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首页> 外文期刊>Diatom Research >EPILITHIC DIATOMS FROM RHEOCRENE SPRINGS IN THE EASTERN ALPS (VORARLBERG, AUSTRIA)
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EPILITHIC DIATOMS FROM RHEOCRENE SPRINGS IN THE EASTERN ALPS (VORARLBERG, AUSTRIA)

机译：东部阿尔卑斯山脉红景天春季的流行病学对话

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摘要

Benthic epilithic diatom assemblages were studied along with physico-chemical variables from 27 spring habitats situated in the western margin mountain area of the Eastern Alps (Vorarlberg, Austria) and were collected between the years 2003-2005. Thesampling sites are situated in five of the seven aquatic ecoregions, as defined by the Austrian ecological quality assessments program of rivers. The sites occur over a wide altitudinal range (580 to 1800 m above sea level). The present study attempts totest the bioregional approach for the differentiation of rheocrene spring habitats, a spring type closely related to small running waters. Spring diatom assemblages primarily reflected the, influence of the nutrient content, altitude, flow regime and mineral content but also are differentiated on a smaller scale by the main habitat peculiarities. The most frequent and abundant taxa were common elements of alpine lotic sites, the differentiation of assemblages appeared in the subdominant or even rare taxa (e.g. omphonema occultum, Encyonopsis microcephala, Delicata delicatula). Altogether the diatom composition comprised 197 taxa with >50% typical from lotic environments and 9% crenophilous taxa (having a strong affinity to springs, e.g. Delicata delicatula, Diatoma mesodon). Nitrate concentration and pH showed the greatest effect on the species composition but site-to-site characteristics also depended on the availability of substrates (e.g. wet rocks) and/or irregular discharge. Moisture indicator values, taking into consideration the distribution of taxa linked to water level fluctuations, were given for 57% of the species found (112 taxa). Fifteen percent of these taxa were generally occurring on wet and moist or temporarily dry places (springs -Navicula strdmii, Rhopalodia gibba, moss habitats -Encyonopsis falaisensis, Pinnularia borealis) and another 4% nearly exclusively outside water bodies (e.g. Diadesmis gallica yar. perpusilla). The latter group indicated either non-permanent sites or springs emerging from unstable ground. The number of threatened taxa (25%) according to the German Red List for diatoms was less than what was expected when compared to former studies based on Southern Alpine springs (50%) or Central Germany (31%). This reduction in red list species went along with higher nitrate concentrations, irregular discharge and minor human impact, since only 50% of the sites were still undisturbed.
机译：研究了位于东部阿尔卑斯山西缘山区（奥地利福拉尔贝格州）的27个春季生境中的底栖上层硅藻组合以及其理化变量，并在2003-2005年之间进行了收集。根据奥地利河流生态质量评估计划的定义，采样地点位于七个水生生态区中的五个中。这些地点分布在很宽的海拔范围内（海拔580至1800 m）。本研究试图测试生物区域方法来区分水cre春季生境，这是一种与小型自来水密切相关的春季类型。春季硅藻的组合主要反映了养分含量，海拔高度，流态和矿物质含量的影响，但主要栖息地的特点在较小范围内也有所区别。最频繁和最丰富的分类单元是高山抽水地点的常见元素，组合的分化出现在次要的甚至罕见的分类单元中（例如，全膜隐孢子虫，小头孢囊目，德利卡塔奇纤毛）。硅藻组合物总共包含197个分类单元，其中50％以上来自于典型的抽烟环境，而9％的嗜冷分类单元（对弹簧有很强的亲和力，例如Delicata delicatula，Diatoma mesodon）。硝酸盐浓度和pH值对物种组成影响最大，但点到点的特征还取决于底物（例如湿岩石）的可用性和/或不规则排放。考虑到与水位波动相关的分类单元的分布，给出了57％的物种的水分指标值（112个分类单元）。这些类群中有15％通常发生在潮湿和暂时或干燥的地方（春季-Navicula strdmii，Rhopolodia gibba，苔藓栖息地-Encyonopsis falaisensis，Pinnularia tubealis），另外4％几乎完全在水体之外（例如Diadesmis gallica yar。perpusilla）。 ）。后一组表明非永久性站点或从不稳定地面涌出的泉水。与先前基于南部阿尔卑斯山泉水（50％）或德国中部（31％）的研究相比，根据德国红色名录的硅藻，受威胁的分类单元数量（25％）少于预期。红色名录物种的减少伴随着更高的硝酸盐浓度，不规则排放和对人类的轻微影响，因为只有50％的地点仍然不受干扰。

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