Collaborative Research: Long-term Studies of Forest Dynamics: Analysis of Seedling and Sapling Populations

合作研究：森林动态的长期研究：幼苗和幼树种群分析

• 批准号: 9107357
• 负责人: Robert Peet
• 金额: $ 14.67万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-01 至 1994-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9107357&HistoricalAwards=false
• 关键词: Collaborative; Research; Long; term; Studies

Disturbance is nearly ubiquitous in ecological systems. Consequently, succession, the process of recovery from disturbance, is responsible for much variation in ecosystem structure and function. The primary objective of this research is to understand the process of succession, and the investigators assert that most successional changes in community-level properties and processes can best be understood as resulting from population processes. Although permanent plots are commonly used to examine the dynamics of mature trees, seedling and sapling dynamics remain virtually unstudied, simply because appropriate data have not been available. With the support of the National Science Foundation Long-term Research in Environmental Biology (LTREB) program, the investigators have collected seedling and sapling data from permanent plots in numerous types and ages of forests with observations ranging up to 13 years. Consequently the investigators are uniquely positioned to examine the dynamics of seedlings and saplings as related to succession and site characteristics. The LTREB dataset will be used to address questions related to the dynamics of seedlings and samplings such as the following: (1) How do seedling and sapling establishment, growth, and survival vary with succession and site conditions? (2) Is seedling-seedling competition significant? We suspect that competition with canopy trees controls seedling dynamics, except in canopy gaps, but if seedling interactions are important they will need to be added to forest simulation models. (3) Do canopy trees differentially inhibit conspecific seedlings and saplings? This is a popular hypothesis, largely untested in temperate forest. (4) Can year-to-year climatic variation explain co- existence of similar tree species? Again, this a popular but untested hypothesis. (5) Does seedling vigor change during succession in a fashion consistent with existing models of changing canopy-derived competition (see Peet and Christensen 1987)? This research will provide a unique perspective on successional patterns from a population standpoint.

干扰在生态系统中几乎无处不在。 因此，继承，恢复的过程， 干扰是生态系统中许多变化的原因 结构和功能。 这项研究的主要目的是 是了解继承的过程， 认为社区一级的大多数连续性变化 性质和过程可以最好地理解为 人口过程。 虽然永久性地块通常用于检查 成树动态、幼苗动态和幼树动态保持不变 几乎没有研究，只是因为适当的数据没有 一直可用。 在国家科学院的支持下， 环境生物学长期研究基金会 计划，调查人员已经收集了幼苗和树苗 许多类型和年龄的森林的永久样地的数据 观察时间长达13年。 从而 调查人员处于独特的地位，可以检查 与演替和立地有关的幼苗和幼树 特色 LTREB数据集将用于解决与 幼苗和取样的动态，如： (1)苗木和树苗如何建立，生长， 存活率随演替和立地条件而变化？ (2)是 实生苗竞争显著？ 我们怀疑 与树冠树木的竞争控制着幼苗动态，除了 在林冠间隙，但如果幼苗的相互作用是重要的， 将需要添加到森林模拟模型中。 (3)做天篷 树木差异抑制同种幼苗和幼树？ 这是一个流行的假设，在很大程度上未经检验的温带 森林 (4)气候的年变化能解释气候变化吗？ 有没有类似的树种？ 同样，这是一个受欢迎的，但 未经验证的假设 (5)幼苗活力在 以符合现有模式的方式继承 不断变化的树冠衍生竞争（参见Peet和Christensen （1987年）？ 这项研究将提供一个独特的视角， 从种群的角度来看，