不同基质上着生生物群落生态学特性比较研究

为了寻找最佳采样基质和方法，研究使用各种不同自然和人工基质对天然水体中的着生生物群落进行了采样。自然基质选取菹草、光壳钉螺和沿岸石块。人工基质采样装置由载玻片和染色架构成．使用时悬挂于河水之中。对各基质上的着生生物现存量、藻类细胞密度、着生藻类叶绿素a和着生生物干重等生态学指标进行了分析和比较．并简要分析了造成差异的原因。分析结果表明，各基质上着生藻类在种类组成上基本相似，以硅藻门、绿藻门为主。优势藻种为舟形藻属短小舟形藻、异极藻属缢缩异极藻和脆杆藻属克洛脆杆藻。不同基质上着生藻类的组成与藻类习性和细胞构造有关，与基质无关。但是不同基质也造成藻种间多样性的差异．这可能与基质表面粗糙程度、水流方向有关。附石藻类表征水体污染效果最好，所以建议采样时选取形状规则的石块为基质．最能反映着生生物群落的真实情况。

Ecological Characteristics of Periphyton Communities on Different Kinds of Substrates and Comparison

By using a variety of natural and artificial substrates, periphyton communities in natural rivers were collected and analyzed to determine the best kind of substratum and the sampling method. Potamogeton crispus, Oncomelania Gredler and coastal rocks were selected as the natural substrates. Artificial substrate sampling devices were composed of glass slides and staining rack, which were immerged into the river while used. Ecological indicators were analyzed and compared on each kind of substrate, including the standing stock, algae cell density, chlorophyll-a and biomass dry weight. The analytical results show that the species composition of the algae is similar and the majorities are Bacillariophyta and Chlorophyta. The dominant species are N.exigua, Gomphonema constrictum and F.crotomensis. The species compositions are relative to the habits and structures of the algae but it has nothing to do with the substratum. However, different substrates have caused the differences of algae biodiversity, which may be related to the roughness of the substrate surface and the direction of flows. The characteristic of epilithic algae can best indicate the pollution of water. Thus, the conclusion suggests coastal rocks of regular shapes be used or collected to sample the periphyton community because they can best reflect the circumstances of the periphyton community.