排序方式： 共有46条查询结果，搜索用时 31 毫秒
21.
开展湟水河干支流大型底栖动物调查研究,为湟水河水生态保护修复提供参考依据。于2020年9月对湟水河流域25个样点进行了样品采集和调查,了解湟水河全流域大型底栖动物群落结构并识别影响其空间分布的关键环境因子。共采集并鉴定出大型底栖动物109（属）种;依据大型底栖动物群落结构相似性,湟水河25个样点在空间上可以分为3组：第1组样点主要分布在中上游支流,该组指示物种为朝大蚊属1种（Antocha sp.）;第2组样点分布比较广泛,中上游干、支流均有,该组的指示物种为四节蜉属1种（Baetis sp.）;第3组样点主要分布在中下游干流,该组指示物种为瑞士水丝蚓（Limnodrilus helveticusi）。大型底栖动物的物种丰度、香农威纳指数、Margalef丰富度指数、四节蜉属1种和瑞士水丝蚓的相对丰度在上下游和干支流之间的空间差异性较大。冗余分析（RDA）结果表明栖息地质量、电导率、亚硝态氮、总磷、浊度和水深是影响湟水河大型底栖动物的关键环境因子。湟水河水生态保护应当更多地关注次生盐化和营养盐污染,加强治理上游过度放牧造成的水土流失和农业面源污染。 相似文献
22.
选择大型底栖生物作为白洋淀湿地健康指示生物,将B-IBI评价方法应用到白洋淀湿地健康评价中,为白洋淀湿地管理和调控提供科学依据。根据9个受损点、6个参照点的大型底栖动物样点数据,对白洋淀湿地23个生物参数的分布范围、判别能力和相关性进行分析,确定B-IBI指数由总分类单元数、优势分类单元个体百分比和摇蚊个体百分比构成。采用比值法计算各生物参数指数值,并将各参数值加和得到B-IBI指数值。根据参照点B-IBI值的25%分位数值确定健康等级标准：〉2.302为健康,1.590~2.302为亚健康,0.879~1.589为不健康,〈0.879为病态。评价结果表明：淀区9个样点中有1个样点处于健康状态,4个样点处于亚健康状态,4个样点处于不健康状态,白洋淀湿地大部分水域健康均受到一定损害。B-IBI与透明度呈显著正相关,与TN、TP和叶绿素a呈显著负相关。 相似文献
23.
Abstract – We examined the effects of snorkeling, a commonly used fish observation technique, on the distribution and abundance of benthic macroinvertebrates at both the reach (i.e., 10 m) and patch scale (i.e.,< 1 m) within a southern Appalachian stream (North Carolina, USA). At the reach scale, we quantified increases in macroinvertebrate drift rates associated with snorkeling and used these values to calculate the percentage of the macrobenthos that drifted out of snorkeled reaches. We also used a simple decay model of macroinvertebrate drift to quantify patch scale effects of snorkeling. The model incorporated size specific macroinvertebrate settling rates to estimate the total number of benthic macroinvertebrates that entered the drift in response to snorkeling disturbance. We found that snorkeling consistently produced significant increases in the number of drifting macroinvertebrates. Nevertheless, these increases comprised a very small percentage (<1%) of the total number of organisms in the benthos, suggesting that snorkeling probably did not strongly affect macroinvertebrate assemblages at either the reach or patch scale. However, our analyses also indicated that snorkeling had a disproportionate effect on the drift of small ephemeropterans (4–5% entered the drift in response to snorkeling) relative to other macroinvertebrate taxa. Consequently, the microdistribution of early instar mayflies may have been altered within snorkeled reaches. We conclude that snorkeling related disturbance to the benthos should have a minimal effect on the behavior and distribution of most stream fishes at either the reach or patch scale. However, because snorkeling had a substantial effect on the drift of small mayflies, snorkeling may influence the behavior of fishes that depend on early instar mayflies as a primary food resource. Note 相似文献
24.
底栖动物生物指数水质评价进展及在中国的应用前景 总被引：8，自引：0，他引：8
介绍了基于底柄动物的3类广泛应用的水质生物评价参数:Saprobic指数、BI指数、群落多样性指数,并结合它们在水质和水资源管理中的应用现状分析了各指数的优缺点.Saprobic指数和BI指数已是欧盟成员国及美国等国重要的水质生物评价指数,中国的水质生物监测技术规范中尚缺乏类似的生物指数.分析了中国开展BI指数水质生物评价研究的现状,探讨了中国建立BI指数评价标准与规范的研究基础、不足、应用前景和今后的研究建议.同时指出,目前的研究重点是底柄动物耐污值计算和BI指数水质基准. 相似文献
25.
