Doctoral Dissertation Research: A Multi-Scale Analysis of Disturbance Dynamics in Hardwood Forest Communities on the Cumberland Plateau, USA

采用植物区系调查和树枝生态学方法，对坎伯兰高原次生混交阔叶林群落的天然林干扰事件进行调查。这些信息将提供关于小规模自然干扰事件在影响混合阔叶林的个体、种群、群落和生态系统层面的组成、结构和功能方面的作用的见解。在美国东部，大多数林隙尺度的干扰研究都集中在旧生长残留物上。由于19世纪和20世纪的自然和人为影响，美国东部的大多数林地都是二次生长的混合阔叶林。老生长残留林和成熟次生林的森林干扰动态可能有所不同。干扰特征和森林响应的差异归因于生物多样性、生物量安排和树龄分布的差异。这项研究将在坎伯兰高原进行，坎伯兰高原已被列为西半球最多样化和最濒危的生态区之一。不幸的是，缺乏关于坎伯兰高原森林资源和进程的信息。当前的野生动物栖息地、土地管理、保护和恢复工作需要有关坎伯兰高原生态系统的定量生态信息。这项研究将首次专门研究坎伯兰高原次生混交阔叶林中自然林隙尺度干扰的时空格局以及森林对这些干扰的响应。研究人员将(1)量化次生阔叶林群落的物种组成和林分结构，(2)记录干扰历史和气候对这些群落树木径向生长的影响，(3)量化林隙尺度干扰的时空格局和不同树种在这些次生林中的响应，以确定这些事件对坎伯兰高原阔叶林混交林物种组成和结构的影响。了解林分历史和干扰生态对于合理管理森林资源是重要的。该项目将量化自然干扰动态和干扰对坎伯兰高原物种多样性的影响，以帮助该地区目前的保护工作。该项目的成果将与地方、私人、州和联邦管理和保护组织共享。树木年轮数据将被贡献给国际树木年轮数据库，并将增加美国东部存在数据缺口的阔叶树物种急需的信息。这项研究的结果将在多个学科的多个专业会议上公布，并将被实施到田纳西州和阿拉巴马州幼儿园到12年级学生的外展计划中。

Floristic inventory and dendroecological methods will be used to investigate natural forest disturbance events in secondary mixed hardwood communities on the Cumberland Plateau. This information will provide insights on the role of small-scale natural disturbance events in shaping composition, structure, and function at the individual, population, community, and ecosystem level in mixed hardwood forests. The majority of gap-scale disturbance studies in the eastern United States have focused on old-growth remnants. Due to natural and anthropogenic influences during the 19th and 20th centuries, most forested lands in the eastern United States are comprised of second-growth, mixed hardwood stands. Forest disturbance dynamics likely differ between old-growth remnants and mature second-growth stands. Differences in disturbance characteristics and forest response are attributed to variations in biological diversity, biomass arrangement, and tree-age distribution. The study will be conducted on the Cumberland Plateau, which has been listed as one of the most diverse and endangered ecoregions in the western hemisphere. Unfortunately, information on forest resources and processes on the Cumberland Plateau is lacking. Quantitative ecological information about Cumberland Plateau ecosystems is needed for current wildlife habitat, land management, conservation, and restoration efforts. This research will be the first to specifically address the spatio-temporal patterns of natural gap-scale disturbances and the forest response to these disturbances in secondary mixed hardwood forests on the Cumberland Plateau. The researchers will (1) quantify species composition and stand structure in secondary mixed hardwood forest communities, (2) document the disturbance history and climatic influences on radial growth of trees these communities, and (3) quantify spatio-temporal patterns of gap-scale disturbances and the response of different tree species in these second-growth stands to determine the influence of these events on species composition and structure in mixed hardwood forest stands on the Cumberland Plateau.Knowledge of stand history and disturbance ecology is important for the proper management of forest resources. This project will quantify natural disturbance dynamics and the influence of disturbance on species diversity on the Cumberland Plateau to aid in current conservation efforts in the region. The results from this project will be shared with local, private, state, and federal management and conservation organizations. Tree-ring data will be contributed to the International Tree-Ring Data Bank and will add much needed information from hardwood tree species in the eastern United States where a data gap exists. The findings of this research will be presented at a number of professional meetings in multiple disciplines and will also be implemented into outreach programs for kindergarten through12th grade students in Tennessee and Alabama.