黄河三角洲潮间带动物多样性的研究   总被引：7，自引：0，他引：7  

蔡学军  田家怡 《海洋湖沼通报》2000,(4):45-52

以１９９６年黄河三角洲潮间带动物定性调查结果,分析了黄河三角洲潮间带动物物种多样性;以定量调查结果研究了潮间带动物多样度以及与均度、单纯度的关系。研究表明：该区共鉴出潮间带动物１９３种,隶属于１３个门１５个纲４０个目９４个科;潮间带动物多样度为０～１．７０,均度为１～１．００,单纯度为０．２２～１．００;多样度与均度呈正相关,与单纯度呈负相关关系。  相似文献   

Macrophyte diversity of lakes in the Pannon Ecoregion (Hungary)     

《Limnologica》2015

We examined the distribution of submerged and emergent macrophyte species and the entire macrophyte community within and between five lake types (highland reservoirs, alkali lakes, large shallow lakes, small to medium sized shallow lakes, marshes) in the Pannon Ecoregion, Hungary. The lowest submerged, emergent and total species richness was found in alkali lakes. The highest submerged macrophyte richness was in small to medium sized lakes, while the highest emergent macrophyte species richness was in reservoirs, small to medium sized lakes, and marshes. The values of within-lake type beta diversity were generally lower than the values of alpha diversity, especially for submerged macrophytes, indicating between site homogeneity in species composition within the lake types. Emergent macrophyte communities contributed the most to within and between lake type diversity and total (gamma) diversity. Canonical correspondence analyses showed that the main environmental variables which influenced the distribution of submerged macrophytes were conductivity, Secchi transparency and water nitrogen contents. For emergent macrophytes conductivity, lake width, altitude and water depth proved to be the most influential variables. Our results contribute to the knowledge of large-scale distribution of macrophytes in the Pannon Ecoregion and to the identification of conservation value of lakes using macrophytes. The results support the importance of small lakes and artificial lakes in the conservation of macrophyte diversity compared to large and natural lakes in the Pannon Ecoregion.  相似文献   

Impact of urbanization on the ecology of Mukuvisi River,Harare, Zimbabwe     

《Physics and Chemistry of the Earth》2016

The main objective in this study was to compare the physico-chemical characteristics and biota of a river (Mukuvisi) passing through an urban area to that of a non-urbanised river (Gwebi). Five sites in the Mukuvisi River and five sites in the Gwebi River were sampled for water physico-chemical parameters (pH, conductivity, DO, BOD, TDS, ammonia, Cl, SO₄²⁻, PO₄²⁻, NO₃³⁻, F⁻, Pb, Cu, Fe, Mn, Zn and Cr) once every month between August, 2012–August, 2013. Cluster analysis based on the physico-chemical parameters grouped the sites into two groups. Mukuvisi River sites formed their own grouping except for one site which was grouped with Gwebi River sites. Principal Component Analysis (PCA) was used to extract the physico-chemical parameters that account for most variations in water quality in the Mukuvisi and Gwebi Rivers. PCA identified sulphate, chloride, fluoride, iron, manganese and zinc as the major factors contributing to the variability of Mukuvisi River water quality. In the Gwebi river, sulphate, nitrate, fluoride and copper accounted for most of the variation in water quality. Canonical Correspondence Analysis (CCA) was used to explore the relationship between physico-chemical parameters and macroinvertebrate communities. CCA plots in both Mukuvisi and Gwebi Rivers showed significant relationships between macroinvertebrate communities and water quality variables. Phosphate, ammonia and nitrates were correlated with Chironomidae and Simulidae. Gwebi River had higher (P < 0.05, ANOVA) macroinvertebrates and fish diversity than Mukuvisi River. Clarias gariepinus from the Mukuvisi River had high liver histological lesions and low AChE activity and this led to lower growth rates in this river.  相似文献   

Effects of nutrient enrichment derived from fish farming activities on macroinvertebrate assemblages in a subtropical region of Hong Kong     

Gao QF  Cheung KL  Cheung SG  Shin PK 《Marine pollution bulletin》2005,51(8-12):994-1002

To study the correlation between nutrient enrichment derived from fish farming activities and changes in macrobenthic assemblages, a one-year field study was conducted in Kau Sai Bay marine fish culture zone of Hong Kong. Bimonthly sediment samples were collected at six stations: two at the fish cages, two near the boundary of the fish culture area, and two reference sites further away from the culture area. Sediment physico-chemical characteristics in terms of silt/clay fraction, moisture content, total organic carbon (TOC), total Kjeldahl nitrogen (TKN) and total phosphorus (TP) were analyzed. The macrobenthos (>0.5 mm) present in the sediment were sorted, identified and enumerated. On average, TOC, TKN and TP levels at the fish cage stations were 82.8%, 128.5% and 1315.7% higher than those at the reference stations, respectively. As a result, the N:P molar ratio was greatly reduced from 8.75 at the reference stations to 1.83 at the fish cage stations. Univariate and multivariate analyses revealed that diversity of macrofauna was significantly reduced and community structure differed at the fish cage stations relative to the reference sites. The intermediary stations near the fish culture area showed a transitional state of disturbance. Faunal diversity was negatively correlated with nutrient level, reflecting the adverse impacts of nutrient enrichment derived from fish farming activities on the benthic assemblages. Whilst in subtropical Asia-Pacific trash fish is the major feed for fish culture resulting in a higher nutrient loading and nutrient ratio accumulated in the sediment beneath the fish rafts, the effects of nutrient enrichment on macrobenthic assemblages are comparable to that in temperate waters owing to relatively high sediment metabolism rate and smaller fish culture scale in Hong Kong.  相似文献   

