Melbourne Water Corporation, Docklands, Victoria, Australia.
School of Ecosystem and Forest Sciences, The University of Melbourne, Burnley, Victoria, Australia.
Glob Chang Biol. 2022 Feb;28(4):1287-1300. doi: 10.1111/gcb.16015. Epub 2021 Dec 16.
Globally, urban expansion and climate change interact to threaten stream ecosystems and are accelerating the loss of aquatic biodiversity. Waterway managers urgently need tools to understand the potential combined impacts of urbanization and climate change and to identify effective mitigating management interventions for protecting freshwater biota. We address this challenge using the semi-aquatic mammal the platypus (Ornithorhynchus anatinus) as a focal species. We developed high-resolution environmental spatial data for stream networks and spatially explicit habitat suitability models (HSMs) to explore the impact of threats and to identify the combination of management actions most likely to maintain or improve habitat suitability over the next 50 years in greater Melbourne, Australia. We developed and evaluated platypus HSMs (males-and-females and females-only) including validation using an independent environmental DNA data set. Platypus occurred more commonly in larger, cooler streams with greater catchment-weighted discharge, following periods of greater stream flow. They were positively associated with near-stream forest cover and negatively associated with annual air temperature and urban stormwater runoff. Extensive reductions in suitable platypus habitat are predicted to occur under urbanization and climate change scenarios, with the greatest threat expected from reduced streamflows. This emphasizes the importance of maintaining flow regimes as part of conserving platypus in the region; however, substantial additional benefit is predicted by concurrent riparian revegetation and urban stormwater management efforts (that also have the potential to contribute to the streamflow objectives). Provision of adequate streamflows in a future with increasing water demands and water security requirements will likely require creative integrated water management solutions. Our high-resolution stream network and HSMs have allowed predictions of potential range-shifts due to urban expansion and climate change impacts at management-relevant scales and at the whole-of-landscape scale. This has enabled systematic strategic planning, priority action planning and target setting in strategic policy development.
从全球范围来看，城市扩张和气候变化相互作用，威胁着溪流生态系统，并加速了水生生物多样性的丧失。水道管理者迫切需要工具来了解城市化和气候变化的潜在综合影响，并确定保护淡水生物群的有效缓解管理干预措施。我们以半水生哺乳动物鸭嘴兽（Ornithorhynchus anatinus）为重点物种来应对这一挑战。我们开发了用于溪流网络的高分辨率环境空间数据和具有空间显式适宜性模型（HSM），以探索威胁的影响，并确定在未来 50 年内最有可能维持或改善大墨尔本地区栖息地适宜性的管理行动组合。我们开发并评估了鸭嘴兽 HSM（雄性和雌性以及仅雌性），包括使用独立的环境 DNA 数据集进行验证。鸭嘴兽在更大、更凉爽、集水区加权排放量更大、溪流流量更大的溪流中更为常见。它们与近溪流的森林覆盖度呈正相关，与年平均气温和城市雨水径流呈负相关。预计在城市化和气候变化情景下，鸭嘴兽适宜栖息地将大量减少，预计最大的威胁来自于溪流流量减少。这强调了维持水流模式对于保护该地区鸭嘴兽的重要性；然而，同时进行河岸植被恢复和城市雨水管理工作预计会带来更大的好处（这也有可能有助于实现水流目标）。在未来用水需求和水安全要求不断增加的情况下，提供充足的水流可能需要创造性的综合水资源管理解决方案。我们的高分辨率溪流网络和 HSM 使得可以在管理相关尺度和整个景观尺度上预测由于城市扩张和气候变化影响而导致的潜在范围转移。这使得能够进行系统的战略规划、优先行动计划和战略政策制定中的目标设定。
