Construction of Full-cycle Oriented Cultivation Technology Model for Large-diameter Timber of Chinese Fir
[Objective]The purpose of this study is to establish a full-cycle oriented cultivation technology model for Chinese fir large-diameter timber that can be applied in different producing areas.[Method]Based on survey data from 1 044 sample plots,including temporary plots in different Chinese fir production sites and permanent plots of the Chinese fir spacing trial more than 40 years,six key elements of large-diamet-er timber cultivation—site index,initial planting density,first thinning time,retention density,rotation age,and timber yield—were analyzed and determined considering the three stages of afforestation,silviculture,and harvest.[Result]The production of large-diameter timber was found to be more favorable with great-er site index and lower initial planting density.For the cultivation of Chinese fir large-diameter timber,the suitable stands should be site index with more than 16 and planting density with 1 667～3 333 trees·hm-2.When the total basal area reaches 23 m2·hm-2,the stand age could be used to determine the stand's first thinning period of time.The retention density of a stand with a certain site class could be determined by the double criteria that large-diameter timber outturn rate is more than 50％and large-diameter timber outturn is more than 200 m3·hm-2,and the site class requirement.According to the relationship model between the large-diameter timber outturn rate and the stand age under different site classes,the outturn rate of large-diameter timber=50％was substituted to obtain the corresponding reference rotation age of different site classes,and then the relationship between these values of rotation age and the corresponding site classes was constructed,allowing the rotation age of a stand with a specific site class to be determined.The Richards function,including factors of site index and stand density,could have good performances on pre-dicting DBH,large-diameter timber outturn,large-diameter timber outturn rate and total stand stocking,and the prediction accuracy was close to or above 80％.[Conclusion]The establishment of the"three stages-six determinations"full-cycle directional cultivation technology model for Chinese fir large-diameter timber can provide scientific support for the construction of large-diameter timber forests of Chinese fir,fast grow-ing forests and national reserve forests.
Chinese firlarge-diameter timberfull-cycleoriented cultivationtechnology model
万方数据
维普
