气候变化正在改变生态系统,影响生态系统的产品和服务。沿着墨西哥湾和美国东南部的大西洋海岸,极端冰冻事件的频率和强度极大地影响了沿海湿地是由对冰冻敏感的木本植物(红树林)还是耐冻的草样植物(盐沼)主导。为了应对变暖的冬天,在佛罗里达州北部的部分地区,红树林一直在以不同程度的严重程度扩大和取代盐沼,路易斯安那州,和德克萨斯州。随着冬季变暖的加速,红树林范围的扩大有望日益改变湿地生态系统的结构和功能。因为盐沼和红树林提供的生态和社会效益存在差异,沿海环境管理者面临的挑战是预测红树林扩张对关键湿地生态系统服务的影响,包括那些与碳封存有关的,野生动物栖息地,风暴防护,减少侵蚀,净水,渔业支持,和娱乐。面对极端气候事件和海平面上升,红树林范围的扩大也可能影响湿地的稳定性。这里,我们回顾了当前对红树林范围扩大和盐沼置换对美国东南部湿地生态系统服务的影响的理解。我们还确定了通过扩大红树林来解决盐沼流离失所对生态和社会影响的关键知识差距和新兴研究需求。在我们的整个审查中,一个一致的主题是,沿海管理人员需要考虑生态权衡。红树林的扩张和沼泽的位移可以在某些生态系统服务中产生有益的变化,同时对其他服务产生有害的变化。因此,对红树林向盐沼扩张的影响的看法可能存在局部尺度的差异。由于当地的特殊原因,有些人可能认为红树林的扩张是一个积极的变化,而其他人可能认为红树林的扩张是一种负面的变化,要受到限制。
Climate change is transforming ecosystems and affecting ecosystem goods and services. Along the Gulf of Mexico and Atlantic coasts of the southeastern United States, the frequency and intensity of extreme freeze events greatly influence whether coastal wetlands are dominated by freeze-sensitive woody plants (mangrove forests) or freeze-tolerant grass-like plants (salt marshes). In response to warming winters, mangroves have been expanding and displacing salt marshes at varying degrees of severity in parts of north Florida, Louisiana, and Texas. As winter warming accelerates, mangrove range expansion is expected to increasingly modify wetland ecosystem structure and function. Because there are differences in the ecological and societal benefits that salt marshes and mangroves provide, coastal environmental managers are challenged to anticipate the effects of mangrove expansion on critical wetland ecosystem services, including those related to carbon sequestration, wildlife habitat, storm protection, erosion reduction, water purification, fisheries support, and recreation. Mangrove range expansion may also affect wetland stability in the face of extreme climatic events and rising sea levels. Here, we review the current understanding of the effects of mangrove range expansion and displacement of salt marshes on wetland ecosystem services in the southeastern United States. We also identify critical knowledge gaps and emerging research needs regarding the ecological and societal implications of salt marsh displacement by expanding mangrove forests. One consistent theme throughout our review is that there are ecological trade-offs for consideration by coastal managers. Mangrove expansion and marsh displacement can produce beneficial changes in some ecosystem services, while simultaneously producing detrimental changes in other services. Thus, there can be local-scale differences in perceptions of the impacts of mangrove expansion into salt marshes. For very specific local reasons, some individuals may see mangrove expansion as a positive change to be embraced, while others may see mangrove expansion as a negative change to be constrained.