修枝强度对樟树幼林生长和光合特性的影响

[Objective]The response of pruning heights to the growth and photosynthetic characteristics of young Camphora officinarum trees was investigated to provide technical support for targeted cultivation of C.officinarum plantations..[Method]A 5-year-old C.officinarum artificial forest was used as the research object,three pruning heights treatment groups with pruning branches below 1/4,1/3,and 1/2 of tree height were established,and the non-pruning group was used as the control to analyze the effects of pruning height on the growth,wound healing,and photosynthetic characteristics of C.officinarum trees.[Result]The results showed that the breast height(DB)and individual volume(V)growth of C.officinarum were inhibited in the first year after pruning,showing a trend of decreasing with the increase of pruning intensity.In the second year after pruning,the DB and V growth of each treatment were increased,and the V growth of T2 treatment was significantly higher than that of CK.There was no significant difference in the total increase in DB among the treatments.The total increase in H among the pruning treatments was significantly higher than that of CK.The maximum increase in H and V was observed at T2,which was significantly higher than other treatments(P<0.05).The healing rate of pruned wounds showed a gradually increasing trend with the increase of pruning height and wound height above ground,and the complete healing rate of pruned wounds showed a gradually increasing trend with the increase of wound height above ground.T1 and T2could significantly improve the net photosynthetic rate(Pn)and instantaneous carboxylation efficiency(CE)of leaves(P<0.05).[Conclusion]Taking all factors into consideration,1/3 pruning height is the appropriate pruning height for young plantation of C.officinarum,which does not affect normal growth and can promote the good construction of young plantation.