Objective Growth of young Chinese fir trees under 5 cultivation models were studied for the forest building.
Method In a span of several years, 5 forest building models were implemented for the experimentation on Cunninghamia lanceolata. Young plants were cultivated according to a randomized block design of 5 existing models, i.e., Yang 020, Yang 061, Guangxi 2G, Fujian Pushang 3G, and the mixed Yang 020/061. The average diameter at breast height (DBH), tree height, east-west crown width, north-south crown width, individual standing timber volume, and trunk girth classification of the plants were continuously measured throughout the growth period.
Results Significant deviations in DBH, height, crown width, and timber volume were found among most of the trees under different cultivation methods. The differences in DBH, height, and canopy growth were not significant between Yang 061 and Yang 020/061. The stand structure was uniformly distributed under Yang 061. Under Fujian Pushang 3G, a normal distribution on the trunk girth classifications with a solid spatial structure of the fir was observed. Yang 020/061 and Yang 061 had the greatest proportions of trees in the 8-12 cm diameter classes at 60.45% and 41.81%, respectively.
Conclusion The growth of the Chinese fir trees under the cultivation model of Yang 061 showed the highest indices and abundant large-diameter trunks among 5 models. It provided the young forest with desirable development environment and was consider a high-efficiency approach to building forests of Chinese fir in the wild.
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