随机干扰下多稳植被生态系统稳态转换的时间延迟效应研究

项目名称： 随机干扰下多稳植被生态系统稳态转换的时间延迟效应研究

项目编号： No.11305079

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 曾春华

作者单位： 昆明理工大学

项目金额： 22万元

中文摘要： 多稳态现象广泛存在于生态系统中，不同的稳态对应于不同的生态系统结构和功能，并且可产生不同的生态系统服务价值。具有多稳态的生态系统经常会发生不同稳态之间的转换，从而导致生态与经济方面的损失。本项目以植被生态退化过程中的不同稳态之间转换为研究对象，考虑外界环境随机干扰及系统退化过程中时间延迟效应，建立含有噪声和延迟的多稳植被生态系统模型。基于延迟Fokker-Planck方程及改进Euler数值模拟，计算表征多稳生态系统跃迁行为的特征参量(稳态概率分布和跃迁时间等)，分析噪声和延迟因素对该系统稳态转换预警指标(两个相反方向稳态跃迁时间的交点等)的影响机制，探讨多稳植被生态系统的稳定性和恢复力，揭示其稳态转变规律及植被生态恢复。本项目的实施在于以非平衡统计物理的方法来研究复杂的多稳植被生态系统，从物理学相变理论的角度理解多稳植被生态系统的稳态之间转换机制，为植被生态系统修复提供一定的参考。

中文关键词： 噪声；时间延迟；植被生态系统；稳态转换；预警信号

英文摘要： Multiple stable states widely exist in the ecosystem, different steady states correspond to different ecological structures and functions , and can exert different values of ecological services. The multistable ecosystem often shifts between different steady states.As a result,such regime shifts can lead to degradation of ecology and economy. The project utilizes shifts between different steady states in the process of vegetated ecological degradation as the research object, considers the external environmental perturbations and the effect of time delay in the process of system degradation , and establishes a multistable vegetated ecological model containing noise and delay. Based on the delayed Fokker-Planck equation and modified Euler numerical simulation,calculating characteristic parameters of the transition behavior in multistable ecosystems (steady state probability distribution and regime shift time, etc), analyzing the effect mechanism of noise and time delay factors on the warning indicators of regime shifts (including intersection point of regime shift time in two opposite directions,etc) of the ecosystem, exploring the stability and resilience of multistable vegetated ecosystem and revealing the laws of regime shift and vegetated ecological restoration , the implementation of this project depends

英文关键词： noise；time delay；vegetated ecosystems；regime shift；warning signal