Biodiversity and the water cycle: can rewilding mitigate the impacts of hydrological extremes?

生物多样性和水循环：野化能否减轻极端水文的影响？

• 批准号: NE/W007460/1
• 负责人: Gemma Louise Harvey
• 金额: $ 5.1万
• 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: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW007460%2F1
• 关键词: Biodiversity; water; cycle; rewilding; mitigate

Managing and responding to floods and droughts in the UK demands vast amounts of public spending, and the frequency and severity of extreme high and low flows will increase under future climate change. Many parts of our river catchments have been heavily modified over long timescales, but there is now increasing evidence that working with natural ecosystem processes can deliver multiple environmental, social and economic benefits. The rewilding of degraded landscapes is increasing in popularity globally, and represents a vital tool in reversing biodiversity decline. The changes in biodiversity arising from rewilding also have the potential to drive wider benefits, but many of these remain largely unexplored.Rewilding is the practice of returning modified landscapes to a wilder state and may include the reintroduction of missing animal species. Approaches to rewilding are wide-ranging, but the types of biodiversity change include natural regeneration of grassland, woodland and scrubland, increased biodiversity of soil-dwelling organisms, and reintroduction of large herbivores (e.g. cattle, deer, pigs) and keystone species that have disproportionately large effects on ecosystems relative to their population size (e.g. beavers, wolves). Many of the animals and plants that recolonise rewilding projects are effective 'ecosystem engineers': organisms that are capable of modifying habitats and flows of resources in ecosystems. The presence of ecosystem engineers has been linked with increased success of environmental restoration projects.Importantly, the fundamental principles that underpin rewilding offer potential for much wider-ranging benefits to support freshwater and terrestrial natural capital assets and ecosystem services but understanding of these wider effects is limited. A key knowledge gap is understanding the capacity for rewilded landscapes to modify the water cycle and mitigate hydrological extremes. This would contribute to the evidence base for the economics of biodiversity by delivering more effective water resource and water hazard management. Rewilding, by nature and scale, will alter key elements of the water cycle. Changes to soils, vegetation and river-floodplain systems arising from rewilding will alter the movement and storage of water within landscapes. If rewilding outcomes mean that water takes slower routes through the landscape, it has the potential to make important contributions to flood and drought mitigation. Our project will explore the role that biodiversity gains from landscape rewilding play in modifying the water cycle and mitigating the impacts of hydrological extremes. We will use a review of the existing evidence from rewilding projects, other forms of landscape restoration and sustainable land management, and semi-natural ecosystems, to assess the state of the evidence for key types of rewilding-driven biodiversity change, and identify knowledge gaps and future priorities. In particular, we will answer the questions: 1. How does rewilding alter hydrological processes? 2. How do these effects differ across rewilding scenarios and environmental settings? 3. To what extent have these changes delivered measurable effects on floods and low flows? 4. Where are the gaps in knowledge across questions 1 to 3?Answering these questions will determine the ways in which rewilding influences hydrology and hydrological extremes, support decision-making in rewilding practice across public and private sectors and inform future research priorities and improved monitoring of rewilding programmes.

管理和应对英国的洪水和干旱需要大量的公共支出，在未来的气候变化下，极高和极低流量的频率和严重程度将会增加。随着时间的推移，我们的河流流域的许多部分都被严重修改，但现在有越来越多的证据表明，与自然生态系统过程合作可以带来多重环境、社会和经济利益。退化景观的重新野生在全球范围内越来越受欢迎，是扭转生物多样性下降的重要工具。重新野生带来的生物多样性变化也有可能带来更广泛的好处，但其中许多仍在很大程度上尚未开发。重新野生是指将修改后的景观恢复到更荒野的状态的做法，可能包括重新引入丢失的动物物种。重新野化的方法多种多样，但生物多样性变化的类型包括草原、林地和灌木丛的自然更新，土壤生物多样性的增加，以及大型食草动物(例如牛、鹿、猪)和关键物种的重新引入，这些物种相对于其种群规模对生态系统有不成比例的巨大影响(例如海狸、狼)。许多重新定居的动植物都是有效的“生态工程师”：能够改变生态系统中的栖息地和资源流动的有机体。生态系统工程师的存在与环境恢复项目的日益成功联系在一起。重要的是，支持重新野生化的基本原则提供了更广泛的好处，以支持淡水和陆地自然资本资产和生态系统服务，但对这些更广泛的影响的了解有限。一个关键的知识缺口是了解重新开垦的地貌改变水循环和缓解极端水文状况的能力。这将有助于提供更有效的水资源和水灾管理，从而为生物多样性经济学提供证据基础。从性质和规模上讲，重新开垦将改变水循环的关键要素。重新开垦引起的土壤、植被和河流-泛滥平原系统的变化将改变景观中的水的运动和储存。如果重新开垦的结果意味着水在地貌中走得更慢，那么它就有可能为缓解洪水和干旱做出重要贡献。我们的项目将探索从景观重新野生中获得的生物多样性在改变水循环和减轻极端水文影响方面所起的作用。我们将利用对退耕还林项目、其他形式的景观恢复和可持续土地管理以及半自然生态系统的现有证据的审查，评估由退耕还林驱动的关键类型生物多样性变化的证据状况，并确定知识差距和未来优先事项。具体来说，我们将回答以下问题：1.重新放牧如何改变水文过程？2.这些影响在不同的重新放牧情景和环境环境中有何不同？3.这些变化在多大程度上对洪水和枯水带来了可衡量的影响？4.问题1至3中的知识差距在哪里？回答这些问题将确定重新放牧对水文和水文极端的影响方式，支持公共和私营部门在重新放牧实践中的决策，并为未来的研究重点和改善对重新放牧计划的监测提供信息。

项目成果

The role of rewilding in mitigating hydrological extremes: State of the evidence

• DOI: 10.1002/wat2.1710
• 期刊: Wiley Interdisciplinary Reviews: Water
• 作者: Gemma L. Harvey;Adam T. Hartley;A. Henshaw;Zareena Khan;Stewart J. Clarke;Christopher J. Sandom;Judy England;Sara King;Orlando Venn

Rewilding and the water cycle

野化和水循环

• DOI: 10.1002/wat2.1686
• 发表时间: 2023
• 期刊: WIREs Water
• 影响因子: 8.2
• 作者: Harvey G