Collaborative Research: Long-Term Dynamics and Resilience of Terrestrial Plant and Animal Communities in the Bahamas

巴哈马群岛被洪水淹没的石灰岩洞穴或“蓝洞”中保存极为完好的植物和动物化石，为过去五千年或更久的环境变化提供了无与伦比的证据。最近在阿巴科岛的蓝洞中发现了多种多样的植物、无脊椎动物和脊椎动物化石，揭示了一个独特的史前陆地生态系统，其中陆龟是顶级食草动物，鳄鱼是主要捕食者（而不是大陆上的哺乳动物）。该研究项目将审查阿巴科岛和伊柳塞拉岛的长期生态变化，以评估史前和当代植物和动物群落如何应对长期环境波动，包括大约1 000年前人类到来后的文化影响。这个项目的动机是两个广泛的，相关的研究问题。首先，在这个控制良好的岛屿研究环境中，气候变化与人类影响的相对影响是什么？这项研究如何为在其他地方的生态研究中区分这些原因提供方法论和解释性的见解？对长期环境变化进行协调的多学科重建将考虑巴哈马北部的陆地生态系统在面对气候波动时是否具有弹性，但在史前人类到来后是否经历了具有级联效应的深刻影响。木炭、花粉、孢子、植物大化石和动物化石的年代记录将表明人类到达之前和之后的生物变化速度。第二个激励问题是：现代土地利用对陆地生物群落的影响是什么？将对现有动植物群落的组成和分布进行评估，因为它们反映了作为史前和历史土地利用遗产而改变的复原力。对阿巴科岛和伊柳塞拉岛生态变化的长期轨迹的解释将有助于区分气候变化对巴哈马群岛生物的影响与气候变化和人类影响的结合，对区分全球其他地方的这些原因具有更大的意义。该项目将为预测巴哈马和其他岛屿生态系统对气候和与人类有关的扰动的反应提供基础。特别是，全球生物多样性丧失的评估和管理取决于对地方和区域地理尺度以及短期和长期时间框架的生态系统动态的更好理解。对巴哈马陆地生态系统的分析将提供对一系列干扰制度（包括极端气候事件、飓风、火灾和土地利用变化）导致的适应能力、生物多样性和生态系统功能变化的见解。通过巴哈马广泛的公共和私人合作网络，该项目将加强国际科学合作，并制定严格的正式和非正式科学教育计划，包括大学生实习、公共实地考察和讲座、公民科学家的参与以及教育小册子的编制。该项目还将产生一种以生物地理和生态历史及史前史为基础的保护规划和土地管理方法。

Extremely well-preserved plant and animal fossils from flooded limestone caves or "blue holes" in the Bahamas provide unparalleled evidence of environmental change over the past five or more millennia. A diverse assemblage of fossil plants, invertebrates, and vertebrates recovered recently from blue holes on the island of Abaco reveals a unique prehistoric terrestrial ecosystem with tortoises as the top herbivores and crocodiles as the dominant predators (rather than mammals, as on continents). This research project will examine long-term ecological change on the islands of Abaco and Eleuthera in order to assess how prehistoric and contemporary plant and animal communities responded to long-term environmental fluctuations, including cultural impacts following the arrival of humans about 1,000 years ago. This project is motivated by two broad, related sets of research questions. First, what were the relative influences of climatic changes vs. human influences in this well-controlled island research setting, and how does this study offer methodological and interpretive insights for distinguishing between these causes in ecological studies elsewhere? Coordinated, multidisciplinary reconstructions of long-term environmental change will consider whether terrestrial ecosystems in the northern Bahamas were resilient in the face of climatic fluctuations but experienced profound impacts with cascading effects following the prehistoric arrival of humans. Dated records of charcoal, pollen, spores, plant macrofossils, and animal fossils will indicate rates of biotic change both before and after human arrival. The second motivating question is: What are the impacts of modern land use on terrestrial biotic communities? The composition and distribution of existing plant and animal communities will be assessed, because they reflect altered resilience as a legacy of both prehistoric and historic land use. The interpretation of long-term trajectories of ecological change on Abaco and Eleuthera will facilitate the differentiation of the biotic effects of climate change vs. the combination of climate change and human impacts in the Bahamas, with larger implications for separating these causes elsewhere around the globe.This project will provide a basis for predicting the responses of Bahamian and other island ecosystems to climatic and human-related perturbations. In particular, the assessment and management of worldwide biodiversity loss depend on an improved understanding of the dynamics of ecosystems at local and regional geographical scales as well as short and long time frames. Analyses of Bahamian terrestrial ecosystems will provide insights into changing resilience, biodiversity, and ecosystem function resulting from a suite of disturbance regimes, including extreme climatic events, hurricanes, fire, and land-use change. Through a broad network of public and private collaboration in the Bahamas, this project will enhance international scientific collaboration and develop a rigorous program of formal and informal science education, including internships for university students, public field trips and lectures, participation by citizen scientists, and development of educational brochures. The project also will generate an approach to conservation planning and land management grounded in biogeographic and ecological history and prehistory.