Relations between invertebrate drift and flow velocity in sand-bed and riffle habitats and the limits imposed by substrate stability and benthic density
Relations between invertebrate drift and flow velocity in sand-bed and riffle habitats and the limits imposed by substrate stability and benthic density
复制标题
沙床和浅滩生境中无脊椎动物漂移和流速之间的关系以及基质稳定性和底栖密度所施加的限制
DOI：
10.1899/09-096.1
复制
发表时间：
2010
影响因子：
2.4
通讯作者：
R. Batalla
中科院分区：
文献类型：
--
作者：
C. Gibbins;D. Vericat;R. Batalla
摘要底栖无脊椎动物的顺流漂流是海洋环境的一个重要特征。我们收集了90漂流样品从相邻的砂床和浅滩部分在地中海河流在低流量条件下。我们的目标是比较漂移通量（密度和瞬时漂移）和模型的漂移响应在每个栖息地的速度梯度。速度分布没有显着差异的栖息地之间，但推移质输沙率和悬浮泥沙浓度显着较高的砂床栖息地，其中基板是精细和不稳定的浅滩栖息地。底栖无脊椎动物的密度不同的栖息地之间的数量级，低和相对均匀的密度在沙床。然而，平均漂移密度并没有显着不同的栖息地。分位数回归表明，在整个速度梯度的漂移响应的上限不同的栖息地。低于这些上限的样本值表明，底质稳定性和底栖生物密度对某些地点的漂移起了限制作用。瞬时漂移是高得多的砂床比浅滩栖息地，高达42%的底栖生物存在于漂移在任何给定的时刻。底栖动物和漂流物样本的分类组成表明，浅滩的动物有助于在沙床生境漂流。沙床栖息地的高损失率表明动物的快速更替，来自上游浅滩的无脊椎动物的支持。
Abstract Downstream drift of benthic invertebrates is one of the defining characteristics of lotic environments. We collected 90 drift samples from adjacent sand-bed and riffle sections in a Mediterranean river during low flow conditions. Our goal was to compare drift fluxes (densities and instantaneous drift) and model the drift response across the velocity gradient in each habitat. Velocity distributions did not differ significantly between the habitats, but bedload transport rates and suspended sediment concentrations were significantly higher in the sand-bed habitat, where substrate was finer and less stable than in the riffle habitat. Benthic invertebrate densities differed by an order of magnitude between the habitats, with low and relatively homogeneous densities in the sand-bed. However, mean drift density did not differ significantly between the habitats. Quantile regression indicated that the upper limits of the drift response across the velocity gradient differed between habitats. Sample values below these upper limits suggest that substrate stability and benthic density act to constrain drift in some locations. Instantaneous drift was much higher in the sand-bed than in the riffle habitat, with up to 42% of the benthos present in the drift at any given moment. The taxonomic composition of benthic and drift samples suggested that animals from the riffle contributed to drift in the sand-bed habitat. The high loss rates in the sand-bed habitat suggest a rapid turnover of animals, supported by invertebrates arriving from the upstream riffle.
影响因子：
2.2
作者：
Lancaster, Jill;Downes, Barbara J.
通讯作者：
Downes, Barbara J.