Existing in plenty: abundance, biomass and diversity of ciliates and meiofauna in small streams
Existing in plenty: abundance, biomass and diversity of ciliates and meiofauna in small streams
复制标题
数量充足：小溪中纤毛虫和小型动物的丰度、生物量和多样性
DOI：
--
复制
发表时间：
2008
期刊：
影响因子：
--
通讯作者：
J. M. Schmid
中科院分区：
文献类型：
--
作者：
J. Reiss;J. M. Schmid
总结1。在一年的时间里，使用高分类学分辨率，研究了英格兰东南部两条对比鲜明的低地溪流的纤毛虫和后生动物的小动物组合。在2003年3月至2004年2月期间，每月从低营养、酸性河流（Lone Oak）和环中性、营养丰富的河流（Pant）中采集样本。2. 我们评估了纤毛虫和轮虫在小型底栖动物组合中的相对重要性，包括它们的丰度、生物量和物种丰富度。此外，我们还在两个分类分辨率（种和群）水平上考察了非生物和生物参数以及季节对组合组成的影响。3. 在数量上占主导地位的是纤毛虫，最大密度分别超过90万和600万头(m)2。轮虫和线虫在小虫密度中占主导地位，但它们对总小虫生物量的贡献较低（独橡树的最大生物量为71.9 mgC m）2，而大松林的最大生物量为646.8 mgC m)2)，轮虫的生物量与毛虫相当。4. 虽然两河在纤毛虫和小动物的总丰度上存在差异，并且只有7%的物种共享，但类群的相对比例是相似的。沉积物粒度分布（百分位数代表0.5-1 mm分数）与物种水平上的组合结构相关，揭示了这些小生物与其物理环境之间的紧密耦合。类群相对丰度的季节变化遵循相似的模式，并与双曲线桡足类丰度和温度相关。5. 这些高度丰富但经常被忽视的动物群的信息对于估计底栖动物的总体丰度、生物量、物种丰富度和生产力至关重要，因此对水生研究的几个领域具有重要意义，例如对那些处理营养动力学的领域。
SUMMARY 1. The ciliate and metazoan meiofaunal assemblages of two contrasting lowland streams in south-east England were examined over the period of a year, using a high taxonomic resolution. Monthly samples were taken from an oligotrophic, acid stream (Lone Oak) and a circumneutral, nutrient-rich stream (Pant) between March 2003 and February 2004. 2. We assessed the relative importance of ciliates and rotifers within the small-sized benthic assemblage with respect to their abundance, biomass and species richness. In addition, we examined the influence of abiotic and biotic parameters and season on the assemblage composition at two levels of taxonomic resolution (species and groups). 3. Ciliates dominated the assemblages numerically, with maximum densities of over 900 000 and 6 000 000 ind. m )2 in Lone Oak and Pant respectively. Rotifers and nematodes dominated meiofaunal densities, although their contribution to total meiofaunal biomass (maxima of 71.9 mgC m )2 in Lone Oak and of 646.8 mgC m )2 in the Pant) was low and rotifer biomass equalled that of ciliates. 4. Although the two streams differed in terms of total abundance of ciliates and meiofauna and shared only 7% of species, the relative proportion of groups was similar. Sediment grain size distribution (the percentile representing the 0.5–1 mm fraction) was correlated with assemblage structure at the species level, revealing the tight coupling between these small organisms and their physical environment. Seasonal changes in the relative abundance of groups followed similar patterns in both streams, and were correlated with the abundance of cyclopoid copepods and temperature. 5. Information on these highly abundant but often overlooked faunal groups is essential for estimates of overall abundance, biomass, species richness and productivity in the benthos, and as such has important implications for several areas of aquatic research, e.g. for those dealing with trophic dynamics.