混交对杉木和山杜英混交林生长、结构和生产力的影响OA北大核心CSTPCD

To explore the mixing effect of Cunninghamia lanceolata and Elaeocarpus sylvestris,20-year-old pure and mixed C.lanceolata and E.sylvestris plantations in Fengshushan Forestry Farm in Jingdezhen were selected as test objects,and three slope positions(up slope position,middle slope position and down slope position)were set for each stand type,and the effect of mixed tree species on the plantation growth was analyzed,and the responses of the mixed effects on site condition and on environmental factors was investigated,respectively.The results showed that the volume of the mixed forests ircreased by 5%compared with the expected volume,showing a slightl increase.Compared with pure stands,the diameter distributions of the two species showed opposite trends to the mixed,the peak of diameter distribution of C.lanceolata in mixed stands moved towards higher order,however,the peak of diameter distribution of E.sylvestris in mixed stands moved towards lower order.The allometric analysis of coarse root diameter-stem diameter of pure and mixed plantations showed that C.lanceolata allometry in mixed forests was focused on stem growth,while E.sylvestris allometry in mixed forests was focused on root growth,regardless of forest type and tree species,tree growth would focus on stem growth from slope position to bottom.There was a significant negative correlation between the mixed effect of C.lanceolata and E.sylvestris and the site index,the soil available phosphorus was the main limiting factor for the growth of the mixed forests.The mixed forest of C.lanceolata and E.sylvestris might improve stand growth,and the mixed stands had better adaptability to poor site conditions.