Groundwater flooding: Groundwater community recovery following an extreme recharge event.

地下水泛滥：极端补给事件后地下水群落的恢复。

• 批准号: NE/M005151/1
• 负责人: Anne Robertson
• 金额: $ 6.57万
• 依托单位: University of Roehampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FM005151%2F1
• 关键词: Groundwater; flooding; community; recovery; following

This winter (2013-14) has been the wettest in the UK since records began resulting in extremely high groundwater levels and very extensive groundwater flooding, particularly in chalk aquifers. The exceptionally high intensity of flooding and water movement through the aquifers is expected to result in changed nutrient concentrations, including carbon. We think that these changes will have major effects on the groundwater ecosystem which, in addition to the chemical and physical environment, comprises microbial biofilms, microfauna (e.g. Protozoa, rotifers), and macroscopic invertebrates dominated by crustaceans such as copepods and Niphargus (blind shrimp-like animals). Most groundwater organisms are unique to this habitat and, in the UK, have been present for many millions of years. They mediate processes such as nitrogen recycling and thus they impact the quality of a vital source for drinking water. We think that during flooding, nutrient supplies will initially decrease due to dilution and that flow rates will increase, potentially stripping microbial biofilms and associated microfauna from the sediments and dislodging larger organisms into the water flow. This will lead to an initial reduction in biomass at each trophic level although it will not alter the overall shape of the biomass pyramid. We also expect ecosystem respiration and species and/or functional diversity to be low during flooding. When the flood ends we think that microbial biofilms, protozoa and small metazoa will recover quickly because they reproduce rapidly but that larger animals will recover more slowly if they cannot find shelter from the flood. This may result in a change in shape of the biomass pyramids. We will test these ideas by tracking the recovery of the groundwater ecosystem through space and time. We will do this by collecting samples to measure the food supply (dissolved organic carbon and other nutrients), count and identify the inhabitants of the groundwater ecosystem and also determine how ecosystem function changes by measuring respiration rates and microbial activity. We will collect samples in two separate flooded chalk aquifers at fortnightly intervals over a seven month period so that we can monitor changes in the community; we expect these to be rapid. We will use specialised equipment to measure microbial respiration and count the smallest organisms (bacteria). This extreme event permits a uniquely important case study because it will provide a baseline against which future extreme events (e.g. flooding and drought) in groundwaters can be measured and will enable us to compare the responses of groundwater ecosystems to stressors with those of other aquatic ecosystems.We hope to use the data collected in this project to apply for larger grants, possible topics for these grant applications include combining data generated in this Urgency grant with laboratory experiments that will enable us to calculate the extent to which different Groundwater assemblages (e.g. with or without macrofauna) are able to metabolise dissolved organic carbon/ nutrient loadings and thus, provide effective water quality ecosystem services of substantial ecological and economic impact to the UK.

今年冬天（2013-14）是英国有记录以来最潮湿的冬天，导致地下水位极高，地下水泛滥，特别是白垩含水层。异常高强度的洪水和含水层的水运动预计将导致包括碳在内的营养物浓度发生变化。我们认为这些变化将对地下水生态系统产生重大影响，除了化学和物理环境外，地下水生态系统还包括微生物生物膜、微型动物（如原生动物、轮虫）和以甲壳类动物为主的宏观无脊椎动物，如桡足类和盲虾。 -像动物）。大多数地下水生物都是该栖息地所特有的，在英国已经存在了数百万年。它们介导氮循环等过程，因此影响饮用水重要来源的质量。我们认为，在洪水期间，养分供应最初会因稀释而减少，流速会增加，可能会从沉积物中剥离微生物生物膜和相关的微型动物，并将较大的生物体移入水流中。这将导致每个营养级生物量的初始减少，尽管它不会改变生物量金字塔的整体形状。我们还预计洪水期间生态系统呼吸以及物种和/或功能多样性会较低。当洪水结束时，我们认为微生物生物膜、原生动物和小型后生动物会很快恢复，因为它们繁殖迅速，但较大的动物如果找不到躲避洪水的庇护所，恢复速度会更慢。这可能会导致生物质金字塔形状的变化。我们将通过时空追踪地下水生态系统的恢复来检验这些想法。为此，我们将收集样本来测量食物供应（溶解的有机碳和其他营养物质），计算和识别地下水生态系统的居民，并通过测量呼吸速率和微生物活动来确定生态系统功能的变化。我们将在七个月的时间内每两周在两个独立的被淹没的白垩含水层收集样本，以便我们能够监测社区的变化；我们预计这些会很快。我们将使用专门的设备来测量微生物呼吸并计算最小的生物体（细菌）。这一极端事件成为一个极其重要的案例研究，因为它将提供一个基线，可以根据该基线来衡量未来地下水中的极端事件（例如洪水和干旱），并使我们能够将地下水生态系统对压力源的反应与其他水生生态系统进行比较我们希望利用该项目中收集的数据来申请更大的赠款，这些赠款申请的可能主题包括将该紧急赠款中生成的数据与实验室实验相结合，这将使我们能够计算不同地下水组合的程度（例如，有或没有大型动物）能够代谢溶解的有机碳/营养物负荷，从而提供有效的水质生态系统服务，对英国产生重大生态和经济影响。

项目成果

Groundwater flooding: Ecosystem structure following an extreme recharge event.

地下水泛滥：极端补给事件后的生态系统结构。

• DOI: 10.1016/j.scitotenv.2018.10.216
• 发表时间: 2019
• 期刊: The Science of the total environment
• 作者: Reiss J