漩门湾围垦区外滩涂不同生境大型底栖动物功能群及其变化

为研究围垦后滩涂湿地不同生境中大型底栖动物的功能群及其变化,于2010年10月至2012年7月在漩门湾围垦区外滩涂湿地3种生境进行了8个季度的大型底栖动物采样调查。3种生境各选2条与海岸线垂直的带状断面,各断面布设5个样点,每个样点均选取4个样方,用定量采样器采集泥样。两周年定量采集共获得大型底栖动物49种,隶属5门5纲29科。依据食性类型将底栖动物划分为浮游生物食者(Planktophagous group,Pl)、植食者(Phytophagous group,Ph)、肉食者(Carnivorous group,C)、杂食者(Omnivorous group,O)和碎屑食者(Detritivorous group,D)5个功能群。结果表明,互花米草草滩(HH)各功能群的物种数分别为6、10、13、6、5种,共计40种;自然光滩(GT)分别为4、8、12、11、6种,共计41种;红树林泥滩(HS)分别为5、8、12、7、4种,共计36种。两周年3种生境内Pl和Ph始终为主导功能群,其密度和生物量均较高,且平均密度和平均生物量均是PlPh。对两周年各生境功能群的多样性指数(Margalef丰富度指数、Shannon-Wiener多样性指数以及Pielou均匀度指数)进行无重复双因素方差分析表明:两周年中3种多样性指数在生境间均无显著性差异;两周年中S在功能群间均有极显著差异,第1周年H'、J在功能群间均无显著性差异,第2周年H'有极显著差异,J有显著差异。

Macrobenthic functional groups in different habitats in the reclaimed wetland Xuanmen Bay

Functional groups of macrobenthos are vital for the assessment of changes in the ecological functions of wetlands. This is especially true for reclaimed wetlands. To better understand the functional groups of macrobenthos in reclaimed wetlands, we performed seasonal surveys of three different habitats in the reclaimed wetland Xuanmen Bay from October 2010 to July 2012. Forty-nine macrobenthic species were identified, belonging to 29 families, 5 classes, and 5 phyla. Macrobenthos were classified into five functional groups according to food preference, including the planktophagous(Pl), phytophagous(Ph), camivorous(C), omnivorous (O) and detritivorous(D). The number of species collected was 6, 10, 13, 6 and 5 in the Spartina alterniflora tidal flat (HH); 4, 8, 12, 11 and 6 in the natural tidal flat(GT); and 5, 8, 12, 7 and 4 in the mangrove forests tidal flat (HS), respectively. The Pl and Ph exhibited higher density and biomass, and therefore occupied the dominant position among the five functional groups in all three habitats in both years. In addition, the average value for density and biomass of the Pl was consistently higher than that of the Ph. Density, biomass and the biodiversity indices (Margalef S, Shannon-Wiener H'' and Pielou J) for each functional group in the three habitats changed across years. Two-way ANOVAs were used to analyze the effect of habitats and functional groups on the biodiversity indices. The results indicated no significant difference among habitats(P > 0.05); S was significantly different among different functional groups in both years(P < 0.01); H''(P > 0.05) and J (P > 0.05) indicated no significant difference among different functional groups during the first year; and H''(P < 0.01) and J (P < 0.05) were significantly different among different functional groups during the second year.