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981.
Ecology of macrobenthos in the south of Zhejiang coastal waters 总被引:1,自引:0,他引:1
为了解浙江南部近岸海域海洋生态环境质量的现状及其变化趋势,2009年4月对浙江南部近岸海域的12个站位进行了大型底栖生物的分类、组成、丰度、生物量以及多样性的研究.应用Bray—Curtis相似性系数聚类和多维尺度排序,对浙江南部近岸海域的大型底栖生物进行群落划分;采用丰度生物量比较法分析群落的稳定性;并研究了对大型底栖生物产生影响的主要环境因子.本次调查共鉴定大型底栖生物109种,多毛类、软体动物和甲壳动物构成主要类群.平均生物量为23.38g/m^2,平均丰度为335.5ind/m^2,平均生物多样性指数为2.69.数量组成:生物量以软体动物居首(13.29g/m^2),鱼类次之(3.68g/m^2);丰度以多毛类居首(268.0ind/m^2),软体动物次之(51.7ind/m^2).浙江南部近岸海域可划分为3个群落.与环境因子进行相关性分析表明,有机污染含量、深度、溶解氧含量、盐度和悬浮物含量是对浙江南部近岸海域大型底栖生物产生影响的主要环境因子.总体上,除了瓯江口和乐清湾海域受到一定扰动,浙江南部近岸海域大型底栖生物环境质量较好,群落结构较为稳定. 相似文献
982.
983.
984.
Ciliated protozoa play important roles in micro-ecosystems, especially in marine biotopes. However, few studies have been carried out on the periphytic, or aufwuch, forms in mariculture waters so far. In this study, we sampled periphytic ciliate communities in two closed mariculture ponds (ponds CP1 and CP2) and a natural seawater reservoir (pond RP) using a glass slide method to evaluate their colonizing processes and general ecological features, as well as their application as water quality indicators. We analyzed species compositions, structural parameters (species number, richness, diversity, evenness, abundance and dBP) and functional parameters (G, Seq and T90%). Pond RP was characterized by higher levels of structural parameters (except for abundance and dBP) and more equal proportion of the major taxonomic groups. The values of Seq were significantly higher in pond RP and similar in both pond CP1 and CP2. It was also demonstrated that environmental factors, including NO2-H, NO3-H, NH3-H, soluble reactive phosphate, temperature and pH, were the first principal factors affecting the communities. Among them, temperature and chemical factors were all significantly and negatively correlated with species number (P<0.01), richness (P<0.01), diversity (P<0.01), and positive correlated with abundance (P<0.01). Opposite correlations between pH and structural parameters were observed. This study showed that there were significant differences in species composition, structural parameters and functional parameters of the periphytic ciliate communities among the ponds, which were in agreement with the water quality. Results of this study confirmed the periphytic ciliate communities to be useful bioindicators of water quality in intensive mariculture waters. 相似文献
985.
M. Söffker K.A. SlomanJ.M. Hall-Spencer 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(8):818-825
The abundance and behaviour of fish on and around coral reefs at Twin Mounds and Giant Mounds, carbonate mounds located on the continental shelf off Ireland (600-1100 m), were studied using two Remotely Operated Vehicle (ROV) dives. We recorded 30 fish taxa on the dives, together with three species of Scleractinia (Lophelia pertusa, Madrepora oculata and Desmophyllum cristagalli) and a diverse range of other corals (Antipatharia, Alcyonacea, and Stylasteridae). Stands of live coral provided the only habitat in which Guttigadus latifrons was observed whereas Neocyttus helgae was found predominantly on structural habitats provided by dead coral. Significantly more fish were found on structurally complex coral rubble habitats than on flatter areas where coral rubble was clogged with sand. The most common species recorded was Lepidion eques (2136 individuals), which always occurred a few cm above bottom and was significantly more active on the reefs than on sedimentary habitats. Synaphobranchus kaupii (1157 indiv.), N. helgae (198 indiv.) and Micromesistius poutassou (116 indiv.) were also common; S. kaupii did not exhibit habitat-related differences in behaviour, whilst N. helgae was more active over the reefs and other structured habitats whereas M. poutassou was more active with decreasing habitat complexity. Trawl damage and abandoned fishing gear was observed at both sites. We conclude that Irish coral reefs provide complex habitats that are home to a diverse assemblage of fish utilising the range of niches occurring both above and within the reef structure. 相似文献
986.
