Sensitivity of river ecosystems to global change: Assessing land management strategies to mitigate the combined impacts of climate warming and land use changes in cold temperate regions

河流生态系统对全球变化的敏感性：评估土地管理策略，以减轻寒温带地区气候变暖和土地利用变化的综合影响

• 批准号: RGPIN-2017-06571
• 负责人: Campeau, Stéphane
• 金额: $ 1.6万
• 依托单位: Université du Québec à Trois-Rivières
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=765341
• 关键词: Sensitivity; river; ecosystems; global; change

How climate-induced warming will interact with future land use changes remains largely unknown. Most studies that have attempted to forecast the effect of climatic changes on hydrology and water quality consider that watershed configuration would not be altered. However, it is likely that land use will continue to evolve over the next decades and that it will have an important influence on future watershed hydrology and water quality. Future climatic changes, combined with land use modifications and land management practices will create complex interactions and feedbacks in aquatic ecosystems.The long-term objectives of this research program are to examine the sensitivity of river benthic algae (diatoms) to the combined impacts of climatic and land use changes and to evaluate the efficiency of a set of mitigation strategies to maintain the integrity of river ecosystems. To fulfill the objectives of this research program, three methodological approaches are proposed, involving different study designs and temporal and spatial scales. First, the relationships between benthic diatoms and environmental factors (water temperature and flow, sediment and nutrient regimes) will be investigated empirically and at a large spatial scale based on data from a monitoring network extending over more than 800 stream reaches in Eastern Canada. Second, the relationships between benthic diatoms and environmental factors will be tested by means of periphyton experiments in stream mesocosms. Finally, the combined impact of global change scenarios on river benthic diatoms will be investigated using a watershed model (GIBSI), whereby a calibrated hydrological model will be forced with climatic inputs representing several global warming scenarios. In addition to climate simulations, land use and mitigation scenarios will be applied for testing the effects of specific socio-economic measures aimed at reducing point or diffuse nutrient emissions.Although there is a wide consensus about climatic warming, there is less certainty about the likely impacts on water quality and river ecosystems due to changes in regional precipitation and land use. The results of this research program will enable stakeholders to develop strategies to better adapt to climate change impacts and enhance the ecological integrity of Eastern Canadian rivers. Designs for new farming practices and land use planning will have to incorporate climate change effects, and new operational procedures may be required. Our findings will be useful to define plans for long-term land use zoning that is protective of water quality under a changing climate. The results of this research could be quickly incorporated into practice as part of our collaborations with the stakeholders of 80 agricultural watersheds undergoing algae-based monitoring.

气候导致的气候变暖将如何与未来的土地利用变化相互作用在很大程度上尚不清楚。大多数试图预测气候变化对水文和水质的影响的研究都认为分水岭的配置不会改变。然而，土地利用很可能在未来几十年中继续演变，并将对未来的流域水文和水质产生重要影响。未来气候变化，结合土地利用变化和土地管理措施，将在水生生态系统中产生复杂的相互作用和反馈。本研究计划的长期目标是研究河底藻类(硅藻)对气候和土地利用变化综合影响的敏感性，并评估一套缓解策略的有效性，以维持河流生态系统的完整性。为了实现本研究计划的目标，本研究提出了三种方法，涉及不同的研究设计和时间和空间尺度。首先，将基于加拿大东部800多条河流的监测网络的数据，对底栖硅藻与环境因素(水温和水流、沉积物和营养状况)之间的关系进行大空间尺度的经验性研究。其次，将通过水系中的围生实验来检验底栖硅藻与环境因子的关系。最后，将使用分水岭模型(GIBSI)研究全球变化情景对河流底栖硅藻的综合影响，根据该模型，将用代表几种全球变暖情景的气候输入强制建立校准的水文模型。除了气候模拟外，还将利用土地利用和缓解情景来测试旨在减少点状或弥漫养分排放的具体社会经济措施的效果。尽管对气候变暖有广泛的共识，但区域降水和土地利用的变化对水质和河流生态系统可能产生的影响尚不确定。这一研究计划的结果将使利益相关者能够制定战略，以更好地适应气候变化的影响，并增强加拿大东部河流的生态完整性。新的耕作方式和土地利用规划的设计必须考虑气候变化的影响，并可能需要新的操作程序。我们的发现将有助于确定长期土地用途分区计划，以保护气候变化下的水质。这项研究的结果可能很快被纳入实践，作为我们与80个正在进行藻类监测的农业流域的利益攸关方合作的一部分。