Supplementary Information files for The influence of substrate type on macroinvertebrate assemblages within agricultural drainage ditches

Supplementary Information files for The influence of substrate type on macroinvertebrate assemblages within agricultural drainage ditches<br>Artificial drainage ditches are common features in lowland agricultural catchments that support a wide range of ecosystem services at the landscape scale. Current paradigms in river management suggest activities that increase habitat heterogeneity and complexity resulting in more diverse floral and faunal assemblages; however, it is not known if the same principles apply to artificial drainage ditch systems. We examined the effects of four artificial substrates, representing increasing habitat complexity and heterogeneity (bricks, gravel, netting and vegetation), on macroinvertebrate community structure within artificial drainage ditches. Each substrate type supported a distinct macroinvertebrate community highlighting the importance of habitat heterogeneity in maintaining macroinvertebrate assemblages. Each substrate type also displayed differing degrees of community heterogeneity, with gravel communities being most variable and artificial vegetation being the least. In addition, several macroinvertebrate diversity metrics increased along the gradient of artificial substrate complexity, although these differences were not statistically significant. We conclude that habitat management practices that increase habitat complexity are likely to enhance macroinvertebrate community heterogeneity within artificial drainage channels regardless of previous management activities.<br>

《农业排水沟底质类型对大型无脊椎动物群落的影响》补充信息文件
人工排水沟是低地农业集水区的常见景观设施，可在景观尺度上提供多样化的生态系统服务功能。当前河流管理领域的主流范式认为，提升栖息地异质性与复杂性的管理举措可促进动植物群落的多样性提升，但尚不清楚该原则是否同样适用于人工排水沟系统。本研究以人工排水沟内的大型无脊椎动物（macroinvertebrate）群落结构为研究对象，探究了四种代表栖息地复杂性与异质性梯度递增的人工底质（砖块、砾石、网材与人工植被）的影响。每种底质类型均支撑着独特的大型无脊椎动物群落，凸显了栖息地异质性对维持大型无脊椎动物群落的重要意义。各类底质的群落异质性程度亦存在差异，其中砾石基质对应的群落变异性最高，人工植被基质则最低。此外，随人工底质复杂性梯度升高，部分大型无脊椎动物多样性指标呈现上升趋势，但该差异未达到统计学显著性水平。本研究最终得出结论：无论既往管理措施如何，提升栖息地复杂性的生境管理举措，均可有效增强人工排水沟渠内大型无脊椎动物群落的异质性。