Abstract: Ash contents(ASC),ash free caloric values(AFCV)and carbon contents(CAC)of different organs from three species of Castanopsis in Niumulin Nature Reserve experimental region were comparatively studied and carbon stock and standing crop of energy of each tree species plantation,simultaneously,estimated.These three 22-year-old species of Castanopsis were Castanopsis fissa,Castanopsis fargesii,Castanopsis lamonteii.The results showed that ASC increased in the order of leaves,root,branch,trunk for these three species of trees,average ASC of these three species of trees increased in the order of C.lamonteii,C.fargesii,C.fissa.AFCV increased in the order of leaves,branch,trunk,root for these three species of trees,average AFCV of these three species of trees increased in the order of C.lamonteii,C.fissa,C.fargesii.CAC increased in the order of trunk,branch,root,leaves for these three species of trees,average CAC of these three species of trees increased in the order of C.fissa,C.fargesii,C.lamonteii.Difference of ASC,AFCV and CAC were significant among different organs of these three species of trees by t test(P<0.01).In addition to the fact that CAC and AFCV were extremely significant positive correlation,other indexes had no significant correlation.Carbon stock and standing crop of energy of these three species plantation increased in the order of C.lamonteii,C.fargesii,C.fissa.

Key words: Niumulin Nature Reserve, Castanopsis species, ash contents, ash free caloric values