Colonization processes in semi-arid Mediterranean old-fields

摘要: Semi-arid Mediterranean ecosystems undergo a slow process of secondary succession after disturbance which is dependent on rainfall. We tested the hypothesis that colonization abandoned lands in semi-arid SE Spain was slowed down by seed dispersal and species-specific responses to climatic variability. In field glasshouse experiments we analysed germination two main colonizer species, their appearance as seedlings, relationships with climate resulting population structure. Seed dominant legume Anthyllis cytisoides Retama sphaerocarpa, enhanced scarification, but triggered temperature rainfall, respectively. There no evidence allelopathic effects affecting field. Population structure reflected high inter-annual variability shrub establishment, related rainfall spite self-thinning other processes modeled current numbers. Colonization semi-arid, environments seems be primarily limited dispersal, also affected variability, produced temporally separated recruitment events.