异质种群动态模型:破碎化景观动态模拟的新途径

景观破碎化导致物种以异质种群方式存活，使得基于异质种群动态模拟破碎化景观动态成为可能。异质种群动态模型的发展为景观动态模拟奠定了良好基础。根据空间处理方式的不同，异质种群模型可分为三大类，可不同程度地用于描述破碎化景观动态。(1)空间不确定异质种群模型，假定所有局域种群间均等互联，模型中不包含空间信息，仅能用于景观斑块动态描述；(2)空间确定异质种群模型，假设局域种群在二维空间上以规则格子形式排列，是一种准现实的空间处理方式，可用于景观动态的简单描述；(3)空间现实异质种群模型，包含了破碎化景观中局域种群的几何特征，可直接用于真实景观动态的模拟研究。空间现实的和基于个体的异质种群模型不但是未来异质种群模型发展的主流，也将成为未来破碎化景观动态研究的重要工具。为了更加准确完整地描述破碎化景观动态，不但应该综合运用已有的各种异质种群模型方法，更要引进新模型来刎画多物种、多变量、高维度、复杂连接的破碎化景观格局与过程。

Metapopulation dynamic models: A novel approach to fragmented landscape dynamics

Landscape fragmentation is a main cause of ecological and environmental degradations, which has many serious impacts on regional biodiversity. Restoring fragmented landscapes thus become a new challenge to regional biodiversity conservation. Species are normally survived as metapopulations in a fragmented landscape, hence the patch dynamics could be determined by the dynamics of the metapopulations inhabited, which makes it possible to model fragmented landscape dynamics based on metapopulation dynamics. On the other hand, metapopulation dynamic models are paying more and more attention to involve the spatial features of a fragmented landscape in modeling, which provided a concrete support to describing fragmented landscape dynamics in a metapopulation way. In terms of the difference on spatial consideration, metapopulation models can be classified into three categories, namely the Spatial Implicit Metapopulation models (SIM), the Spatial Explicit Metapopulation models (SEM), and the Spatial Realistic Metapopulation models (SRM), each type of the models has its specialty in modeling fragmented landscape dynamics. (1) The SIM models made the assumption that all the local populations are equally connected, but the spatial information is not included in the model, which greatly simplified the model analysis. The SIM models, such as Levins models, 2 population Metapopulation models, and Structured Metapopulation models, can be used to describe the single patch dynamics in a fragmented landscape. (2) The SEM models are semi realistic, which assumed that local populations are consisted of the cells distributed regularly in the grids or on the lattices in a 2 deminsion space. It included Cellular Automata models, Interacting Particle Systems, Coupled Map Lattice models, and Reaction Diffusion Metapopulation model. These models can be employed to describe the fragmented landscape dynamics approximately. (3) The SRM models allowed one to include all the geometric information of a fragmented landscape into modeling. The three types of SRM models, Incidence Function Models, State Transition Models and n Population Simulation Models, are the suitable tools for modeling a real fragmented landscape. We should not only reinforce the SRM type and the Individual Based Metapopulation models while applying all the other metapopulation models in the future modeling of fragmented landscape dynamics, but also should find some new tools to describe the complex structures and processes of a fragmented landscape with multiple species, multiple dimensions, multiple variables, and complicated connections.