Artificial channels are common features in lowland agricultural catchments, and are a potentially significant habitat for aquatic species. Recent studies have suggested communities in managed rivers and artificial channels are broadly similar, but with some compositional differences. However, because relatively few studies have considered how artificial channels may contribute to supporting aquatic communities, their physicochemical condition and suitability for aquatic fauna remain poorly characterised. Therefore, this study explores the role of physicochemical variables in driving macroinvertebrate community differences between intensively managed rivers and artificial channels in a highly arable catchment. Aquatic macroinvertebrates were sampled in intensively managed rivers and artificial channels. Physicochemical water quality variables were also recorded, and used to identify macroinvertebrate community responses. Both intensively managed rivers and artificial channels had spatiotemporally stable communities, with no significant differences in richness, abundance, effective diversity or Berger–Parker dominance detected between sampling months or channel types. Macroinvertebrate composition in intensively managed rivers and artificial channels was significantly different, and driven by the relative abundance of taxa present, not the number of taxa unique to each channel type. Compositional differences between intensively managed rivers and artificial channels were partially driven by conductivity, dissolved oxygen and temperature. Identifying remaining sources of compositional variance may support tailored management strategies that accentuate compositional differences between rivers and artificial channels, increasing overall diversity in intensively farmed arable catchments.

中文翻译：

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受管理的河流和农业排水渠大型无脊椎动物群落的理化驱动因素

人工渠道是低地农业流域的共同特征，并且是水生物种的潜在重要栖息地。最近的研究表明，受管理的河流和人工河道中的群落大致相似，但成分有所不同。但是，由于相对较少的研究考虑了人工渠道如何为水生生物群落提供支持，因此其理化条件和对水生动物的适应性仍然很差。因此，本研究探讨了物理化学变量在驱动高度集约化流域中集约化管理河流和人工河道之间的大型无脊椎动物群落差异中的作用。在集约化管理的河流和人工河道中对水生大型无脊椎动物进行了采样。还记录了物理化学水质变量，并将其用于识别大型无脊椎动物群落的反应。集约化管理的河流和人工河道均具有时空稳定的群落，在取样月份或河道类型之间检测到的丰富度，丰度，有效多样性或Berger-Parker优势均无显着差异。在集约化管理的河流和人工河道中，大型无脊椎动物的组成存在显着差异，其驱动因素是存在的相对分类单元数量相对丰富，而不是每种通道类型所独有的分类单元数量。集约化管理的河流和人工河道之间的成分差异部分是由电导率，溶解氧和温度驱动的。