STUDY ON VEGETATION AND ITSSUCCESSI ON ON LOUJIA HILL,WUCHANG,WUHAN Ⅱ.SECONDARY SUCCESSION OF VEGETATION

The succession of vegetation on L oujia Hill,located on the campus of Wuhan University (30°32'N,114°2 1'E),was studied with the aid of the data provided by the predecessor. As the mostimportantvegetation type on the Hill,the structure of the mixed Quercus chenii+ Pinus massoniana formation,had changed a lot since its firstsurvey in 195 6.Among the arbor layer,percentage of Quercus chenii nearly kept constant(from69.0 1% in195 6to67.4 6% in1996),while that of Pinus massoniama declined sharply from2 1.13% to5.15 %.The increase rates of plantheightand diameter at breast height of Quercus were greater than those of Pinus.Under the canopy,shrub and herb layers declined obviously.Some evergreen broadleafed trees such as Cyclobalanopsis glauca and Cinnamomum camphora had invaded the forest successfully. The vegetation of L uojia Hill changed from grassland and shrubs to mixed Pinus massoniana+ Quercus chenii formation and several formations of conifers after its overall afforestation in192 8.In1962 ～ 1964,there were 2 1formations of vegetation.From then on,the greatestchange of the vegetation type is the disappearance of subtropics bamboo forestvegetation type,wooden subtype of the cultivated vegetation,and marsh-aquatic vegetation.Squares of shrubs and grassland declined largely,while those of mixed woods and artificial conifer forests increased.The authors predict that the vegetation of this area would develop to mixed evergreen+ deciduous broadleaved forest,and finally to subtropics evergreen broad-leaved one,which would be the climax of climate region.