3Rs of drought: resistance, resilience and recovery - an opportunistic experiment

干旱的 3R：抵抗力、复原力和恢复——机会主义实验

• 批准号: NE/X016706/1
• 负责人: John Murphy
• 金额: $ 10.28万
• 依托单位: Queen Mary University of London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX016706%2F1
• 关键词: 3Rs; drought; resistance; resilience; recovery

The summer of 2022 has seen the highest air temperatures ever recorded in England and the lowest July rainfall since 1935. This drought, the worst in Europe for 500 years, has resulted in the widespread drying of river channels over large parts of England and Wales. Whilst extreme in historic terms, the drought provides a foretaste of the conditions expected with climate change: such extreme hydroclimatic events are expected to become more frequent in the future. Our ability to predict the impact of such droughts on the biological communities living in rivers, and hence mitigate the most severe effects, is constrained by a limited understanding of the factors influencing their abilities to resist the effects of drought and to recovery once flow resumes. Here the substrate of the river bed is particularly important, as many animals will retreat into wet subsurface substrate once surface water has been lost. Without a clear understanding of how substrate characteristics affect the response of rivers to drought, river managers cannot prioritize the most vulnerable rivers for protection from drying. We are in a unique position of having an experiment already set up in multiple replicated stream channels that will enable us to experimentally examine the effects of substrate/fine sediment on the response of river communities to drought and on their potential to recolonise and recover following the resumption of flow. The experiment, set up to look at the effects of substrate composition and fine sediment loading on the macroinvertebrate communities dried naturally as water levels declined during the drought, with the treatments left in situ. We will explore how substrate characteristics influence i) the ability of invertebrates to persist through drought in the river bed, ii) the ability of invertebrates to recolonise the river by emerging from the river bed once flow resumes, and iii) the relative importance of recolonisation from the river bed compared with other routes of colonization (aerial or drifting).

2022年夏天，英格兰有史以来最高的空气温度和1935年以来的7月降雨量。这种干旱是欧洲最糟糕的500年来最糟糕的，导致了英格兰和威尔士大部分地区的河道广泛干燥。尽管从历史性的角度来看，干旱却预测了随着气候变化的预期条件：这种极端的氢化气候事件预计将来会变得更加频繁。我们预测这种干旱对河流中生物群落的影响的能力，因此减轻了最严重的影响，受到对影响其能力的因素的有限理解，以抵抗干旱的影响和恢复一旦恢复恢复。在这里，河床的底物尤为重要，因为一旦丢失了地表水，许多动物将撤退到湿的地下底物中。如果没有清楚地了解底物特征如何影响河流对干旱的反应，河流经理无法优先考虑最脆弱的河流以防止干燥。我们处于独特的位置，即在多个重复的流通道中已经建立了一个实验，这将使我们能够实验地检查底物/细沉积物对河流社区对干旱的反应以及在恢复流量后重新殖民和恢复的潜力的影响。该实验是为了研究底物成分和细沉积物负荷对大型无脊椎动物群落的影响，随着水位在干旱期间的水位下降，剩下的治疗量会自然干燥。我们将探讨底物特征如何影响i）无脊椎动物通过河床中的干旱持续存在的能力，ii）与河床一旦恢复恢复的河床，无脊椎动物通过从河床中出现而恢复河流的能力，而iiii）与其他殖民地相比，河床的相关性与其他植物相比（与其他殖民地的途径相比）。