Impacts of Different Intermediate Cutting on Crown Structure of Manglietia yuyuanensis in Mixed Stands with Cunninghamia lanceolata

The stands of 17-year-old and 15-year-old Manglietia yuyuanensis mixed with C.lanceolata （the ratios of C.lanceolata to M.yuyuanensis was 7∶3） at Shaxian County in Fujian Province,which respectively given different intermediate cutting in 10th year and 13th year were studied.The crown structure （including vertical distribution of primary branches, crown form, vertical changes of branch inclinations, vertical distribution of leaf area and cumulative leaf area index） of M. yuyuanensis in mixed stands were studied by asynchronous speed growth model.The results showed that different intermediate cutting patterns had significant effects on the crown structure. With timely intermediate cutting,most trees of M.yuyuanensis were with coniform crowns, otherwise crown form appeared parabolical cylinder crowns. The conical-shaped crown,large branch inclination and higher leaf area index were contributed to the absorption of the sunlight and the silviculture of large-diameter wood of M.yuyuanensis. The cumulative leaf area index of M.yuyuanensis could be estimated by the index models,respectively,ACLAI=2.6211Z0.1318е0.0417Z（R2=0.941　8）　and BCLAI=1.754　6Z0.6122е-0.1411Z（R2=（0.9923））.Validation on the data showed that the model of M.yuyuanensis leaves area could give more accurate estimation.