A Study On Community Dynamics Of Coniferous And Broadleaf Mixed Forests In Wuyishan

There were a lot of secondary mixed forests of coniferous and broadleaf trees in Wuyishan world heritage area. Coniferous and broadleaf mixed forest was a transition type from coniferous forest to evergreen broadleaved forest. Study on the present status and the succession trend of coniferous and broadleaf mixed forest might provide scientific bases for protection and management in the future. Based on important value, Raunkiaer life classification system, species richness, Shannon-Wiener diversity index, Pielou evenness index, Simpson dominance index, M.Godron method of stability measuring (improved by ZhengYuanrun) and Markov prediction method, the community dynamics characteristics of coniferous and broadleaf mixed forest in Wuyishan world heritage area were analyzed. The results were as follows:(1) 4 types of mixed forests of coniferous and broadleaf trees in Wuyishan world heritage area were studied. The 4 types were as follows: A community (Cunninghamia lanceolata+Pinus massoniana+Alniphyllum fortunei+Castanopsis lamontii); B community ( Schima superba, Altingia gracilipes+pinus massoniana); C community (mesophylls+pinus massoniana+schima superba), D community (Cunninghamia lanceolata+Alniphyllum fortunei). 1 200 m2 permanent sample plots were set up in each communities respectively to survey the dynamics characteristics once a year in the short term of 5 years.(2) Top five dominant species of tree layers of four communities were not distracted by other species or external factors in the 5 years, and they were in the dominant status with relatively stable process. Particularly, Cunninghamia lanceolata took absolute advantage in D community. In the succession process, species in the shrub layers competed each other fiercely, with higher species turnover rate and short life cycling period. The dorminant species in the shrub layers and their dorminant values changed constantly.. The species number in the interlayers and herb layers were fewer and showed obvious dorminant phenonemas.(3) Life forms of phanerophyte were dorminant in the 4 communities meaning that the communities were posited in the warm and moist subtropic area. The appearance structure feature of B community was similar with that of subtropical evergreen-broadleaved forest. In the succession process of 5 a, the life-form spectrum trends of 4 communities were constantly stability.(4) The species richness, diversity index, evenness index and dorminant index in tree layers of the 4 communities changed in little degrees. The indexes in the shrub layers, interlayers and herb layers changed disorderly and sharply. (5) The 4 communities were unstable measured with M. Godron method.(6) The transition matrixes of Markov model were constructed with the transition percentage of relative dominance of trees in the 4 communities and the dorminant percentage of trees in the short-term succession course were predicted. The results indicated that Markov model might be used to predicted the dynamics of trees in mixed forests of coniferous and broad-leaved trees. The dorminances of broadleaved trees increased gradually, and the dorminances of coniferous trees changed contrarily and the processes were slow. The 4 communities would slowly develope to the evergreen broad-leaved forest in the future.The tree layers were relatively stable, and the shurb layers, interlayers and herb layers changed unsteadily in the 5 year's succssesion dynamics of the 4 types of coniferous and broadleaf mixed forest trees in Wuyishan world heritage area. The dynamics prediction of tree layers showed that the 4 communities developed to evergreen broadleaved forests slowly, and the processes were controled by tree layers. The all results would provided information and bases for restoration and protection of the vegetations in Wuyishan world heritage area.