Community dynamics of insular biotas in space and time

摘要: The various features determining species distributions remain enigmatic in ecology. This thesis deals with the spatial and temporal dynamics of land birds on islands Dahlak archipelago, Red Sea, mammals, reptiles among forest fragments archipelago-like east African coastal forest. bird richness archipelago depended area, isolation extent habitat. Similarly, was related to habitat diversity but importance each factor varied taxa as well generalists specialists. For example, area influenced most categories except specialist mammals reptiles, more important for specialists than generalists, only birds. In both study areas, similarity composition decreased increasing distances isolates suggesting that dispersal from source pools facilitate re-colonization. nested community structure, i.e. species−poor communities are a subset species−rich communities, distribution few habitats. Similarities patterns cooccurrence patterns, at levels, were mainly preferences corresponding habitats inter-island distances. Also, distributional suggest predator-prey interactions can be determinant of, least, prey. There no evidence competitive exclusion. structure remained fairly stable over period 35 years even this arid region. turnover broadly predictable pattern not always consistent other expectations structure. Taken together my results show mechanisms varying scales act distributions, influence may vary depending ability. case conservation, comprehensive strategies accounting these variations needed.