海岸红树林地沙丘移动对林内大型底栖动物的影响

沙丘在广西北海大冠沙白骨壤红树林内的移动，破碎了原有的平滩，形成了埋没滩、过渡滩、侵蚀滩３种沙化滩涂生境。比较研究了不同滩涂生境间大型底栖动物群落的差异。结果表明：除藤壶外，研究地点共有大型底栖动物３１种。平滩跟其它滩涂生境间的动物群落相似度都小于０．５，表明沙丘移动使原有底栖动物群落异质化。沙化不仅使原有底栖动物群落的种类、密度和生物量分别下降了３５．１％，７４．６８％和８９．７６％，而且还降低

Influences of sand dune movement within the coastal mangrove stands on the macrobenthos in Situ.

In Daguansha,Beihai of Guangxi,the movement of sand dunes within Avicennia marina stands broke up the initial flat beach and formed buried,transited and eroded types of sand beach habitats.This study focused on the benthic differences among various habitats.It was indicated that there were totally 31 macrobenthic species in the study plot except barnacle.Heterogeneity occurred for the original through dune movement.The similarity values was less than 0.5 among flat and the other three habitats.The desertization not only decreased the species number,density and biomass from the original by 35 1%,74 68% and 89.76%,respectively,but also reduced the density of the initial dominant population,which was responsible for the augmentation of diversity values.The more serious the desertization was,the more unfavorable the surface living fauna became.However,with desertization,the proportion for the surface below living fauna in number of species,density and biomass was relatively increased.