Weeds established just as readily in plots with Manihot esculenta (the principal crop plant of the region) present as in plots with M. esculenta removed. Repeated farm-plot weedings caused woody plants to decline in numbers and biomass and herbaceous plants to increase. Forbs and grasses dominated immediately following farm site abandonment, but by 1 yr these had begun to senesce and fast-growing successional woody species (particulary Vismia spp.) were common. Standing crop biomass at 1 yr was 773 g dry weight m-2. Several microhabitat types were present on abandoned farm sites. Grasses and forbs showed no microhabitat preference, whereas successional woody individuals had their best establishment near slash and under fruit trees.