Doctoral Dissertation Research: A Multi-Scale Analysis of Disturbance, Dynamics, and Climate-Growth Relationships in Mountain Longleaf Pine Forests, USA

博士论文研究：美国山地长叶松林的干扰、动态和气候-生长关系的多尺度分析

• 批准号: 0927687
• 负责人: Lisa Kennedy
• 金额: $ 0.83万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0927687&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Multi; Scale

This research integrates geospatial and ecological approaches to examine the roles of climate, competition, disturbance, and human activities in regulating the composition and structure of old-growth and second-growth mountain longleaf pine forests of the southeastern United States. Mountain longleaf pine forests are relatively understudied components of the imperiled and highly diverse longleaf pine ecosystems that historically dominated the Coastal Plains and parts of the Piedmont, Ridge and Valley, and Southwestern Appalachians. These mountain forests are at the northern latitudinal and altitudinal range margin for longleaf pine ecosystems. Doctoral student Arvind Bhuta, under the supervision of Dr. Lisa Kennedy at Virginia Tech will produce a high-resolution (temporal and spatial) reconstruction of competition and disturbance at multiple mountain longleaf pine sites. Randomly placed study plots in mountain longleaf pine forest sites will be surveyed for forest structure and composition. All canopy trees within the plots will be identified, measured, referenced with a global positioning system, and cored. Analysis of forest metrics in a geographic information system will document forest processes and patterns at multiple spatial scales ranging from individual tree species and communities to the broader ecosystem. Annual rings from each tree will be measured, standardized, and statistically analyzed. Tree rings provide an annual-resolution record of tree growth, forest composition and structure, and proxy records of climate, disturbance, and competition through time. Historical tree growth will be linked with current forest metrics, land-use history, and climate records to provide detailed information on long-term forest dynamics and the drivers of change in this ecosystem. The investigation of the relationship between climate and longleaf pine radial growth will allow for comparisons to be made between sites at the range margin and others throughout its range to better understand the geographic variation in the climate response of this species. Mountain longleaf pine forests are economically and biologically valuable. They are high in biodiversity and rich with endemic herbaceous and vertebrate species some of which are now rare and endangered due to intense land-use patterns, fragmentation, and the disruption of the natural fire regime. Long-term records of forest dynamics across multiple sites will provide context for sound decisions on the restoration and management of these forests and its vulnerable species, such as the red-cockaded woodpecker and the Cumberland azalea. This research will fill a critical gap in the knowledge of mountain longleaf pine forests by providing new information on the ecological drivers of ecosystem and community processes and patterns which could be influenced by climate change. Land managers of mountain longleaf pine forests have based management and restoration practices on studies that focused on individual stands and short time scales, many at lowland sites that may differ in ecological function. In contrast, this research will account for pattern and processes over large temporal and spatial scales.

这项研究结合了地理空间和生态方法，以检查气候，竞争，干扰和人类活动在调节美国东南部老年增长和第二增长山长松树林的组成和结构中的作用。 山叶松树林是相对研究的组成部分，这些成分是危险和高度多样化的长叶松树生态系统，历史上以沿海平原和皮埃蒙特，里奇和山谷以及西南阿巴拉契亚人的一部分占据主导地位。 这些山区森林位于长叶松树生态系统的北纬度和海拔范围。 博士生Arvind Bhuta，在弗吉尼亚理工大学Lisa Kennedy博士的监督下，将在多个山长叶松树遗址进行高分辨率（时间和空间）重建竞争和干扰。 将调查山叶松树林地中随机放置的研究地块，以进行森林结构和组成。 将识别，测量，用全球定位系统引用并核心地块中的所有树冠树。 地理信息系统中森林指标的分析将记录从单个树种和社区到更广泛的生态系统的多个空间量表的森林过程和模式。 将测量，标准化和统计分析的每棵树的年度环。 树环提供了树木生长，森林组成和结构的年分辨率记录，以及随着时间的推移的气候，干扰和竞争的代理记录。 历史树的增长将与当前的森林指标，土地利用历史和气候记录有关，以提供有关长期森林动态和本生态系统变化驱动因素的详细信息。 对气候与长叶松径向生长之间关系的研究将使在整个范围内的范围和其他位置之间进行比较，以更好地了解该物种气候反应的地理变化。山长松树森林在经济和生物学上都是有价值的。 它们的生物多样性很高，并且富含地方性草本和脊椎动物物种，其中一些物种由于强烈的土地利用模式，碎片化以及自然火力的破坏而罕见并濒临灭绝。 跨多个地点森林动态的长期记录将为这些森林及其脆弱物种的恢复和管理（例如红色锁定的啄木鸟和坎伯兰杜鹃花）提供正确的决定。 这项研究将通过提供有关生态系统和社区过程和模式的生态驱动因素的新信息，从而填补对山长叶松林的了解，这些信息可能会受到气候变化的影响。 山长松树森林的土地管理者对关注单个支架和短时间尺度的研究具有基于管理和恢复实践，许多在低地地点可能在生态功能上有所不同。 相比之下，这项研究将解释大型时间和空间尺度上的模式和过程。