Variation in diatom community structures:Comparison between sampling procedures and spatial gradients

Abstract

The distribution of diatom is closely related to the habitat characteristics. But some anthropogenic factors,such as sampling method,sample preparation and species identification may affect the result of analyzing community structure. It is necessary to ensure no misleading judgments that would be generated by these factors in the diatom community ecology study because such misleading judgments may affect the evaluation of water quality. This paper was to quantify the amount of variability in community structure of benthic diatom,which related to sampling method and sample preparation. The results showed that the variability in community structure was minimal among sub-samples( repeated microscope slides of the same sample) and samples( repeated sampling at the same site),1. 26% and 1. 97%,respectively. Differences in community structure were 3. 38% at two sites located in the same river. Amount of dissimilarity in community structure across the streams was up to 42. 03%. Multivariate analysis suggested that field sampling and sample preparation did not contribute to a large amount of variation in our analysis of diatom community structure that related to habitat conditions across sites. Therefore,in the study of diatoms community in river areas,emphasis should be put on the effects of environments rather than the factors about sampling methods.