西藏乌柳群落特征 总被引:2,自引:0,他引:2
以一江两河流域为研究区,通过对西藏乌柳群落的典型地块设置11个标准地进行调查,分别从主要优势树种表现、物种组成、物种多样性、林分生长、地径结构、树高结构和树高-地径曲线等方面,分析了西藏乌柳群落的主要群落学和测树学特征。研究结构表明,1.西藏乌柳群落物种组成较为单一,群落中的物种数一般为1~4种,优势树种在群落中所占的比例较大,均大于85%;2.地径主要分布于5.0 cm以下,树高分布于1.0~5.0 m间,树高-地径服从二次曲线分布;3.由于群落物种组成较为单一,香农物种多样性指数均<1,SW和S、E的变化趋势大致相同,且与ED变化趋势相反。 相似文献
987.
988.
旅游扶贫中社区居民态度的分异与主要矛盾——以中俄边境村落室韦为例 总被引:2,自引:1,他引:1
错综的矛盾常令以旅游业扶贫的乡村很快面临发展的瓶颈。以内蒙古边境村落室韦为例,以身处贫困漩涡中心的社区居民为研究对象,根据居民介入当地“家庭游”时间不同分为3组,通过深度访谈和问卷调查,剖析不同居民在旅游的经济、社会和文化影响感知方面的差异,从社区居民态度角度揭示出困扰当地旅游发展的三对主要矛盾,即负向的经济影响感知与... 相似文献
989.
DUAN Ye Institute ofMesozoic Palaeontology of Western Liaoning Shenyang Normal University Shenyang Liaoning China 《东北亚地学研究》2005,(Z1)
Middle and Late Cambrian trilobite faunas from the Dama section in western Hunanare are composed of 63 genera and subgenera, 84 species, and two forms of gen. et sp. indetermined. Which include a mixture of cosmopolitan agnostoids and polymeroids. Three new species, Hardyoides damaensis ,Meringaspis damaensis and Rhyssomelopus (Rodtrifinis ) nitidus, are described by present author in 2004. Besides, Erixanium is recognised for the first time in study area, which is significant for biostratigraphical correlation of the Late Cambrian in the Austalo-Asia region. According to distribution regularity vertical, the Middle and Late Cambrian trilobites can be divided into 9 trilobite communities for the Dama section. Based on the trilobite communities analysis, the author concludes that from the east Mt. Lailong to Dama through Fenghuang, further east, reach in Chenxi.the palaeoenvironments were changed from a shallow-water of oxygen-rich (platform margin slope) into a deep-water of oxygen-poor setting (basin). 相似文献
990.
The composition and distribution of the benthic communities at the shelfbreak and upper slope of the Ubatuba region (south-eastern Brazil) were studied from a limited set of 15 dredge hauls taken between 130 and 600 m depth. Data analysis using multivariate methods showed the presence of three distinct benthic associations, related to depth and substratum. The first, between 130 and 180 m depth, was associated with the presence of large amounts of calcareous algal blocks, serving as a shelter for most of the organisms sampled, as well as an important substratum for sessile and filter-feeding animals. The second association was from the slope (240–350 m) comprising organisms exclusive to that area, and species common on shallower stations. The major faunal changes were observed in the third association at 500 m, which presented a fauna totally distinct from the former regions. It is suggested that this area is probably an upper limit for deep-living organisms in the region. 相似文献