Doctoral Dissertation Research: Factors Affecting Forest Development and Stand Dynamics in Oak Forests in the Eastern U.S.

博士论文研究：影响美国东部橡树林森林发展和林分动态的因素

• 批准号: 1434260
• 负责人: Kurt Kipfmueller
• 金额: $ 1.6万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1434260&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Factors; Affecting

This doctoral dissertation research project will examine the factors contributing to the observed decline in oak (Quercus) species regeneration across the deciduous forests of the eastern United States. Using a variety of field-based and analytical methods, this project will investigate the multiple factors that may be contributing to decline rates in oak regeneration, including disturbance regime modifications, climatic change, land-use history legacies, and abiotic environmental conditions. Project results will provide much-needed insights into the complex dynamics occurring in oak forests across the eastern U.S., and they will increase theoretical knowledge regarding the ecosystem effects of land-use legacies and multiple, interacting forest drivers, such as canopy disturbances and drought events. Because oak forests offer important ecological, economic, and social benefits to society by producing food and habitat for wildlife, supporting associated vegetative communities, providing valuable timber, and offering scenic opportunities for recreation, this project will assist in the conservation of these benefits by providing information and insights regarding the mechanisms that are reducing the range of oak-dominated forests. The project also should suggest possible forest-management plans to prevent the loss of this important genus. The project will offer special education and training opportunities for undergraduate students who will assist with both field data collection and laboratory analysis. Results from this project will be disseminated broadly through scholarly publications and presentations and through educational outreach activities at land-management offices in the study area. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.Having dominated eastern deciduous forests for the past 5,000 years, the ecological, commercial, and societal importance of oak forests represents a distinctive long-term legacy across the eastern U.S., but oak species throughout the region are failing to regenerate due to the increased abundance of understory shade-tolerant species that prohibit light from reaching oak seedlings and saplings on the forest floor. The goal of this project is to elucidate the relative importance and the site-specific nature of the multiple forest drivers and to identify interactions among different drivers. The doctoral student will use forest-inventory, dendrochronological, and land-survey analysis methods to investigate multiple drivers of this compositional shift across the Driftless Area in southwestern Wisconsin, an area undergoing significant decreases in oak regeneration. She will examine land surveys from the 1840s and 1940s alongside modern forest inventory data to identify the forest development trajectories occurring throughout the study area. She will employ dendroecological methods to document canopy disturbance histories and to quantify the relationship between climate and radial tree growth. She will use structural equation modeling to analyze the relative influence of land-use legacies, canopy-disturbance history, climate, and site-specific abiotic factors on oak regeneration.

该博士学位论文研究项目将研究导致在美国东部落叶林中观察到的橡木（Quercus）物种再生下降的因素。 该项目使用多种基于现场和分析的方法，将调查可能导致橡木再生率下降的多种因素，包括干扰制度修改，气候变化，土地使用历史遗产和非生物环境条件。 项目结果将提供急需的见解，以了解美国东部橡木森林中发生的复杂动态，它们将增加有关土地使用遗产和多个相互作用的森林驱动因素的生态系统影响的理论知识，例如顶篷干扰和干旱事件。 因为橡树森林通过为野生动植物生产粮食和栖息地，为社会提供重要的生态，经济和社会利益，支持相关的营养社区，提供宝贵的木材，并为娱乐活动提供风景秀丽的机会，因此该项目将通过减少Oak占地森林范围的机制来帮助保护这些收益。 该项目还应提出可能的森林管理计划，以防止损失这一重要属。 该项目将为本科生提供特殊教育和培训机会，他们将协助实地数据收集和实验室分析。该项目的结果将通过学术出版物和演讲以及研究领域的土地管理办公室的教育外展活动进行广泛传播。 作为博士学位论文研究改进奖，该奖项还将提供支持，使有前途的学生能够建立强大的独立研究职业。在过去的5，000年中，占主导地位的东部森林占主导地位，橡树森林的生态，商业和社会重要性代表了整个美国东部地区的独特长期遗产，但在整个地区，oak又在整个地区进行了逐步抗衡，以至于对各地的各地进行了对等级的影响。禁止光在森林地面到达橡木幼苗和树苗。 该项目的目的是阐明多个森林驱动因素的相对重要性和特定地点性质，并确定不同驱动因素之间的相互作用。博士生将使用森林森林，树突学和土地调查分析方法来调查威斯康星州西南部无漂移区域的这种组成转变的多个驱动因素，这一区域正在大幅下降。她将与现代森林库存数据一起研究1840年代和1940年代的土地调查，以确定整个研究领域中发生的森林发展轨迹。 她将采用树状生态学方法来记录冠层干扰历史，并量化气候和径向树生长之间的关系。 她将使用结构方程建模来分析土地使用遗产，冠层干扰历史，气候和特定地点的非生物因素对橡木再生的相对影响。