Role of dispersal in the invasion of an exotic tree in an East African submontane forest

摘要: Early successional tree species typically attract numerous generalist frugivores, many of which serve as seed dispersers. This study evaluated whether several such dispersers facilitated the invasion an exotic, early species, Maesopsis eminii (Rhamnaceae), in submontane forests East Usambara Mountains, Tanzania. The primary and their dispersal effectiveness were determined through focal watches at eight trees. Only 3 13 frugivores that consumed fruits functioned (silvery-cheeked hornbill Ceratogymna brevis, Fischer's turaco Tauraco fischeri blue monkey Cercopithecus mitis). On average, hornbills dispersed > 26 times more seeds than monkeys, turacos per visit thus considered most important disperser. Seed germination was not affected by gut passage hornbills. Germination four microhabitats experimentally to determine microhabitat influences success. Large gaps forest edges had significantly higher rates compared with understorey locations; rate small different from understorey. Expansive Usambaras likely enhanced both rapidity scale presence extremely effective agent. silvery-cheeked hornbill.