XVI International Botanical Congess

The landscape in the Southern Yucatan Region (SYP) is rapidly changing as slash and burn agriculture (SBA) increases in area. We studied forest regeneration following SBA in the SYPR, to evaluate the age at which successional forest becomes undistinguishible from ma ture forest. We established thirty 500 m2 circular plots, ten in old growth mid statured forest (MSF), ten plots in old growth low statured forest (LSF), and the remaining ten plots in succesional forest plots of known age following slash and burn agriculture in MSF. In each plot we measured structural characteristics (i.e. density of trees, canopy height, etc.), and identified all trees 10 cm in the entire plot. We found that at mid-successional stages (c. 8-15 years following SBA) forest plots are structurally very similar to LSF, but differed in tree species composition. After 20-25 years from SBA, forest plots were had similar structure and species composition than old growth MSF.