Floristic patterns in understoreys under different disturbance severities in seasonal forests

This study evaluated the floristic diversity in the understoreys of 10 seasonal central brazilian semideciduous tropical forests in different stages of disturbance and tested the hypothesis that increased disturbance severity in a community directly affected the floristic diversity of the understorey. we evaluated phytosociological parameters of species and families as well as the structure of each understorey. floristic similarity was assessed between understoreys. results show celastraceae,rubiaceae,myrtaceae,meliaceae and siparunaceae as the five most important families. the five most representative species were cheiloclinium cognatum,cordiera sessilis,siparuna guianensis,trichilia catigua and t. claussenii. the analyses showed greater floristic similarity between understoreys under the same disturbance severity. increase in density of rubiaceae and decrease of meliaceae with increasing disturbance was observed. density of some species has also been linked to the level of forest disturbance. evaluating the distribution patterns of understoreys may help in understanding of ecological processes and the responses of vegetation in the face of future disturbances. © forest research institute malaysia.