ABSTRACT
Bryophyte habitats are patchy in time and space. The population dynamics of such systems operate at two levels, within-patches and between-patches. Simulation models are powerful tools to aid understanding of the dynamics and to make predictions about future development of populations. The models must, however, be built on the knowledge of both population and habitat parameters. The chapter discusses the use of metapopulation models and shows few examples where such simulation models may be useful to predict the outcome of, for example, environmental changes. Most population models assume that dispersal between habitat patches is important, but the effects of dispersal on habitat occupation may vary. Dispersal may be sufficiently efficient that the species essentially occupies every available habitat patch, i.e. its frequency at the landscape scale is determined by the number of available habitats. One of the obvious changes of the modern landscape is the fragmentation of many habitats that earlier covered vast areas, e.g. boreal forests.
