversity index showed the opposite trend.3. In the transplantation area, the saplings planted in 1994 grew to a height of about 5 m. Whit the growth of mangroves, the organic matter in the sediments increased. The number of species also increased from 1994 to 1996.4. For the studies of colonization processes of the barnacles, we set and monitored the plastic test poles at several different environments. The zonal distributions of Balanus sp. (occupying lower level) and Chthamalus sp. (upper) were observed, and population densities were higher at the mud flat than inside the forest.5. Comparison of the benthic communities between intact and deforested forests revealed that the existence of developed forests are important for the biodiversity conservation of benthic community. A research report of our project for 3 years is published.