Abstract:

We analyzed the dynamics of species composition and diversity change of 〖WTBX〗Schima argentea〖WTBZ〗 forest in Jinyun Mountain during the natural succession for the last two and a half decades,1984 to 2009.The research showed that the number of species had decreased from 57 in 1984 to 39 in 2009 and plants in herbage and liana layer died out gradually.Meanwhile,the breast area of trees in canopy layer in which DBH was longer than 75 cm has fallen.Though the composition and diversity had changed,〖WTBX〗Schima argentea〖WTBZ〗 still dominated the forest.〖WTBX〗Neolitsea aurata〖WTBZ〗 var.〖WTBX〗glauca,Symplocos setchuanensis〖WTBZ〗 and 〖WTBX〗Rhododendron stamineum〖WTBZ〗 had become more and more from 1984 to 2009,but 〖WTBX〗Castanopsis carlesii〖WTBZ〗 var.〖WTBX〗spinulosa〖WTBZ〗 was on the contrary.The four αdiversity indices in this community were on the downtrend.Richness index had reduced from 298 in 1984 to 199 in 2009.ShannonWiener index had reduced by 034 in last 25 years while Simpson index and Pielou index remained almost the same.Besides,the analysis of βdiversity and Whittaker index which was 018 also showed that there was a large difference in the 〖WTBX〗Schima argentea〖WTBZ〗 community between 2009 and 1984.In conclusion,the remarkable difference between the two periods of time is of significance for the management of 〖WTBX〗Schima argentea〖WTBZ〗 forest in Jinyun Mountain and the subtropical evergreen broadleaved forest of upper reaches of the Yangtze River.〖