Noise- and delay-induced regime shifts in an ecological system of vegetation
Noise- and delay-induced regime shifts in an ecological system of vegetation
复制标题
植被生态系统中噪声和延迟引起的状态变化
DOI：
10.1088/1742-5468/2013/10/p10017
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发表时间：
2013-10
期刊：
影响因子：
--
通讯作者：
Jia, Zhenglin
中科院分区：
文献类型：
--
作者：
Han, Qinglin;Yang, Tao;Wang, Hua;Jia, Zhenglin
本文研究了具有时滞的植被模型中的平稳概率分布（SPD）和平均首次穿越时间（MFPT），其中植被动力学被假定为同时受到内在和外在噪声的干扰。分别讨论了内噪声强度α、外噪声强度D、时间延迟τ和两噪声间的互相关强度q对持续植被状态和贫瘠状态之间状态转换的SPD和MFPT的影响。我们的主要结果如下。(i)α的增加将导致从贫瘠状态到可持续植被状态的状态转变，而D或τ的增加将导致从可持续植被状态到贫瘠状态的状态转变。(ii)作为噪声强度的函数的MFPT（即，当q < 0.0时，α和D）出现一个最大值，最大MFPT表现出噪声增强可持续植被生物量稳定性的特征。(iii)然而，对于q <0.0？>的情况，，α或D的增加导致MFPT的降低，即，噪声可以增加区态向贫瘠状态转变的概率。(iv)虽然两个噪声之间的互相关是正的（q > 0.0），时间延迟的存在也会导致外部噪声增强稳定性的存在。
In this paper, the stationary probability distribution (SPD) and mean first passage time (MFPT) in a vegetation model with time delay are investigated, where the vegetation dynamics is assumed to be disturbed by both intrinsic and extrinsic noises. The impacts of the intrinsic noise strength α, extrinsic noise strength D, time delay τ and cross-correlation strength q between two noises on the SPD and MFPT of the regime shifts between the sustainable vegetation and barren states are discussed, respectively. Our main results are as follows. (i) The increase of α will cause regime shifts from the barren state to the sustainable vegetation state, while the increase of D or τ will cause regime shifts from the sustainable vegetation state to the barren state. (ii) The MFPT as a function of the noise intensities (i.e., α and D) exhibits one maximum value in the case of q < 0.0, and the maximum MFPT shows the characteristic of the noise enhanced stability of the sustainable vegetation biomass. (iii) However, for the case of q ⩾ 0.0?> , the increase of α or D causes a decrease of the MFPT, i.e., the noises can enhance the probability of regime shifts to the barren state. (iv) Although the cross-correlation between two noises is positive (q > 0.0), the presence of time delay can also cause the existence of extrinsic noise enhanced stability.
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影响因子：
3.7
作者：
Zheng XD;Yang XQ;Tao Y
通讯作者：
Tao Y
影响因子：
2.4
作者：
Frank, TD
通讯作者：
Frank, TD
影响因子：
2.9
作者：
C. Zeng;Hua Wang;L. Nie
通讯作者：
C. Zeng;Hua Wang;L. Nie
影响因子：
8.6
作者：
C. Broeck;J. Parrondo;R. Toral
通讯作者：
C. Broeck;J. Parrondo;R. Toral
DOI：
10.1103/physreve.80.041110
发表时间：
2009-08
期刊：
Physical review. E, Statistical, nonlinear, and soft matter physics
影响因子：
--
作者：
A. Fiasconaro;B. Spagnolo
通讯作者：
A. Fiasconaro;B. Spagnolo