Compounding effects of agricultural land use and water use in free-flowing rivers: confounding issues for water management

摘要: Defining the ecological impacts of water extraction from free-flowing river systems in altered landscapes is challenging as multiple stressors (e.g. flow regime alteration, increased sedimentation) may have simultaneous effects and attributing causality problematic. Furthermore, patterns pumping timing rates) govern characteristics hydrologic responses. We examined land use on rivers upper Ringarooma River catchment Tasmania (south-east Australia), which contains intensively-irrigated agriculture, to support implementation a Water Management Plan (WMP). Temporal trends condition were assessed using 19-year dataset macroinvertebrate community monitoring. Macroinvertebrates also sampled at 19 sites before after dry irrigation season 2012/13, while spatial datasets used characterize study having upstream sub-catchments with: (1) low agricultural use, (2) high or (3) use. In addition, response communities edge thalweg microhabitats diel variability was investigated with stable variable baseflows. extraction-related found exacerbate impairment associated reduced density, more avoiding taxa). Increased relating appeared contribute degradation by making habitat uninhabitable for many taxa. These findings need implement WMP accordance its environmental thresholds, allocation limits adaptive management provisions. To inform an process, further surveillance monitoring targeted research test effectiveness strategies being be conducted.