Brachet S, Olivieri I, Godelle B, Klein E, Frascaria-Lacoste N, Gouyon PH
Laboratoire d'Evolution et Systematique, Universite Paris-Sud, Bat. 362, Orsay Cedex, 91405, France.
J Theor Biol. 1999 Jun 21;198(4):479-95. doi: 10.1006/jtbi.1999.0926.
Conditions of persistence or extinction of a metapopulation of a colonizing annual species are studied in a heterogeneous landscape, a mixture of two elementary landscapes. An elementary landscape is a landscape whose age-structure is described by only one transition matrix, giving the probability for a site to be disturbed, or to follow the process of succession. We first provide an analytical study of the range of dispersal rates that allow metapopulation persistence in an elementary landscape. Second, conditions for metapopulation persistence in a heterogeneous landscape are derived from results obtained in each elementary landscape. Three cases are distinguished. If the two ranges of dispersal rates defined in each elementary landscape overlap, the metapopulation persists in any mixture of the elementary landscapes. If these two dispersal rates ranges are non-overlapping, either the metapopulation goes extinct for some values of the proportion of the elementary landscapes, or two discontinuous ranges of dispersal rates allow the metapopulation persistence. The consequences of these results are discussed in terms of landscape management. In particular, it is shown that under some conditions, a rapid change in environment (from one elementary landscape to another one) might less often lead to metapopulation extinction than a slower change. Copyright 1999 Academic Press.
在由两种基本景观混合而成的异质景观中，研究了一年生殖民物种集合种群的持续存在或灭绝条件。基本景观是一种其年龄结构仅由一个转移矩阵描述的景观，该矩阵给出了一个地点被干扰或遵循演替过程的概率。我们首先对允许集合种群在基本景观中持续存在的扩散率范围进行了分析研究。其次，根据在每个基本景观中获得的结果，推导出异质景观中集合种群持续存在的条件。区分了三种情况。如果在每个基本景观中定义的两个扩散率范围重叠，集合种群将在基本景观的任何混合中持续存在。如果这两个扩散率范围不重叠，要么集合种群在基本景观比例的某些值时灭绝，要么两个不连续的扩散率范围允许集合种群持续存在。从景观管理的角度讨论了这些结果的影响。特别是，结果表明在某些条件下，环境的快速变化（从一种基本景观到另一种）可能比缓慢变化更少导致集合种群灭绝。版权所有1999年学术出版社。
