Plant biodiversity and spatial heterogeneity influences on vegetation restoration in coastal wetlands

沿海社区受到气候变化的挑战。海平面上升和风暴加剧威胁到沿海基础设施、必需品和服务的供应线以及我们区域内人类生活和本地生物多样性的总体可持续性。生态系统恢复等基于自然的方法可以提高对气候变化影响的复原力。目前恢复加拿大大西洋沿岸湿地的方法依赖于恢复潮汐流动，这通常允许自然过程和植被恢复，但我们最近表明，积极种植可以加快鱼类和野生动物栖息地的恢复，以及海岸保护功能。过去的研究还表明，恢复后的潮汐湿地可能缺乏天然潮汐湿地中的沉淀丘、池塘和小溪网络等特征，导致生物多样性恢复和海岸保护较差。恢复后的滨海湿地的植物多样性也可能低于自然湿地。通过种植增加植物多样性可以帮助湿地更快地恢复包括稳定沉积物在内的功能。新斯科舍省海岸线沿线的沿海湿地在潮汐高度(涨潮和低潮水线之间的差异)以及帮助湿地建立高程以跟上海平面上升的水中的沉淀量方面表现出很大的差异。我和我的学生将对新斯科舍省大陆海岸线上的沿海湿地进行调查，以确定沉积物数量和潮汐高度如何影响所发生的植物类型以及湿地植被对海平面上升的适应能力。我们还将进行种植试验，以确定增加植物物种的多样性是否有助于湿地提升海拔和抵御侵蚀。我们将在裸露的泥滩上创建包括沉淀丘和浅凹陷在内的特征，看看这是否会增加种子的捕获和帮助植物的建立。我们还将研究河流网络和植被斑块等较大特征的形状和大小所起的作用，以确定这些特征是否与沿海湿地的整体恢复能力有关。这项研究将有助于改进大西洋加拿大潮汐沼泽的恢复技术，并有助于我们从根本上理解生态过程在发展有弹性的沿海生态系统中的作用。这项工作将为6名硕士研究生和7名本科优秀生提供一个激励性的培训平台。

Coastal communities are challenged by climate change. Sea level rise and increased storm severity threaten coastal infrastructure, supply lines for essential goods and services, and the overall sustainability of human life and native biodiversity in our region. Nature-based approaches such as ecosystem restoration can increase resilience to the effects of climate change. Current approaches to restoring coastal wetlands in Atlantic Canada rely on restoring tidal flow, which usually allows natural process and vegetation to return, but we have recently shown that active planting can speed up the recovery of habitat for fish and wildlife, as well as coastal protection functions. Past studies also suggest that restored tidal wetlands may lack features like sediment mounds, ponds and creek networks found in natural tidal wetlands, leading to poor recovery of biodiversity and coastal protection. Restored coastal wetlands may also be lower in plant diversity than natural wetlands. Increasing plant diversity via planting may help a wetland recover functions including the stabilization of sediment faster. The coastal wetlands along Nova Scotia's coastlines show great variation in tidal height (the difference between high and low tide water lines) as well as the amount of sediment in the water that helps wetlands build elevation to keep pace with sea level rise. My students and I will survey coastal wetlands across mainland Nova Scotia coastlines to determine how sediment amount and tidal height affects the types of plants that occur and the resilience of wetland vegetation to sea level rise. We will also conduct planting experiments to determine whether increasing the diversity of plant species helps the wetland build elevation and resist erosion. We will create features including sediment mounds and shallow depressions on bare mudflats to see whether this increases the trapping of seeds and helps plant establishment. We will also examine the role of the shape and size of larger features such as creek networks and vegetation patches to determine whether these features are related to the overall resilience of coastal wetlands. This research will lead to the improvement of restoration techniques for Atlantic Canada tidal marshes, and contribute to our fundamental understanding of the role of ecological processes in the development of resilient coastal ecosystems. This work will provide a stimulating training platform for six MSc students and seven undergraduate honours students.