Structure and causes of vegetation change in state and transition model applications

摘要: State and transition (ST) descriptions of rangeland vegetation dynamics provide information on current perceptions explicit causes change in dominant vegetation. Structural attributes ST applications allow an evaluation the complexity model comparisons with organization traditional succession-retrogression secondary succession. An analysis 29 revealed consistent trends. The number transitions connecting states showed a less-than-expected increase size application. This is probably associated limitations to interpret complex relationships need produce relatively simple applications. Larger exhibited shift towards stable pivotal positions within structures less connected (ie., fewer transitions) than expected by chance for given states. Thus, some assume key intermediary roles as considered increases. It debatable whether this property larger systems or effect modeling bias. confirmed about importance man-related sources disturbance. Grazing, fire, control woody plant species are visualized most relevant agents change. Some retain autogenic behaviors embedded spite event-driven nature approach. However, removes processes from their central role general approach theoretically very limited because no properties components (e.g., assemblages, individual species) growth, reproduction, mineralization) system used any comprehensive way generate predictive rules wider local relevance. Alternative approaches suggested that would ecological generalizations across systems.