EFFECTS OF SELECTIVE LOGGING AND SHIFTING CULTIVATION ON THE STRUCTURE AND DIVERSITY OF A TROPICAL EVERGREEN FOREST IN SOUTH-EASTERN MEXICO

In order to make recommendations on forest management, we compared the floristic composition, diversity and physiognomy of a tropical evergreen forest (TEF) vegetation regenerating after two types of past use, namely, selective cutting and shifting cultivation, in Agua Blanca State Park, Mexico. These common types of use caused different kinds of forest disturbances. Plant cover was sampled in 32 quadrats randomly distributed in four stands of logged forest and four stands of secondary vegetation on land previously used for agriculture. A total of 220 species were recorded in 156 genera and 78 families of vascular plants. There were marked differences in the floristic composition, diversity and physiognomy between types of vegetation regenerations. Woody cover, canopy height and canopy cover were significantly higher in the selectively logged TEF than in the secondary vegetation after shifting cultivation, but herbaceous plant cover was comparable between regeneration types. Dominant tree and shrub species were different between regeneration types. The short fallow period for the plots previously used for agriculture resulted in the absence of intermediate regeneration stages, thus, hindering the succession of stands towards floristic composition and structure similar to those of logged TEF. Some alternative types of landuses that could mitigate negative impacts on forest regeneration are also discussed.