Biogeochemical Responses to Variations in Climate and Disturbance in Terrestrial Ecosystems

生物地球化学对气候变化和陆地生态系统干扰的响应

• 批准号: 1651722
• 负责人: Edward Rastetter
• 金额: $ 73.12万
• 依托单位: Marine Biological Laboratory
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1651722&HistoricalAwards=false
• 关键词: Biogeochemical; Responses; Variations; Climate; Disturbance

Unlike agricultural ecosystems that rely almost exclusively on an external supply of nutrients through fertilizer application, most natural, land-based ecosystems, like forests, prairies, and tundra, rely almost exclusively on internally recycled nutrients to support plant growth. In these natural ecosystems, the supplies of nutrients like nitrogen and phosphorus from weathering bedrock and deposition in rain and dust are so slow that less than 5% of the annual plant productivity can be met from these external sources. Instead, these ecosystems accumulate nutrients over thousands of years and reuse and recycle them via internal nutrient cycles. This almost exclusive dependence on internally recycled nutrients means that the response of these ecosystems to a changing environment or to disturbance has to rely on a redistribution of nutrients already in the ecosystem, at least for the first few decades. Over hundreds of years, these responses depend on the ability of the ecosystem to retain and recycle more nutrients. This project will compare and contrast various types of ecosystems, from grassland to forest, from tropical to arctic, and develop a general model to describe how these ecosystems accumulate nutrients over time and how their dependence on recycled nutrients affects their responses to a varying climate, elevated carbon dioxide, and disturbances like wildfire, biomass harvest, or storm damage. The study promises to make an important contribution to our understanding of general ecosystem function, which will be valuable to increase understanding of how ecosystems around the world are regulated, how they respond to climate and disturbance, and how they can be managed as a sink for carbon dioxide in the future. It will also increase understanding of how and why ecosystems differ in their stability, resilience to disturbance. Researchers also will develop a teaching module for use in undergraduate courses to allow students to explore nutrient regulation of ecosystems. The model and associated data will be available to researchers and educators on the web and will also serve to link both research and educational programs at the Marine Biological Laboratory. This project will support one full-time post-doctoral scholar and a masters-level research assistant. This project builds on a theory of resource optimization and element interactions within ecosystems as formulated in the Multiple Element Limitation model, which simulates the optimization of resource acquisition by vegetation and soil microbes, the synchronization of nutrient cycles within ecosystems, and the coupling of these nutrient cycles with energy, carbon, and water fluxes through ecosystems. Through synthesis of existing data and the implementation and analysis of a model of the interactions among carbon, nitrogen, phosphorus, and water in terrestrial ecosystems, this project will examine biogeochemical constraints on responses to climate and disturbance and the consequent effects on carbon sequestration and ecosystem nutrient capital. Resource optimization describes how plants and microbes regulate the acquisition of vital resources to both maintain their metabolic balance and maximize growth. It is through this optimization and the balanced interactions between plants and soil microbes that ecosystems can accumulate vital nutrients and recycle them internally, which in turn allows higher production and carbon sequestration than would otherwise be possible. By comparing and contrasting responses to climate and recovery from disturbance in several different types of terrestrial ecosystem, this project will further advance the theory of resource optimization and element interactions in ecosystems, assess the mechanisms by which tight within-ecosystem nutrient cycles are synchronized, and evaluate the potentials of carbon and nutrient sequestration or loss across the globe.

与农业生态系统不同，几乎完全依赖外部营养物质通过肥料供应，大多数天然的，陆基的生态系统（如森林，草原和苔原）几乎完全依赖于内部再生营养素来支持植物的生长。在这些天然生态系统中，雨水和灰尘中的氮和磷等营养物质的供应速度如此之慢，以至于从这些外部来源中可以满足年度植物生产力的不到5％。取而代之的是，这些生态系统在数千年的时间内积累了养分，并通过内部营养周期再利用并回收它们。这种对内部再生营养物质的几乎独家依赖性意味着，至少在最初的几十年中，这些生态系统对不断变化的环境或干扰的反应必须依赖于生态系统中养分的再分配。在数百年的时间里，这些反应取决于生态系统保留和回收更多营养的能力。该项目将比较和对比各种类型的生态系统，从草原到森林，从热带到北极，并开发一个通用模型，以描述这些生态系统如何随着时间的流逝积累养分，以及它们对再生营养的依赖如何影响他们对气候的反应，对气候变化，甲二氧化碳二氧化碳和危害较高的野生型，或者造成了野生型，或者造成了危害，或者造成了危害，或者损害了暴风雨，或者暴露于暴风雨。该研究有望为我们对一般生态系统功能的理解做出重要贡献，这对于提高对世界各地的生态系统的监管，如何应对气候和干扰以及如何将它们作为未来二氧化碳的沉没进行管理非常有价值。它还将增加对生态系统如何以及为什么在稳定性上有所不同的理解，对干扰的韧性。研究人员还将开发一个教学模块，用于在本科课程中使用，以允许学生探索生态系统的营养调节。该模型和相关数据将用于网络上的研究人员和教育工作者，还将有助于将海洋生物实验室的研究和教育计划联系起来。该项目将支持一位全日制博士后学者和硕士级研究助理。该项目基于在多元元素限制模型中提出的生态系统中资源优化和元素相互作用的理论，该模型模拟了通过植被和土壤微生物对资源获取的优化，生态系统中养分周期的同步，以及这些营养循环与这些养分循环与这些养分循环的结合，并通过碳和水的结合。通过综合现有数据以及对陆地生态系统中碳，氮，磷和水之间相互作用模型的实施和分析，该项目将研究对气候和气候疾病的反应以及对碳序列和生态系统的影响的生物地球化学约束。资源优化描述了植物和微生物如何调节重要资源的获取，以维持其代谢平衡并最大化生长。通过这种优化和植物和土壤微生物之间的平衡相互作用，生态系统可以积累重要的养分并内部回收它们，这反过来允许比其他可能的更高的生产和碳固执。通过比较和对比对气候和从几种不同类型的陆地生态系统中的干扰中恢复的反应，该项目将进一步推进生态系统中资源优化理论和元素相互作用的理论，评估生态系统内部营养周期紧密的机制，并同步，并评估跨碳和营养层次和全球层的潜力。

项目成果

An approach to modeling resource optimization for substitutable and interdependent resources

一种对可替代和相互依赖的资源进行资源优化建模的方法

• DOI: 10.1016/j.ecolmodel.2020.109033
• 发表时间: 2020
• 期刊: Ecological Modelling
• 影响因子: 3.1
• 作者: Rastetter, Edward B.;Kwiatkowski, Bonnie L.
• 通讯作者: Kwiatkowski, Bonnie L.

Ecosystem Recovery from Disturbance is Constrained by N Cycle Openness, Vegetation-Soil N Distribution, Form of N Losses, and the Balance Between Vegetation and Soil-Microbial Processes

生态系统从干扰中恢复受到氮循环开放度、植被-土壤氮分布、氮损失形式以及植被与土壤-微生物过程之间的平衡的制约

• DOI: 10.1007/s10021-020-00542-3
• 发表时间: 2020
• 期刊: Ecosystems
• 影响因子: 3.7
• 作者: Rastetter, Edward B.;Kling, George W.;Shaver, Gaius R.;Crump, Byron C.;Gough, Laura;Griffin, Kevin L.
• 通讯作者: Griffin, Kevin L.