Sixteen different vegetation types of grassland and shrubland were selected to study the component and diversity of plant species of riparian plant communities along main channel in the Three-Gorges areas. Species ric...Sixteen different vegetation types of grassland and shrubland were selected to study the component and diversity of plant species of riparian plant communities along main channel in the Three-Gorges areas. Species richness (s), Simpson index (D), and Shannon-Weiner index (H) were used to study the biodiversity and the hierarchical classification was carried out by the methods of TWINSPAN and DCA ordination. The results showed that the components of flora were complex and dominated by the temperate type in the riparian plant communities. Species diversity was not different between the communities, but Shannon-Weiner indexes of different layers in some grassland were significantly different. TWINSPAN and DCA indicated that riparian plant communities distributed along the gradient of moisture.展开更多
Due to the importance of riparian zone in maintaining and protecting regional biodiversity, increasingly more ecologists paid their attentions to riparian zone and had been aware of the important effects of riparian z...Due to the importance of riparian zone in maintaining and protecting regional biodiversity, increasingly more ecologists paid their attentions to riparian zone and had been aware of the important effects of riparian zone in basic study and practical management. In this study, 42 sampling belts (10 m?00 m) parallel to the bank of Xiangxi River at different elevations in Shennongjia Area were selected to investigate the riparian vegetation and rare plants. 14 species of rare plants were found distributing in riparian zone, accounting for 42.4% of the total rare plant species in Shennongjia Area. The main distribution range of the 14 rare plant species was the evergreen and deciduous mixed broadleaved forest at elevation of 1200-1800 m, where, species diversity of plant community was the maximum at the moderate elevation. The analysis of TWINSPAN divided the 14 rare species into 3 groups against the elevation, namely low elevation species group, moderate elevation species group, and high elevation species group. The analysis of DCA ordination showed similar results to that of TWINSPAN. In the paper, the authors discussed the reasons forming the distribution pattern of rare plant species, and pointed out that the important function of riparian zone on rare plant species protection.展开更多
对受人类活动强烈影响、几乎不存在常规参照点的城市河流开展生态评价存在很多困难。研究基于2018年春季深圳市茅洲河水系调查数据,用水体理化指标聚类法确定参照组、受损组样点,从底栖动物多样性、群落结构、耐污能力、功能摄食类群等...对受人类活动强烈影响、几乎不存在常规参照点的城市河流开展生态评价存在很多困难。研究基于2018年春季深圳市茅洲河水系调查数据,用水体理化指标聚类法确定参照组、受损组样点,从底栖动物多样性、群落结构、耐污能力、功能摄食类群等角度确定候选参数,筛选出核心参数构建底栖生物完整性指数(Benthic index of biotic integrity,B-IBI)评价其生态状况。调查共采集到大型底栖动物62个分类单元,虽然茅洲河水环境质量整体较差,聚类分析仍然能将水质相对较好和较差的样点分成不同组。大型底栖动物以颤蚓和摇蚊等耐污种为主,大型底栖动物总分类单元数和集食者分类单元数对水环境变化较敏感。用这2个参数构建的B-IBI对各点的生态状况进行评价表明:12个位于干、支流上游或水库出水口附近的样点生态状况达到“好”等级;7个位于干流下游和汇入干流下游河段的支流样点为“差”,其他15个样点为“中”。NH_(3)^(-)N、TN、PO_(4)^(-)P和COD对B-IBI有显著负影响,DO浓度对B-IBI有显著正影响。建议参照“好”等级样点的生态状况确定茅洲河现阶段修复目标,并以水质提升作为当前首要修复任务。展开更多
基金This study was supported by the Chinese Academy of Sciences (A grant KZCX2-406) the National Natural Science Foundation of China (NSFC39970123) and Changbai Mountain Open Research Station.
文摘Sixteen different vegetation types of grassland and shrubland were selected to study the component and diversity of plant species of riparian plant communities along main channel in the Three-Gorges areas. Species richness (s), Simpson index (D), and Shannon-Weiner index (H) were used to study the biodiversity and the hierarchical classification was carried out by the methods of TWINSPAN and DCA ordination. The results showed that the components of flora were complex and dominated by the temperate type in the riparian plant communities. Species diversity was not different between the communities, but Shannon-Weiner indexes of different layers in some grassland were significantly different. TWINSPAN and DCA indicated that riparian plant communities distributed along the gradient of moisture.
基金This project was supported by National Natural Science Foundation of China (NSFC39970123) Changbai Mountain Open Research Station, Chinese Acedamy of Science.
文摘Due to the importance of riparian zone in maintaining and protecting regional biodiversity, increasingly more ecologists paid their attentions to riparian zone and had been aware of the important effects of riparian zone in basic study and practical management. In this study, 42 sampling belts (10 m?00 m) parallel to the bank of Xiangxi River at different elevations in Shennongjia Area were selected to investigate the riparian vegetation and rare plants. 14 species of rare plants were found distributing in riparian zone, accounting for 42.4% of the total rare plant species in Shennongjia Area. The main distribution range of the 14 rare plant species was the evergreen and deciduous mixed broadleaved forest at elevation of 1200-1800 m, where, species diversity of plant community was the maximum at the moderate elevation. The analysis of TWINSPAN divided the 14 rare species into 3 groups against the elevation, namely low elevation species group, moderate elevation species group, and high elevation species group. The analysis of DCA ordination showed similar results to that of TWINSPAN. In the paper, the authors discussed the reasons forming the distribution pattern of rare plant species, and pointed out that the important function of riparian zone on rare plant species protection.
文摘对受人类活动强烈影响、几乎不存在常规参照点的城市河流开展生态评价存在很多困难。研究基于2018年春季深圳市茅洲河水系调查数据,用水体理化指标聚类法确定参照组、受损组样点,从底栖动物多样性、群落结构、耐污能力、功能摄食类群等角度确定候选参数,筛选出核心参数构建底栖生物完整性指数(Benthic index of biotic integrity,B-IBI)评价其生态状况。调查共采集到大型底栖动物62个分类单元,虽然茅洲河水环境质量整体较差,聚类分析仍然能将水质相对较好和较差的样点分成不同组。大型底栖动物以颤蚓和摇蚊等耐污种为主,大型底栖动物总分类单元数和集食者分类单元数对水环境变化较敏感。用这2个参数构建的B-IBI对各点的生态状况进行评价表明:12个位于干、支流上游或水库出水口附近的样点生态状况达到“好”等级;7个位于干流下游和汇入干流下游河段的支流样点为“差”,其他15个样点为“中”。NH_(3)^(-)N、TN、PO_(4)^(-)P和COD对B-IBI有显著负影响,DO浓度对B-IBI有显著正影响。建议参照“好”等级样点的生态状况确定茅洲河现阶段修复目标,并以水质提升作为当前首要修复任务。
