Habitat fragmentation and extinction thresholds in spatially explicit models
Habitat fragmentation and extinction thresholds in spatially explicit models
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DOI：
10.2307/5781
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发表时间：
1996-07-01
影响因子：
4.8
通讯作者：
Sole, RV
中科院分区：
文献类型：
--
作者：
Bascompte, J;Sole, RV
1.利用空间显式模型研究了栖息地破坏对单个集合种群生存的影响。随着破坏场地比例的增加，景观的结构属性呈现出非线性变化，表现出临界阈值和相变的存在。这种临界阈值是通过序参数来识别的，该序参数区分了定量过程(即生境损失)和定性过程(即生境碎片化)，这种差异只有在空间上明确的框架下才能很好地理解。在这样一个支离破碎的地貌上，我们通过元胞自动机形式化的方法介绍了通过局部殖民和灭绝来平衡集合种群的动态。据报道，当栖息地的某一部分被破坏时，存在灭绝阈值。这些阈值既由景观结构属性的临界行为决定，也由集合种群的人口属性决定。描述并解释了这些结果与空间隐式模型的研究结果之间的一些差异。特别是，在空间显式公式中，对于给定的栖息地破坏值，斑块占用百分比更低。消光阈值也发生在较低的破坏值。讨论了对自然景观管理的一些启示。
1. The incidence of habitat destruction on the survivorship of a single metapopulation is studied by means of a spatially explicit model.2. As the proportion of destroyed sites increases, the structural properties of the resulting landscape change in a non-linear way, showing the existence of critical thresholds and phase transitions.3. Such critical thresholds are identified by means of an order parameter, which discriminates a quantitative process, i.e. habitat loss, from a qualitative one, i.e. habitat fragmentation, This difference is only well understood using a spatially explicit framework.4. We introduce on such a fragmented landscape the dynamics of a metapopulation balanced by local colonization and extinction by means of the cellular automaton formalism.5. The existence of extinction thresholds when a given fraction of habitat is destroyed is reported. These thresholds are determined both by the critical behaviour of the landscape structural properties, and by the demographic properties of the metapopulation.6. Some differences between these results and those derived from the study of spatially implicit models are described and explained. In particular, the percentage of patch occupancy is lower for a given value of habitat destruction in the spatially explicit formulation. Extinction threshold also take place for a lower destruction value. Some implications for the management of natural landscapes are discussed.