Numerical investigation of spatial pattern in a vegetation model with feedback function
Numerical investigation of spatial pattern in a vegetation model with feedback function
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具有反馈功能的植被模型空间格局的数值研究
DOI：
10.1016/j.jtbi.2008.05.017
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发表时间：
2008-09-21
影响因子：
2
通讯作者：
Li, Bai-Lian
中科院分区：
文献类型：
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作者：
Liu, Quan-Xing;Jin, Zhen;Li, Bai-Lian
半干旱土地上的植被通常是由光秃秃的地面或多或少地隔开的单个物种的斑块。Klausmeier[1999。半干旱植被的规则和不规则模式。《科学》284(5421)，1826-1828]报道说，条纹状的植被可以沿着缓坡的轮廓生长。他提出了一个基于水资源竞争的植被条纹模型。本文的主要目的是研究根系吸水和水资源再分配过程中水分和生物量对非饱和土壤植被空间格局形成的正反馈效应。根据色散关系公式，讨论了波长、波速的变化，以及空间模式形成的条件。数值结果表明，树木对空间异质性格局形成的正反馈函数比草类更敏感，正反馈越强，植被带出现的参数区域越大，表明正反馈提高了半干旱区从绿色状态向荒漠状态转变的可能性。数值结果还表明，正反馈可以提高植被条纹的迁移速度。爱思唯尔有限公司2008年版权所有版权所有。
The vegetative cover in semi-arid lands typically occurs as patches of individual species more or less separated from one another by bare ground. Klausmeier [1999. Regular and irregular patterns in semiarid vegetation. Science 284 (5421), 1826-1828] reported that the vegetation striped patterns can grow lying along the contours of gentle slopes. He has proposed a model of vegetation stripes based on competition for water. In this paper, our main aim is to study the positive feedback effects between the water and biomass on the vegetation spatial pattern formation within a nonsaturated soil, which arises from the suction of water by the roots and processes of water resource redistribution. According to the dispersion relation formula, we discuss the changes of the wavelength, wave speed, as well as the conditions of the spatial pattern formation. Our numerical results show that trees are more sensitive than grasses to the positive feedback function to format the spatial heterogenous pattern, and the stronger positive feedback increases the parameters region where vegetation bands occur, which indicates that the positive feedback raises the possibility of shift from green to desert states in semi-arid areas for the long term. Our numerical results also show that the positive feedback can increase the migration velocity of the vegetation stripes. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.