Universidade de Lisboa, Instituto Superior de Agronomia, Centro de Estudos Florestais (CEF), Tapada da Ajuda, 1349-017 Lisboa, Portugal.
Universidade de Lisboa, Instituto Superior de Agronomia, Centro de Estudos Florestais (CEF), Tapada da Ajuda, 1349-017 Lisboa, Portugal; CEris - Civil Engineering for Research and Innovation for Sustainability, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.
Sci Total Environ. 2016 Aug 15;562:435-445. doi: 10.1016/j.scitotenv.2016.03.188. Epub 2016 Apr 19.
Climate change will predictably change hydrological patterns and processes at the catchment scale, with impacts on habitat conditions for fish. The main goal of this study is to assess how shifts in fish habitat favourability under climate change scenarios are affected by hydrological stressors. The interplay between climate and hydrological stressors has important implications in river management under climate change because management actions to control hydrological parameters are more feasible than controlling climate. This study was carried out in the Tamega catchment of the Douro basin. A set of hydrological stressor variables were generated through a process-based modelling based on current climate data (2008-2014) and also considering a high-end future climate change scenario. The resulting parameters, along with climatic and site-descriptor variables were used as explanatory variables in empirical habitat models for nine fish species using boosted regression trees. Models were calibrated for the whole Douro basin using 254 fish sampling sites and predictions under future climate change scenarios were made for the Tamega catchment. Results show that models using climatic variables but not hydrological stressors produce more stringent predictions of future favourability, predicting more distribution contractions or stronger range shifts. The use of hydrological stressors strongly influences projections of habitat favourability shifts; the integration of these stressors in the models thinned shifts in range due to climate change. Hydrological stressors were retained in the models for most species and had a high importance, demonstrating that it is important to integrate hydrology in studies of impacts of climate change on freshwater fishes. This is a relevant result because it means that management actions to control hydrological parameters in rivers will have an impact on the effects of climate change and may potentially be helpful to mitigate its negative effects on fish populations and assemblages.
气候变化将可预测地改变集水区尺度的水文格局和过程，从而影响鱼类的生境条件。本研究的主要目标是评估在气候变化情景下，鱼类生境适宜度的变化如何受到水文胁迫因素的影响。在气候变化下的河流管理中，气候和水文胁迫因素之间的相互作用具有重要意义，因为控制水文参数的管理措施比控制气候更为可行。本研究在杜罗流域的塔梅加集水区进行。通过基于当前气候数据（2008-2014 年）并考虑高-end 未来气候变化情景的基于过程的建模，生成了一组水文胁迫变量。将这些参数与气候和站点描述变量一起，用于使用 boosted 回归树为 9 种鱼类的经验生境模型作为解释变量。使用整个杜罗流域的 254 个鱼类采样点对模型进行校准，并对塔梅加集水区进行未来气候变化情景下的预测。结果表明，使用气候变量但不使用水文胁迫因素的模型对未来适宜度的预测更为严格，预测的分布收缩或范围转移更为强烈。水文胁迫因素的使用强烈影响生境适宜度变化的预测；在模型中整合这些胁迫因素会因气候变化而减少范围变化。大多数物种的模型中都保留了水文胁迫因素，且其重要性很高，这表明在研究气候变化对淡水鱼类的影响时，将水文学纳入研究是很重要的。这是一个相关的结果，因为这意味着控制河流水文参数的管理措施将对气候变化的影响产生影响，并可能有助于减轻其对鱼类种群和群落的负面影响。
