Edge structure determines the magnitude of changes in microclimate and vegetation structure in tropical forest fragments.

摘要: Edge structure is one of the principal determinants extent and magnitude edge effects in forest fragments. In central Amazonia, natural succession at edges typically produces a dense wall vegetation dominated by Cecropia spp. that buffers interior. Fire encroachment into edges, however, eliminates soil seed bank, enhances plant mortality, promotes to an open, Vismia–dominated does not buffer Contrasting fire–encroached closed, non–fire–encroached were examined Amazonia assess on microclimate tropical penetration distances for most variables as much two five times greater open than closed edges. The these differences suggests main within fragments. Edge also varied systematically with fragment area. For given type, 100–ha fragments had consistently lower canopy height, higher foliage density, temperature, rate evaporative drying, leaf litter moisture content, depth continuous forest, all from edge. These differences, relatively minor compared striking between organisms small fragments, difference may be total hand effective nature reserve other, independent absolute