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

堰塞岛容易受到风暴侵蚀、泥沙流失和海平面上升的影响，这些都在过去几十年里有所增加。沙子自然地从风、浪和潮汐中在岛屿上移动，而植物将沙子固定在原地。通常情况下，草对盐和沙埋的耐受性更高，而许多树木和灌木更有可能因暴露而死亡。然而，最近，对盐分敏感的灌木已经扩展到沿海草原，并可能受益于与一种真菌的关系，这种真菌在某些情况下最大限度地减少了盐分的吸收。当灌木取代草类时，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徙，导致岛屿碎片化。如果没有堰塞岛，大陆将处于沿海风暴的前沿，可能会导致更大的生命和财产损失。在这项研究中，将通过将灌木暴露在含盐条件下和埋葬来模拟风暴事件。将分析灌木根部真菌感染的存在和程度，并测量根和地上部的生长。为了预测和管理障碍岛的未来，有必要确定灌木扩展到草原的制约因素。这项研究的更广泛影响包括通过实地研究经验和植物学课程中基于课程的研究培养不同的学生队伍。研究学生也将成为榜样，同时让宾夕法尼亚州当地中学的年轻学生学习气候变化的影响。木本植物对草原的侵蚀在全球范围内迅速增加；然而，这在障碍岛上尤其有害，因为那里的植被类型对生态系统的结构和功能做出了贡献。在弗吉尼亚州的障碍岛上，当地的灌木莫雷拉正在侵蚀草原，部分原因是非生物环境的变化。关于植物组成、草和灌木的功能特征以及菌根关系如何随着干扰而变化的知识缺口仍然存在。本项目将结合野外调查、田间试验和温室试验，研究1)马尾草和牧草的分布沿过渡梯度的变化，2)加速干扰对牧草和马尾草功能特性的影响，3)加速干扰对牧草和马尾草菌根定植的影响。通过更好地了解生态社区将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屏障岛屿的未来。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.