BRC-BIO: Diverse Undergraduate Research Students in Ecology (DURSiE)

堰洲岛很容易受到风暴侵蚀、沉积物流失和海平面上升的影响，这些因素在过去几十年里都有所增加。沙子自然地随着风、浪和潮汐在岛屿上移动，而植物则将沙子固定在适当的位置。通常情况下，草类对盐和沙埋有更高的耐受性，而许多树木和灌木更容易因暴露而死亡。然而，最近，对盐敏感的灌木已经扩展到沿海草原，并且可能受益于与真菌的关系，这种真菌在某些条件下可以最大限度地减少盐的吸收。当灌木取代草时，岛屿变得更加脆弱，因为灌木抵抗侵蚀，从而阻碍岛屿的自然迁移，导致岛屿破碎。如果没有堰洲岛，大陆将处于沿海风暴的前沿，可能导致更大的生命和财产损失。在本研究中，将通过将灌木暴露于含盐条件和掩埋来模拟风暴事件。将分析灌木根系真菌感染的存在和程度，并测量根和梢的生长情况。确定灌木向草原扩张的制约因素对于预测和管理堰洲岛的未来是必要的。该研究的更广泛影响包括通过实地研究经验和植物学课程的课程研究培养多样化的学生骨干。研究生还将作为榜样，与宾夕法尼亚州当地中学的年轻学生一起学习气候变化的影响。木本植物对草原的侵占在世界范围内迅速增加；然而，这在堰洲岛上尤其有害，那里的植被类型有助于生态系统的结构和功能。在弗吉尼亚堰洲岛上，由于非生物环境的变化，原生灌木莫雷拉（Morella cerifera）正在侵入草原。关于植物组成、禾草和灌木的功能性状以及菌根关系如何随干扰而变化的知识差距仍然存在。本项目将采用野外调查、田间试验和温室试验相结合的方法，研究1)禾本科植物和白僵菌的分布沿过渡梯度的变化，2)加速干扰对禾本科植物和白僵菌功能性状的影响，3)加速干扰对禾本科植物和白僵菌菌根定植的影响。通过更好地了解生态群落如何应对和推动环境变化，该项目可以帮助沿海土地管理者更好地预测和管理堰洲岛的未来。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Barrier islands are vulnerable to storm erosion, sediment loss, and sea level rise, which have all increased during the past decades. Sand naturally moves on islands from wind, waves, and tides, while plants hold sand in place. Typically, grasses have higher tolerance to salt and sand burial whereas many trees and shrubs are more likely to die with exposure. Recently, however, salt sensitive shrubs have expanded into coastal grasslands and may be benefiting from a relationship with a fungus that minimizes salt uptake in some conditions. Islands become more vulnerable when shrubs replace grasses because shrubs resist erosion and thus impede the natural migration of islands leading to island fragmentation. Without barrier islands, the mainland would be at the forefront of coastal storms potentially leading to greater loss of life and property. In this study, storm events will be simulated through exposing shrubs to salty conditions and burial. Shrub roots will be analyzed for the presence and extent of fungus infection and root and shoot growth will be measured. Determining the constraints on shrub expansion into grasslands is necessary to predict and manage the future of barrier islands. Broader impacts of the research include training a diverse cadre of students via field research experiences and through course-based research in a Botany course. Research students will also serve as role models while engaging younger students at local middle schools in Pennsylvania to learn about the impacts of climate change.Woody plant encroachment into grasslands has rapidly increased worldwide; however, this is particularly detrimental on barrier islands, where vegetation type contributes to the structure and function of the ecosystem. On Virginia barrier islands, the native shrub, Morella cerifera is encroaching into grasslands due in part to changes in the abiotic environment. A knowledge gap remains about how plant composition, functional traits of grasses and shrubs, and mycorrhizal relationships change with disturbance. This project will combine field surveys, field experiments, and greenhouse experiments to investigate 1) the distribution of M. cerifera and grasses change along a transitional gradient, 2) the impact of accelerated disturbance on the functional traits of grasses and M. cerifera, and 3) the impact of accelerated disturbance on mycorrhizal colonization of grasses and M. cerifera. By better understanding how ecological communities will respond to and drive environmental change, this project can help coastal land managers better predict and manage the future of barrier islands.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.