Collaborative Research: Long-Term Dynamics of Caribbean Maritime Forest Ecosystems in the Context of Major Disturbance Events: The Role of Hurricanes and Fires

合作研究：重大扰动事件背景下加勒比海洋森林生态系统的长期动态：飓风和火灾的作用

• 批准号: 0964043
• 负责人: Kam-biu Liu
• 金额: $ 12.41万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0964043&HistoricalAwards=false
• 关键词: Collaborative; Research; Long; Term; Dynamics

NATIONAL SCIENCE FOUNDATIONABSTRACTBCS-0964138, BCS-0964043Lisa M. Kennedy, Kam-biu LiuVirginia Tech, Louisiana State UniversityThe body of literature on the ecological impacts of hurricanes is large, but nearly all the studies have focused on relatively short-term (years) changes. A persistent question arising from many of these studies is whether hurricanes change forest composition over the long term (decades to centuries). In addition, increased post-hurricane fire hazards have been hypothesized for the subtropical maritime forests of the southeastern U.S., but whether this relationship holds for tropical forests is still a question mark. Recent advances allowing identification of proxy records of hurricane landfalls in sediment profiles provide an opportunity to address such questions. This project will examine the long-term (decades to centuries) impacts of hurricanes on tropical forests and the possible link between hurricanes and fire through paleoecological analyses of sediment records from coastal lakes in the Dominican Republic. The investigators will analyze geological, geochemical, and biological proxies contained in the sediments, and use radiocarbon dating, to identify records of hurricane landfalls and to examine how these landfalls influence vegetation composition and interact with fire over long time scales. A key objective of this research is to document whether post-hurricane vegetation changes persist over the long term and whether fire hazards increase in tropical ecosystems after hurricane strikes (i.e., the hypothesis of hurricane-fire interactions) through the study of pollen grains and microscopic charcoal in closely spaced samples above and below hurricane overwash deposits. Multiple study sites in the Dominican Republic, where there are relatively high frequencies of hurricane landfalls, will allow comparisons between hurricane effects on vegetation and fire in tropical dry and moist forest ecosystems. The study of modern pollen rain and the signatures of historical hurricane strikes in lake sediments will provide a basis for interpreting paleoenvironmental changes and events from sedimentary proxy data.Climate and vegetation dynamics are poorly understood in tropical areas in comparison to mid- and high-latitude areas. This project will produce proxy records of paleohurricane activity from the Dominican Republic, a location in the Caribbean region strategic for evaluating mechanisms affecting hurricane activity on millennial timescales. The results of this study will shed light on other aspects of climate and environmental history, including possibly pre-Columbian human activities, and will help to provide a broader understanding of environmental change in the Caribbean, where long-term history is still poorly documented. This research will provide a long-term perspective and generate the first proxy-based estimates of hurricane return periods and landfall probabilities for the Dominican Republic, which may be useful to decision makers in terms of disaster planning and management. This project will provide opportunities for graduate and undergraduate students to participate in international research with field and laboratory components.

国家科学基金会ABSTRACTBCS-0964138，BCS-0964043LISA M. KENNENDY，KAM-BIU LIUVIRGINIA TECH，LOUISIANA State University the The Modical of Tracor of Modication of Modical of Mogogical of Hurricanes的生态影响很大，但几乎所有研究都集中在相对短期（年份）上。许多研究引起的一个持续的问题是，飓风在长期（数十年到几个世纪）中是否改变了森林的组成。此外，在美国东南部的亚热带海洋森林中假设了河畔河畔火灾后的火灾危害增加，但是这种关系是否存在热带森林仍然是一个问号。最近的进步，允许识别沉积物概况中飓风登陆的代理记录为解决此类问题提供了机会。该项目将通过对多米尼加共和国沿海湖泊的沉积物记录的古生态分析来研究飓风对热带森林的长期影响（数十年至几个世纪）的影响。研究人员将分析沉积物中包含的地质，地球化学和生物代理，并使用放射性碳约会，以识别飓风登陆的记录，并研究这些登陆如何影响植被组成并在长时间尺度上与火相互作用。这项研究的一个关键目的是记录长期的幽灵后植被的变化是否持续存在，以及在飓风罢工（即飓风相互作用的假说）中是否通过花粉粒粒料和微观木炭在上方和下方的微观木炭上进行研究，是否增加了热带生态系统的增加（即飓风相互作用的假设）。多米尼加共和国的多个研究地点，飓风登陆的频率相对较高，将允许在热带干燥和潮湿的森林生态系统中对飓风对植被的影响与火之间进行比较。对湖泊沉积物中现代花粉降雨的研究以及历史飓风袭击的签名将为解释古环境变化和沉积代理数据中的事件提供基础。与中期和高处境相比，在热带地区，人们对热带和植被动态的了解很差。该项目将产生多米尼加共和国的古尿活动活动的代理记录，多米尼加共和国是加勒比地区战略的地点，用于评估影响千禧年时间标准飓风活动的机制。这项研究的结果将阐明气候和环境史的其他方面，包括可能是哥伦比亚前的人类活动，并将有助于对加勒比海的环境变化有更广泛的了解，在这些环境变化中，长期历史仍然很少记录。这项研究将提供长期的观点，并为多米尼加共和国的飓风返回期和登陆概率的第一个基于代理的估计值，这对于决策者在灾难计划和管理方面可能很有用。该项目将为研究生和本科生提供与现场和实验室组件一起参与国际研究的机会。