Doctoral Dissertation Research: Vegetation Dynamics of Endangered Pine Rockland Communities in the Lower Florida Keys

南佛罗里达湿地松（Pinus elliottii var. densa）是下佛罗里达礁岛群松树岩地的优势木本树种和唯一的树冠树种。 这些全球濒危的社区支持西印度硬木和棕榈树以及各种地方性草药的多样化亚树冠，这些草药交替地受到火的鼓励或抑制。 本博士论文研究计画将利用树木年代学来探讨下佛罗里达礁群衰退松树罗克兰群落的结构与干扰历史。 生态和气候因素有助于南佛罗里达湿地松在其范围的南部范围的分布将进行检查。 此外，重建过去的火灾制度的空间和时间的变化将提供一个更好地了解火灾如何影响这些社区的结构和范围。 该项目还将调查区域气候振荡（如厄尔尼诺-南方涛动）和野火活动之间的相互作用。 湿地松群落的历史火灾发生和气候响应的定量信息是必不可少的长期管理和恢复的松树罗克兰community.This项目将增加基本的了解，如何人为和自然干扰事件减少了南佛罗里达湿地松在下佛罗里达键的空间分布。 这个项目将在佛罗里达的最南部应用树木年代学技术，在一个亚热带地区，树？]环科学从未被应用，它将产生气候代用数据集，这将增加不断增长的全球低？纬度气候代用资料。 这项研究的结果将有助于了解气候振荡如何影响该地区，特别是南佛罗里达，他们将推进理解复杂的动态松树岩地，这将有助于管理工作，旨在保护这些下降的社区。 该项目产生的植被数据将提供关于林龄分布和与自然和人类有关的干扰制度有关的组成的宝贵信息，关于定居前野火与气候机制之间的关联的数据将更好地了解火灾如何塑造松树岩地以及气候振荡影响火灾发生的程度。 作为博士论文研究改进奖，该奖项将为博士生建立强大的独立研究生涯提供支持。

South Florida slash pine (Pinus elliottii var. densa) is the dominant woody species and sole canopy tree in pine rocklands of the Lower Florida Keys. These globally endangered communities support a diverse subcanopy of West Indian hardwoods and palms as well as a variety of endemic herbs that are alternately encouraged or held back by fire. This doctoral dissertation research project will use dendrochronology to investigate the structure and disturbance history of declining pine rockland communities in the Lower Florida Keys. The ecological and climatological factors contributing to the distribution of South Florida slash pine at the southern extent of its range will be examined. In addition, the reconstruction of spatial and temporal variability of past fire regimes will provide a better understanding of how fire affects the structure and extent of these communities. This project also will investigate the interaction between regional climate oscillations (e.g. the El Nino-Southern Oscillation) and wildfire activity. Quantitative information on the historical fire occurrence and climate response of slash pine communities is essential to the long-term management and restoration of pine rockland communities.This project will increase basic understanding of how human-related and natural disturbance events have decreased the spatial distribution of South Florida slash pine in the Lower Florida Keys. This project will apply techniques of dendrochronology in extreme southern Florida, in a subtropical region where tree?]ring science has never been applied, and it will produce climate proxy datasets that will add to the growing global network of low?]latitude climate proxy data. Results from this research will contribute to the understanding of how climate oscillations affect the region, particularly South Florida, and they will advance understanding of the complex dynamics of pine rocklands that will aid management efforts aimed at preserving these declining communities. The vegetation data produced by this project will provide valuable information regarding stand age distribution and composition in relation to natural and human-related disturbance regimes, and data on the association between pre-settlement wildfire and climate mechanisms will provide a better understanding of how fires shaped pine rocklands and the extent to which climate oscillations affected fire occurrence. As a Doctoral Dissertation Research Improvement award, this award will provide support for a doctoral student to establish a strong independent research career.