中文摘要：

沼泽地在生态系统起一个很重要的作用。Qixinghe 沼泽地是在东北中国的一个自然保护区区域。在这份报纸，硅藻社区和环境质量在 Qixinghe 沼泽地在八个地点被调查。这研究是在沼泽地在与环境变量的关系检验硅藻种类模式，并且把硅藻用作指示物在沼泽地和沼泽地分类浇质量。硅藻在 2002 和 2004 在夏天和秋天被取样，在哪个期间 180 taxa 被识别。在 pH，温度，生物化学的氧需求(BOD ) ，和化学的氧需求(货到付款) 的环境变化被测量。季节的作文和许多硅藻在学习时期期间极大地变化了。在硅藻和化学的水质量之间的关系统计上被估计。有前面的选择和蒙特卡罗排列测试的正规通讯分析(CCA ) 表明所有浇在学习时期期间改变的环境变量(P < 0.05 ) 。在所有参数之中，在在这些地点之中的 BOD 的变化根据 CCA 是种类作文的一个很重要的决定因素，并且 BOD 从 2002 ～ 2004 减少了。我们的结果建议因为提高的环境保护，水质量与更少的人的骚乱在三年的时期期间改善了。我们断定硅藻能被用来在这块沼泽地显示水质量和产地条件。

英文摘要：

Wetlands play a very important role in ecosystems. Qixinghe Wetland is a nature reserve area in northeastern China. In this paper, diatom communities and environmental qualities were investigated at eight sites in Qixinghe Wetland. This study was to examine diatom species patterns in relation to environmental variables in wetlands, and to use diatoms as indicators to water quality in wetlands and wetland classification. Diatoms were sampled in summers and autumns in 2002 and 2004, during which 180 taxa were identified. Environmental variations in pH, temperature, biochemical oxygen demand （BOD）, and chemical oxygen demand （COD） were measured. The seasonal composition and abundance of diatoms changed greatly during the study period. The relationship between diatoms and chemical water quality was estimated statistically. Canonical correspondence analysis （CCA） with forward selection and Monte Carlo permutation tests revealed that all water environmental variables changed during the study period （P〈0.05）. Among all the parameters, variation in BOD among the sites was a very important determinant of species composition according to the CCA, and BOD decreased from 2002 to 2004. Our results suggest that the water quality had improved during the three-year period because of enhanced environmental protection with less human disturbance. We conclude that diatoms can be used to indicate water quality and habitat conditions in this wetland.