渔洞水库大型无脊椎动物群落结构及其与环境关系的初步调查 总被引：1，自引：0，他引：1
于2009年12月、2010年3月、6月和9月共4次对渔洞水库的大型无脊椎动物进行了调查,共采集到动物19个分类单元,隶属于3门3纲5科16属。其中,寡毛类、水生昆虫及软体动物等主要类群分别记录6种(占总物种数的31.6%)、12种(63.2%)和1种(5.3%)。大型无脊椎动物密度优势类群主要为霍甫水丝蚓(Limnodrilus hoffmeisteri Claparède)、前突摇蚊(Procladius sp.)和长跗摇蚊(Tanytarsus sp.)。渔洞水库的大型无脊椎动物在冬春季的现存量较夏秋季高,库湾的多样性高于主体库区。多余度分析(RDA)显示,水深和溶氧是影响渔洞水库无脊椎动物群落分布的关键环境因子。4次调查中寡毛类密度均未超过1 000 ind./m2,水质属轻度污染。 相似文献
26.
2013年4月,根据沙颍河干流闸坝分布设置21个采样站位对处于生态恢复期的沙颍河干流底栖动物进行了现场调查。共采集到底栖动物3门6纲10目25科38种,其中,水生昆虫20种、甲壳动物3种、寡毛类2种、软体动物11种、其他类群2种。沙颍河干流底栖动物平均密度242.40个/m2,平均生物量291.33 g/m2;软体动物占绝对优势,在现存量中占总个体数的64.74%,且在绝大部分站位占据优势地位;常见种为梨形环棱螺、环足摇蚊属一种、圆顶珠蚌和大沼螺。经生物多样性分析,Shannon-Wiener指数平均为1.20,Margalef指数平均为1.56,Pielou均匀度指数平均为0.52。将21个站位的底栖动物进行聚类分析,可分为8大组群,NMDS分析显示各组群分离较为明显,表明底栖动物群落结构的空间异质性较高;SIMPER分析表明空间变异度取决于梨形环棱螺、环足摇蚊、长臂虾科1种、水丝蚓属1种、大沼螺和摇蚊的种群动态变化。从底栖动物群落结构组成来看,周口闸以上河段水质要明显好于周口闸以下,周口闸以下河段水质状态也与污染严重时期相比有较大改善。 相似文献
27.
于2016年8月(丰水期)、11月(平水期)和2017年2月(枯水期)对藻渡河流域大型底栖动物群落结构和功能摄食类群进行了调查研究。结果显示:共采集大型底栖动物34种(属),隶属4门14目27科,扁蜉(Heptagenia sp.)、二尾蜉(siph1onurus sp.)、二翼蜉(Cloeon dipterum)、泉膀胱螺(Physa fontinalis)和狭萝卜螺(Radix lagotis)为该地区的优势类群。不同季节Shannon-Wiener多样性指数、Pielou丰富度指数和Marglef均匀度差异显著,且枯水期>平水期>丰水期。CCA分析显示丰水期水温、透明度和海拔等是影响藻渡河大型底栖动物空间分布的主要因素。该流域大型底栖动物功能摄食群落以捕食者和刮食者为其优势功能类群,其次是撕食者、收集者和滤食者。 相似文献
28.
29.
- 1. The Water Framework Directive (WFD) requires member states to establish ‘type‐specific biological reference conditions’ for the assessment of surface waters and describes a method for establishing such biological targets. The methodology described in the Directive is based on geographic and physical characteristics and similar to the ‘multimetric’ approach used widely in North America, but contrasts with the biological classification of the ‘multivariate’ approach which is commonly used in Europe.
- 2. An investigation was made of the relative efficiency of the multimetric and multivariate classification approaches in partitioning the observed biological variation of the macroinvertebrate communities of 22 minimally disturbed lakes in Northern Ireland. Furthermore, the accuracy of predictive models based on the two approaches was compared.
- 3. The WFD environmental typologies partitioned the observed biological variation poorly with a maximum ANOSIM R‐value of 0.216 compared with 0.609 for a multivariate biological site classification. The WFD System B approach partitioned more variation than the System A approach.
- 4. The use of a predictive model, based on any of the site classification approaches, resulted in more accurate faunal predictions than a null model. However, the biological model produced the most accurate predictions.
- 5. Canonical correspondence analysis showed that the environmental variables used in the biological classification model explained more variation (28%) than the best‐performing environmental classification model (24%). The most important variable was pH, followed by surface area and altitude. The variables used in all approaches explained more variation when used as continuous rather than categorized parameters.
- 6. The results of this work, the first such comparative study of predictive models in lakes, concur with similar studies in streams. It may be concluded that large‐scale environmental classifications are unreliable as a method for setting type‐specific reference targets for the ecological assessment of fresh waters.
30.
香格里拉岗曲河大型底栖动物群落和水质的快速生物评价 总被引：1，自引：0，他引：1
首次针对香格里拉保护区水生生态系统状况进行调查.河源到河口共设置16个采样河段,采集到的大型底栖动物共计9目39科(亚科)61种(属),划分为34个不同敏感类群(科或属),并给出不同种类所指示的水质状况.采用香农生物多样性指数(Shannon-Wiener Diversity Index)和MBI生物指标(Macroinvertebrate Biotic Index)对大型底栖无脊椎动物群落进行计算、评价和分类,对岗曲河的水质状况进行快速生物评价.研究表明:除了一些靠近矿山和村庄下游河段,香格里拉保护区水生生态系统生物种类组成丰富、水质状况良好,其调查数据和研究结果是进一步开展保护区水生生态系统研究的基础,也可作为同类型河流生态系统评价的参照. 相似文献