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.

国家科学基金会摘要BCS-0964138、BCS-0964043Lisa M. Kennedy、Kam-biu Liu弗吉尼亚理工大学、路易斯安那州立大学关于飓风生态影响的文献很多，但几乎所有研究都集中在相对短期（数年）的变化。许多这些研究提出的一个持续存在的问题是，飓风是否会在长期（几十年到几个世纪）内改变森林组成。此外，人们假设美国东南部的亚热带海洋森林在飓风后火灾危险增加，但这种关系是否适用于热带森林仍然是一个问号。最近的进展允许在沉积物剖面中识别飓风登陆的代理记录，这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进行古生态分析，研究飓风对热带森林的长期（数十年至数百年）影响，以及飓风与火灾之间可能存在的联系。研究人员将分析沉积物中包含的地质、地球化学和生物指标，并使用放射性碳测年法来识别飓风登陆的记录，并研究这些登陆如何影响植被组成以及在长期范围内与火灾的相互作用。这项研究的一个关键目标是通过对花粉粒和微观结构的研究，记录飓风后植被变化是否长期持续，以及飓风袭击后热带生态系统的火灾危险是否增加（即飓风与火灾相互作用的假设）。飓风过度冲刷沉积物上方和下方间隔紧密的样本中存在木炭。飓风登陆频率相对较高的多米尼加共和国的多个研究地点将可以比较飓风对热带干燥和潮湿森林生态系统中植被和火灾的影响。对现代花粉雨和湖泊沉积物中历史飓风袭击特征的研究将为通过沉积代理数据解释古环境变化和事件提供基础。与中高纬度地区相比，热带地区的气候和植被动态知之甚少。地区。该项目将生成多米尼加共和国古飓风活动的代理记录，多米尼加共和国是加勒比地区的一个战略地点，用于评估影响千年时间尺度飓风活动的机制。这项研究的结果将揭示气候和环境历史的其他方面，包括可能包括前哥伦布时期的人类活动，并将有助于更广泛地了解加勒比地区的环境变化，因为该地区的长期历史记录仍然很少。这项研究将提供长期视角，并首次对多米尼加共和国的飓风重现期和登陆概率进行基于代理的估计，这可能对决策者在灾害规划和管理方面有用。该项目将为研究生和本科生提供参与现场和实验室国际研究的机会。