Data from: Hierarchical multi-taxa models inform riparian vs. hydrologic restoration of urban streams in a permeable landscape

The degradation of streams caused by urbanization tends to follow predictable patterns; however, there is a growing appreciation for heterogeneity in stream response to urbanization due to the local geoclimatic context. Furthermore, there is building evidence that streams in mildly sloped, permeable landscapes respond uncharacteristically to urban stress calling for a more nuanced approach to restoration. We evaluated the relative influence of local-scale riparian characteristics and catchment-scale imperviousness on the macroinvertebrate assemblages of streams in the flat, permeable urban landscape of Perth, Western Australia. Using a hierarchical multi-taxa model, we predicted the outcomes of stylized stream restoration strategies to increase the riparian integrity at the local scale or decrease the influences of imperviousness at the catchment scale. In the urban streams of Perth, we show that local-scale riparian restoration can influence the structure of macroinvertebrate assemblages to a greater degree than managing the influences of catchment-scale imperviousness. We also observed an interaction between the effect of riparian integrity and imperviousness such that the effect of increased riparian integrity was enhanced at lower levels of catchment imperviousness. This study represents one of few conducted in flat, permeable landscapes and the first aimed at informing urban stream restoration in Perth, adding to the growing appreciation for heterogeneity of the Urban Stream Syndrome and its importance for urban stream restoration.

城市化引发的溪流退化通常遵循可预测的模式；然而，受局地地质气候背景影响，人们愈发认识到溪流对城市化的响应存在异质性。此外，日益增多的证据显示，缓坡透水景观中的溪流对城市胁迫的响应表现异常，这要求采用更为精细化的修复方案。本研究以澳大利亚西部珀斯的平坦透水城市景观中的溪流为对象，评估了局地河岸带（riparian）特征与集水区尺度（catchment-scale）不透水面覆盖度（imperviousness）对溪流大型无脊椎动物群落（macroinvertebrate assemblages）的相对影响。我们采用分层多类群模型（hierarchical multi-taxa model），预测了两种预设溪流修复策略的实施效果：一是提升局地河岸带完整性，二是降低集水区尺度不透水面的影响。研究结果表明，在珀斯的城市溪流中，局地河岸带修复对大型无脊椎动物群落结构的影响程度，大于管控集水区尺度不透水面影响的效果。我们还观测到河岸带完整性与不透水面覆盖度之间存在交互效应：当集水区不透水面覆盖度较低时，提升河岸带完整性的修复效果会得到增强。本研究是在平坦透水景观中开展的同类研究中为数不多的一项，同时也是首个旨在为珀斯城市溪流修复提供决策参考的研究，进一步丰富了学界对城市溪流综合征（Urban Stream Syndrome）异质性及其对城市溪流修复重要性的认知。