Shifting Seas - a gene landscape approach to understanding saltmarsh vulnerability and resilience to sea-level rise

变化的海洋——一种了解盐沼脆弱性和海平面上升恢复力的基因景观方法

• 批准号: 2739857
• 金额: --
• 依托单位: Plymouth University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2739857
• 关键词: Shifting; Seas; gene; landscape; approach

Saltmarsh is a vital component of so-called Nature based Solutions (NbS) to coastal defence, a role central to developing UK Government policy, that aims to better manage, protect and restore this habitat over the next 25 years. In order to deliver this policy, and the wider ecosystem and societal benefits that accrue, we must understand the risks and opportunities to coastal habitats from sea level rise (SLR) and associated coastal flooding and erosion. 'Shifting Seas' takes a gene to landscape scale approach to elucidate saltmarsh response to SLR, incorporating state of the art, interdisciplinary approaches including tidal hydrodynamics, geomorphology and sedimentology, plant genetics, saltmarsh ecology, field experiments and ecological modelling. We explore the following four objectivesObjective 1 - Saltmarsh zonation is generated by the different, but overlapping, ranges of individual species, reflecting their ability to tolerate factors associated with tidal submergence. Because elevation and inundation frequency exerts primary controls on a species 'fundamental' and 'realised' niche, changes to tidal range through SLR could have consequences for saltmarsh community structure and function. Saltmarshes will be surveyed to determine the range of component species, but with a particular focus on typical high- , mid-, and low- marsh species, and how key physical variables vary in tandem. This provides a baseline from which the elevation niche of each species can be set against present day position in the tidal frame (i.e. inundation frequencies, inundation duration, emergence duration) determined through a combination of UAV survey, water level measurements and tidal modelling. These data will build a niche model to predict the extent to which saltmarsh plants may occur or invade an area and the processes controlling population and community structure under different ACC and management scenarios.Objective 2 - Marsh elevation can influence the genetic diversity of component species and with it resilience to continued SLR and associated environmental factors. Moreover, genotypic variation in plant response to simulated seawater inundation signpost flooding as a potential selective filter that could eliminate key species and reduce functional sustainability, ecosystem resilience to SLR, and contribution to coastal defence. From Objective 1, we select two sites to represent typical 'high resilience' (sediment accretion matches SLR) and 'high vulnerability' (sediment accretion lags SLR) scenarios. We will use a genotype by sequencing approach for SNP discovery in polyploids to determine the population structure, genetic diversity and differentiation of selected species across the marsh elevation at the selected 'high resilience' and 'high vulnerability' sites.Objective 3 - Elucidation of the hydrodynamic properties operating at 'high resilience/vulnerability' sites, coupled with an understanding of the local distribution of key component plant species, their genetic diversity, and response to seawater immersion and sediment deposition, may reveal much about saltmarsh adaptation to SLR. 'Using the 'marsh organ' technique, we will plant different genotypes of the target plant species across an elevational gradient, the results informing a model forecasting how species- and genetic-variably influences marsh resilience / vulnerability to SLR.Objective 4 - We will deliver a spatially explicit 'opportunity mapping tool' informing management interventions necessary to support adaptation pathways for the conservation, restoration and protection of saltmarsh ecosystems. By elucidating the some of the (genetic, hydrodynamic, ecological) barriers to SLR adaptation, we provide crucial evidence needed to predict changes and risks to saltmarsh ecosystems and species, and in turn target solutions resilient to long-term sea-level change.

盐沼是所谓的基于自然的海岸防御解决方案 (NbS) 的重要组成部分，是制定英国政府政策的核心角色，旨在在未来 25 年内更好地管理、保护和恢复这一栖息地。为了实现这一政策以及由此产生的更广泛的生态系统和社会效益，我们必须了解海平面上升 (SLR) 以及相关的沿海洪水和侵蚀给沿海栖息地带来的风险和机遇。 “转变海洋”采用基因到景观尺度的方法来阐明盐沼对 SLR 的反应，结合了最先进的跨学科方法，包括潮汐流体动力学、地貌学和沉积学、植物遗传学、盐沼生态学、现场实验和生态建模。我们探索以下四个目标： 目标 1 - 盐沼地带是由不同但重叠的个体物种范围产生的，反映了它们耐受潮汐淹没相关因素的能力。由于海拔和洪水频率对物种的“基本”和“实现”生态位发挥主要控制作用，因此通过 SLR 改变潮汐范围可能会对盐沼群落结构和功能产生影响。将调查盐沼以确定组成物种的范围，但特别关注典型的高沼泽、中沼泽和低沼泽物种，以及关键物理变量如何串联变化。这提供了一个基线，可以根据潮汐框架中当前的位置（即淹没频率、淹没持续时间、出现持续时间）设置每个物种的海拔生态位，该潮汐框架是通过无人机调查、水位测量和潮汐建模相结合确定的。这些数据将建立一个生态位模型来预测盐沼植物可能发生或入侵一个地区的程度以及在不同的ACC和管理情景下控制种群和群落结构的过程。目标2 - 沼泽海拔可以影响组成物种和物种的遗传多样性具有对持续单反和相关环境因素的适应能力。此外，植物对模拟海水淹没路标洪水反应的基因型变异可以作为潜在的选择性过滤器，消除关键物种并降低功能可持续性、生态系统对SLR的恢复力以及对海岸防御的贡献。从目标 1 中，我们选择两个地点来代表典型的“高恢复力”（沉积物堆积与 SLR 匹配）和“高脆弱性”（沉积物堆积滞后于 SLR）场景。我们将使用基因型测序方法在多倍体中发现 SNP，以确定在选定的“高复原力”和“高脆弱性”地点的沼泽海拔上选定物种的种群结构、遗传多样性和分化。 目标 3 - 阐明在“高复原力/脆弱性”地点运行的水动力特性，再加上对关键植物物种的当地分布、其遗传多样性以及对海水浸泡和沉积物沉积的响应的了解，可能会揭示更多关于盐沼的信息适应单反。 “使用‘沼泽器官’技术，我们将在海拔梯度上种植目标植物物种的不同基因型，结果为预测物种和遗传变量如何影响沼泽恢复力/对 SLR 的脆弱性的模型提供信息。目标 4 - 我们将提供空间明确的“机会绘图工具”，为支持盐沼生态系统的保护、恢复和保护的适应途径提供必要的管理干预措施。通过阐明 SLR 适应的一些（遗传、水动力、生态）障碍，我们提供了预测盐沼生态系统和物种的变化和风险所需的关键证据，进而制定了适应长期海平面变化的解决方案。