Growth Characteristics of the Mixed Plantation of Chinese-fir with Huangshan Mountain Pine

In order to make a systematic study on the growth characteristics of the mixed stand of Chinese fir with Huangshan pine in the northern limit of Chinese fir distribution,six plots were set up at high altitude in Dabeshan Mountain of Anhui Province.The results showed that the production of the mixed stand was higher than that of pure Chinese fir plantation in the same site,density and management level.The stand volume and total basalarea of the mixed stands were 188.78～289.67 m3/ha and 36.31～42.15 m2/ha respectively,which were higher than those of the pure one at the same age by 60.27%and 19.85% respectively.Biomass of the mixed stands were 128.27～179.18 t/ha,which was higher thanthat of the pure one by 21.99%.here were significant differences in the above groundbiomass between the two types of plantations,a range of 12～16 t/ha·m in the mixedstands,and 10～12 t/ha·m in the pure ones. Results from analysis of tree height-DBH relation of individual tree indicated that growth of tree height of Chinese fir in the mixed stand atyoung growth was significantly promoted,and after 10～12 year-old, DBH growth was evi-dently increased.There was a clear distinction between the DBH growth curves in two types of plantations,that the DBH increment in the mixed stands showed an increasing tendencyand kept a certain increment after fast growing stage,while in the pure Chinese fir stand,after the age of 14 years,DBH increment decreased with the increase of its age. Never the less,the DBH increment of Huangshan Mountain pine decreased evidently with the increase oftree age after 10～12 years old in both types of plantations.