Seasonal variability of benthic indices: an approach to test the applicability of different indices for ecosystem quality assessment     

Reiss H  Kröncke I 《Marine pollution bulletin》2005,50(12):1490-1499

In recent studies, several benthic biological indices were developed or used to assess the ecological quality status of marine environments. In the present study the seasonal variability of several univariate and multimetric indices was studied on a monthly scale (September 2000 until May 2002) in different areas of the North Sea such as the German Bight, the Oyster Ground and the Dogger Bank. The stations were chosen to reflect a gradient in the hydrographic regime, temperature and organic matter supply. The seasonal variability was highest for the univariate indices such as the Shannon–Wiener Index and the Hurlbert Index. Thus, due to sensitivity to recruitment the corresponding ecological status ranged from ‘good’ to ‘poor’ depending on the season. For the multimetric indices such as the AMBI or the BQI the seasonal variability and the corresponding ecological status were low. The results are discussed concerning possible consequences for ecological quality assessment especially related to the Water Framework Directive (WFD).  相似文献   

西双版纳橡胶种植特点及其对热带森林景观影响的遥感研究   总被引：5，自引：0，他引：5  

张佩芳  许建初  王茂新  邓喜庆 《国土资源遥感》2006,17(3):51-55

利用遥感技术研究西双版纳橡胶分布格局、时空动态及其对热带森林景观的影响。研究表明： 西双版纳橡胶种植既有明显的地域分布和地带分布差异特征，也有很高的时空动态度； 橡胶种植对土壤侵蚀作用不明显，但是使周边环境破碎度加大，热带森林异质性自然景观向单一人工斑块化景观发展； 西双版纳橡胶种植获得了巨大的社会效益和经济效益，也对热带森林的稳定性和多样性造成威胁。  相似文献   

Vertical Distribution of Bacteria in Doroninskoe Lake(Zabaikalie,Russia):Paradigm of Dominance     

Natalia BELKOVA  Evgeniya MATYUGINA 《《地质学报》英文版》2014,88(Z1):53-55

正1 Introduction Prokaryotes are key organisms in aquatic ecosystems as they play animportant role in the biogeochemical cycling of elements.Investigations on the relationships betweenthe diversity of microbial community and environmentalfactors offer useful information that bothleads to understanding of the process of element  相似文献   

A new dragonfly family from the mid Cretaceous Burmese amber (Odonata: Aeshnoptera: Burmaeshnidae)     

《Cretaceous Research》2017

The third Cretaceous Aeshnoptera in amber is described from Myanmar. It represents a new family Burmaeshnidae fam. nov., genus and species Burmaeshna azari gen. et sp. nov. Its exact affinities remain uncertain but it is probably the sister group of the Late Cretaceous family Enigmaeshnidae. This discovery supports the hypothesis of an intense period of appearance of many aeshnopteran subclades during the late Early Cretaceous and the Late Cretaceous.  相似文献   

Re‐Connection of Oxbow Lakes as an Effective Measure of River Restoration     

《洁净——土壤、空气、水》2017,45(3)

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象山港大型底栖动物群落特征   总被引：11，自引：3，他引：8       下载免费PDF全文

顾晓英  陶磊  尤仲杰  焦海峰  施慧雄  楼丹 《海洋与湖沼》2010,41(2):208-213

2006年7月—2008年8月,对象山港全港海域设立的13个采样站位采集的调查资料,用物种丰富度指数、物种均匀度指数和物种多样性指数分析象山港大型底栖动物物种的多样性和群落种类的组成,以及采用ABC曲线方法和大型多元统计分析软件PRIMER5对象山港大型底栖动物进行Bray-Curtis相似性聚类分析和非度量MDS标序,研究象山港大型底栖动物群落结构。调查显示象山港大型底栖动物不同采样站位之间物种丰富度指数(d)、均匀度指数(J)、辛普森多样性指数(D)和香农-威纳多样性指数(H’)差异皆高度显著(P0.01)。群落结构聚类分析和MDS标序表明,13个采样站位的大型底栖动物群落大致可分为3组。根据所调查象山港大型底栖动物的丰度和生物量资料做的ABC曲线分析表明,该海域大型底栖动物群落受到了严重的环境污染或者扰动,逐渐由一种或几种个体较小的种类占优势。  相似文献