Theoretical Frameworks for Ecological Dynamics Subject to Stoichiometric Constraints

受化学计量约束的生态动力学理论框架

• 批准号: 0077790
• 负责人: Yang Kuang
• 金额: $ 21.5万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0077790&HistoricalAwards=false
• 关键词: Theoretical; Frameworks; Ecological; Dynamics; Subject

Kuang0077790 All organisms are composed of multiple chemical elementssuch as carbon, nitrogen, and phosphorus. Recent research in thearea known as ecological stoichiometry has highlighted theecological importance of the relative abundance of chemicalconstituents, known to vary considerably among species and acrosstrophic levels. However, most theoeretical studies in ecologyhave until very recently ignored the sources and consequences ofthis chemical heterogeneity. The investigator and his colleaguesundertake theoretical investigations of ecological stoichiometry.They develop a relatively new theoretical framework forecological dynamics that explicitly incorporates stoichiometricconstraints. This base model involves a stoichiometriccounterpart of the familiar Rosenzweig-MacArthur equations inwhich the effective carrying capacity of the resource species andthe transfer efficiency of the consumer species are constrainedby stoichiometric principles. Introduction of stoichiometricconsiderations in these equations (here, akin to "food quality")allows for a rich array of ecologically realistic dynamics,including deterministic extinction of the consumer species whenresources are abundant but of poor quality. They expand thismodel in five different directions, to explore ecologicalrealities (i.e., complications) whose consideration has provedilluminating in other, non-stoichiometric settings. Specifically,they analyze the dynamics of 1) a multi-nutrient model; 2)trophically complex models in which multiple consumer speciesshare a resource; 3) time delays in nutrient recycling that are arealistic component of terrestrial ecosystems; 4) two patchmodels featuring habitat heterogeneity and dispersal of theconsumer; and 5) age structured models in which juvenile andadult consumers differ in their nutrient requirements. Theproject aims to provide an analytically rigorous foundation forburgeoning empirical research into ecological stoichiometry. All living things, including humans, are constructed ofapproximately the same set of basic building blocks, chemicalelements such as carbon (C), nitrogen (N), phosphorus (P), andseveral dozen more in smaller amounts. However, differentorganisms contain different proportions of these key elements intheir biomass and thus must extract these elements from theirenvironment to differing degrees. In many situations, theenvironment does not provide these key nutrient elements in theabundance and proportions that are optimal for organism growthand reproduction. Thus, the chemical environment of life may setlimits on the success of organisms in various situations. In thisproject the investigators use mathematical models to simulate theflow of multiple chemical elements in natural food webs to betterunderstand how the requirements of living things for multiplechemical elements establish key feedbacks between the living andnon-living world. This work is important for two reasons. First,it may provide a better fundamental understanding of how chemicalelements move through food webs. Second, improved fundamentalknowledge of how nutrients move in the environment and how tosimulate those movements with mathematical tools may help predictand manage natural and human-dominated ecosystems, includingthose affected by nutrient inputs from human activities (e.g. Nand P inputs from fertilizer, sewage) or by global change (e.g.effects of increased atmospheric carbon dioxide on C and nutrientflow in the environment).

Kuang0077790所有生物都由多种化学元素组成，例如碳，氮和磷。 在被称为生态化学计量学的Thearea的最新研究强调了化学生相对丰度的生态学重要性，而化学生的相对丰度在物种和跨性水平之间已有很大变化。 但是，直到最近忽略了这种化学异质性的来源和后果，大多数生态学的理论研究。 研究者及其同学对生态化学计量的理论研究。他们开发了一个相对较新的理论框架的预报动力学，该动力学明确地融合了化学计量符号。 该基本模型涉及熟悉的Rosenzweig-Macarthur方程的化学计量范围，其中资源物种的有效承载能力以及消费者物种的转移效率受到限制。 在这些方程式中引入化学计量刻度（在此类似于“食品质量”）可以实现一系列生态现实的动态，包括当回顾性丰富但质量较差时，包括消费物种的确定性灭绝。 他们以五个不同的方向扩展了这种模型，以探索在其他非杂色的环境中经过考虑的考虑因素（即并发症）。 具体而言，他们分析了1）多营养模型的动力学； 2）多个消费者专门的资源的思考模型； 3）营养回收的时间延迟，这是陆地生态系统的角度成分； 4）两个贴片模型，具有栖息地异质性和thecmasumer的散布；和5）年龄结构化模型，其中少年和阿达德消费者的营养需求有所不同。 该项目旨在为生态化学计量法提供分析严格的基础。 包括人类在内的所有生物都均与相同的基本构建基块建造，例如碳（C），氮（N），磷（P）和较小量的二十多岁。 然而，不同的生物在其生物量中包含这些关键元素的不同比例，因此必须从其环境中提取这些元素到不同程度。 在许多情况下，环境并未以质量和比例为生物生长和繁殖最佳的比例提供这些关键的养分元素。 因此，生命的化学环境可能会在各种情况下有机体的成功限制。 在此项目中，研究人员使用数学模型来模拟天然食品网中多个化学元素的趋势，以更好地理解生物对多计算元素的需求如何在生活和努力生活世界之间建立关键的反馈。 这项工作很重要，原因有两个。 首先，它可以更好地了解化学元素如何通过食物网的移动。 Second, improved fundamentalknowledge of how nutrients move in the environment and how tosimulate those movements with mathematical tools may help predictand manage natural and human-dominated ecosystems, includingthose affected by nutrient inputs from human activities (e.g. Nand P inputs from fertilizer, sewage) or by global change (e.g.effects of increased atmospheric carbon dioxide on C and nutrientflow in the environment).