权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Mathematical study on global dynamics in ecological systems

生态系统全局动力学的数学研究

基本信息

批准号：
07304079
负责人：
SHIGESADA Nanako
金额：
$ 0.7万
依托单位：
Nara Women's University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07304079/
关键词：
mathematical model global dynamics disturbance biological invasion range expansion habitat fragmentation global change global warming グローハル動態生息地の網分化 species diversity gap dynamics lattice model indirect effect ecological inter

项目摘要

This study has aimed at theoretical understanding of global spatial and temporal changes in ecological systems with reference to various aspects of environmental issues. Specific subjects include conservation of diversity of ecosystems, invasion of alien species, extinction of rare species, function of ecosystems and so on. Representative results are summarized below.1. A mathematical model for invasions of two competing species into open spaces is investigated. The effect of disturbances that cause the environment to change in both time and space is examined, and principles of coexistence between the invading and native species are explored.2. Global diversification of termites driven by the evolution of sociality and symbiosis is discussed by means of the possible mechanism of C-N balance.3. Gap formation process in forested ecosystems is analyzed by using a lattice-structured forest model. A pair approximation technique is applied to predict the dynamics of gap formation, gap expansion, regeneration, and gap closure.4. By using data on the age-specific annual fecundity and catches-at-age by each fishery in a cub mackerel population in the Pacific Ocean off Japan during 1970-1992, the long-term fluctuation in impacts of two types of fisheries, the purse-seine fishery and the dip-net fishery, is evaluated.5. Invasion process is analyzed by using a stratified diffusion model, in which both the short and long range dispersals are taken into account. Applying models to the invasion of the House Finch, the effects of long- and short- distance dispersals on the range expansion are evaluated separately.

这项研究的目的是从理论上理解全球生态系统的时空变化，参考环境问题的各个方面。具体主题包括生态系统多样性保护、外来物种入侵、稀有物种灭绝、生态系统功能等。有代表性的成果总结如下1.研究了两个相互竞争的物种入侵开阔空间的数学模型。研究了引起环境在时间和空间上变化的干扰的影响，并探索了入侵物种和本地物种共存的原则。从C-N平衡的可能机制出发，探讨了社会性和共生性的演化驱动下的全球白蚁多样性。利用格子结构森林模型分析了森林生态系统中林隙的形成过程。应用对近似技术预测了空隙形成、空隙扩展、空隙再生和空隙闭合的动力学过程。通过使用1970-1992年日本附近太平洋的一个幼鱼种群中每个渔场特定年龄的年繁殖力和渔获量的数据，评估了两种渔业--围网渔业和斜网渔业--影响的长期波动。采用分层扩散模型对入侵过程进行了分析，该模型同时考虑了近距离扩散和远程扩散。将模型应用于家雀的入侵，分别评估了长距离和短距离扩散对范围扩展的影响。