Secondary succession and indigenous management in semideciduous forest fallows of the Amazon basin

To the discussion on secondary succession in tropical forests, we bring data on three under-addressed issues: understory as well as overstory changes, continuous as opposed to phase changes, and integration of forest succession with indigenous fallow management and plant uses. Changes in vegetation structure and species composition were analyzed in secondary forests following swidden agriculture in a semideciduous forest of Bolivian lowlands. Twenty-eight fallows, stratified by four successional stages (early = 1¿5 yr, intermediate = 6¿10 yr, advanced = 12¿20 yr, and older = 22¿36 yr), and ten stands of mature forests were sampled. The overstory (plants ¿5 cm diameter at breast height [DBH]) was sampled using a 20 × 50 m plot and the understory (plant