Assessment of water ecological health in small watersheds in the mountainous areas of Beijing based on the biological integrity of macrozoobenthos
The health of aquatic ecosystems in Beijing's mountainous small watersheds plays a crucial role in ensuring the ecological security of the Beijing.To systematically evaluate the health of the aquatic ecosystems in these watersheds,126 small watersheds in the mountainous areas of Beijing were studied,focusing on macrozoobenthos as the subject of research.Sampling points were established at 378 locations,resulting in the collection of 163 species of macrozoobenthos,including 136 species of arthropods,17 species of mollusks,9 species of annelids,and 1 species of flatworms.Based on the tolerance value grading standards,sensitive macrozoobenthos groups accounted for 16.56%,and pollution-tolerant macrozoobenthic groups accounted for 11.04%.In terms of the frequency of macrozoobenthic groups,12 species had a frequency greater than 20%,with the top three being the Baetidae,Caridina,and Neocaridina,with frequencies of 0.7619,0.5079,and 0.4444,respectively,all belonging to the moderately pollution-tolerant groups.Thirteen reference points were selected,and after testing the distribution range and analyzing correlations of 28 candidate indicators,a B-IBI evaluation system for the small watersheds in Beijing's mountainous areas was developed,including four core indicators:number of Plecoptera+Mollusca taxa(M6),relative abundance of EPT(M10),relative abundance of direct collectors(M20),and the Shannon-Wiener diversity index(M25).The ratio method was used,the 25%quantile of the reference point B-IBI index value was set as the standard for evaluating the health of aquatic ecosystems in Beijing's mountainous small watersheds.The evaluation results showed that 35 watersheds were in a healthy state,55 in a sub-healthy state,32 at a general level,and 4 at a poor level.Overall,the health of the aquatic ecosystems in Beijing's mountainous small watersheds is relatively good,with localized degradation trends being observed.
macrozoobenthosindex of biological integritysmall watershedswater ecological health assessment
万方数据
维普
