Collaborative Research: Linking models to data to investigate patterns and process in savannas

协作研究：将模型与数据联系起来以研究稀树草原的模式和过程

• 批准号: 0950347
• 负责人: Brian Beckage
• 金额: $ 35.5万
• 依托单位: University of Vermont & State Agricultural College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0950347&HistoricalAwards=false
• 关键词: Collaborative; Research; Linking; models; data

Savannas are ecological communities comprised of scattered trees in a grassland matrix. The mechanisms leading to the coexistence of grasses and trees and the persistence of savanna communities over long time periods are unclear. Opposing ecological theories have predicted either equilibrium savanna communities that result from niche partitioning or non-equilibrium savannas that result from repeated disturbances such as fire. This project will consider an alternative model to explain the structure of savannas, in which stability results from feedbacks between fire disturbance and vegetation. It will test the hypothesis that flammable savanna plants result in more frequent or intense fires and that these fires, in turn, promote the growth and establishment of savanna vegetation. Such positive feedbacks between savanna vegetation and fire could maintain the density of trees between the extremes of treeless prairies and the closed canopy of forests. The project will further explore whether less frequent, periodic disturbances such as hurricanes could have interactive effects with fire that could initiate vegetation-fire feedbacks and rescue savannas from a forest state. The underlying assumptions and predictions of a disturbance-feedback model will be tested using empirical and experimental data collected from sites that have been studied for the past 30 years in southern Florida, southwestern Georgia, and eastern Louisiana, and that broadly represent pine savannas in the southeastern United States. Demographic and spatial patterns predicted by a disturbance-feedback model will be compared to field observations and experimental data to ascertain the validity of the model.This alternative model of savanna dynamics will contribute to a general understanding of the processes that structure savannas across a wide range of environments worldwide, and will facilitate predictions of savanna responses to disturbances such as climate warming and landscape fragmentation. Understanding savanna responses to perturbations is of broad significance as savannas comprise an eighth of the global land surface, provide essential ecological services, and are important reservoirs of biodiversity. Results from this project will also be broadly applicable to ecological restoration and management of ecosystems across the United States. This project will support a postdoctoral scholar and provide research training for graduate and undergraduate students, and Girl Scouts at a camp near the study site in Louisiana.

Savannas是由草原基质中散落的树木组成的生态群落。 导致草和树木共存的机制以及长期以来稀树草原社区的持久性尚不清楚。 相反的生态理论预测，萨凡纳群落的平衡是由小众分配而产生的，或者是由于反复的骚扰（例如火）而导致的非平衡稀树草原。 该项目将考虑一个替代模型来解释稀树草原的结构，在这种模型中，稳定性是由于火灾干扰和植被之间的反馈而产生的。 它将检验以下假设：易燃的稀树草原植物会导致更频繁或强烈的大火，而这些火灾反过来又促进了稀树草原植被的生长和建立。 稀树草原植被和火之间的这种积极反馈可以维持无树成为大草原极端和森林封闭树冠之间的树木密度。 该项目将进一步探讨较少频繁的周期性干扰（例如飓风）是否可以与火灾产生互动效果，从而引发植被反馈并从森林状态中救出Savannas。 将使用从过去30年中在佛罗里达州南部，乔治亚州西南部和路易斯安那州东部研究的地点收集的经验和实验数据来测试扰动反馈模型的基本假设和预测，这些数据将在美国东南部广泛代表了美国东南部的野菜。 将通过干扰反馈模型预测的人口统计学和空间模式将其与现场观察和实验数据进行比较，以确定模型的有效性。这种稀树草原动态的替代模型将有助于对全球各种环境中稀树草原结构的过程的一般理解，并促进对萨凡纳（Savanna）的预测，例如避难所响应，例如避难所的温暖和landscape and landscape and landscape appecape and landscape speecape and landscape appecape appepape appepape appepape appecape appepape speecape。 了解萨凡纳对扰动的反应具有广泛的意义，因为萨凡纳斯占全球陆地表面的八分之一，提供基本的生态服务，并且是生物多样性的重要储层。 该项目的结果也将广泛地适用于整个美国生态系统的生态恢复和管理。 该项目将支持博士后学者，并在路易斯安那州研究地点附近的一个营地为研究生和本科生提供研究培训。