LTREB: Woody Seedling Dynamics in a Wet Tropical Forest: Mechanisms of Species Co-existence

LTREB：潮湿热带森林中的木本幼苗动态：物种共存的机制

• 批准号: 0743609
• 负责人: Richard Kobe
• 金额: $ 40.5万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0743609&HistoricalAwards=false
• 关键词: LTREB; Woody; Seedling; Dynamics; Wet

A major challenge in ecology is to understand what determines the number and relative abundance of plant species in natural communities. This challenge is especially daunting in wet tropical forests, which harbor the highest species diversity of any ecosystem in the world. The seedling phase of a plant's life cycle is especially sensitive to pathogens and to the availability of light, nutrients, and water. What happens during this critical stage impresses a signature on forest species composition, from the understory to the canopy. Trees can live for much longer than humans and the dynamics of forests play out over even longer time scales; therefore, long-term data collection is necessary to capture important events that would be missed by short-term studies (e.g., seed production may occur every 12 years for some species). This proposal will extend an ~8 year record of seedling surveys in five forest stands in Costa Rica, with the goal of developing forest models of critical aspects of forest regeneration (seedling production, dispersion, growth and mortality) in response to light, soil fertility, and natural enemies. A better understanding of the factors that govern the relative abundance of tree species will aid in predicting forest responses to human influences, including the deposition of nitrogen, sulfur, and other chemical pollutants from the atmosphere. Furthermore, in tropical areas, exotic tree species often are used for reforestation because the regeneration requirements of native species are not well known, a knowledge gap that this research will help remedy. As part of this project, K-6 students will be growing plants in Michigan to learn about ecological processes that operate in all terrestrial ecosystems (from agricultural fields to wet tropical forest). Research results, data, and on-line identification tools will be shared with the public and other scientists through a project website.

生态学的一个主要挑战是了解是什么决定了自然群落中植物物种的数量和相对丰度。这一挑战在潮湿的热带森林尤其令人生畏，因为热带森林拥有世界上任何生态系统中最高的物种多样性。植物生命周期的幼苗阶段对病原体和光、养分和水的可用性特别敏感。在这个关键阶段发生的事情给森林物种组成留下了深刻的印象，从林下到冠层。树木的寿命比人类长得多，森林的动态变化需要更长的时间尺度；因此，长期数据收集是必要的，以捕捉短期研究可能错过的重要事件（例如，某些物种可能每12年产生一次种子）。该提案将延长哥斯达黎加5个林分约8年的幼苗调查记录，目标是开发森林更新（幼苗生产、分散、生长和死亡）的关键方面的森林模型，以响应光照、土壤肥力和天敌。更好地了解支配树种相对丰度的因素将有助于预测森林对人类影响的反应，包括大气中氮、硫和其他化学污染物的沉积。此外，在热带地区，外来树种经常被用于重新造林，因为本地树种的再生需求并不为人所知，这项研究将有助于弥补这一知识差距。作为该项目的一部分，K-6学生将在密歇根州种植植物，以了解所有陆地生态系统（从农田到潮湿的热带森林）中运行的生态过程。研究成果、数据和在线识别工具将通过项目网站与公众和其他科学家共享。