基于双侧t检验分析的密度调控对米老排中龄人工林生长研究

Study on the Density Regulation on Growth of Middle-age Plantation in Mytilaria laosensis Based on Two-sided T-test Analysis

为有效维护人工林的生态,科学合理地减少人力物力的投入成本,并探析密度调控对米老排人工林生长发育的影响规律,为米老排的生长、修剪以及其他培育措施提供理论依据,以米老排为研究对象,主要运用双侧t检验分析方法以及相关的数理统计法来探析密度调控对米老排中龄林的生长影响,采用优势木和平均木两种样本对象进行数据分析,对间伐密度在米老排的胸径生长、树高生长和单株材积及其他方面进行了科学地分析。结果显示:在种植米老排初期时,米老排的生长比较依赖于外界环境,需要大约3年的抚育时间;成熟的米老排林分天然更新,种源较为充足。采伐作业对于促进米老排人工林更新的密度和频度的影响都较为显著,林分密度;需要进行调控,从蓄积角度上来看,密度调控应当不小于500株/hm^(2),从胸径生长角度来看,最小密度不宜小于300株/hm^(2)。密度调节会影响生长过程、胸径和树的高度;林分管理强度越高,平均树高生长和最大年生长越低,树高成熟时间越快;林分管理强度直径越小,胸径平均增长越高,胸径成熟年龄越晚;林分管理强度高,树高总增长低,平均高增长低,平均高增长和年增长最大,材积平均生长量和连年生长量最大值出现的时间越晚。

In order to effectively maintain the ecosystem of the plantation,scientifically and reasonably reduce the input cost of human and material resources in the future development,and analyze the impact of density regulation on the growth and development of Mytilaria laosensis plantation,so as to provide a theoretical basis for the growth,pruning and other cultivation measures of Mytilaria laosensis plantation.This study took Mytilaria laosensis as the research object,mainly uses the two-sided t-test analysis method and the related mathematical statistics method to analyze the impact of density control on the growth of Mytilaria laosensis mid-age forest,uses the dominant tree and the average tree to carry out data analysis,and scientifically analyzed the thinning density in the DBH growth,tree height growth,single tree volume and other aspects of Mytilaria laosensisi.According to the results,at the early stage of planting rice old row,the growth of rice old row is relatively dependent on the external environment,which requires about 3 years of nursing time.The mature Mytilaria laosensis forest is naturally renewed and the provenance is relatively sufficient.The cutting operation has a significant impact on the density and frequency of the regeneration of Mytilaria laosensis plantation.It needs to be regulated.From the perspective of accumulation,the density regulation should not be less than 500 plants/hm^(2),and from the perspective of DBH growth,the minimum density should not be less than 300 plants/hm^(2).Density regulation will affect the growth process,DBH and tree height.The higher the stand management intensity,the lower the average tree height growth and maximum annual growth,and the faster the tree height maturity time.The smaller the diameter of stand management intensity,the higher the average growth of DBH,and the later the maturity age of DBH.The stand management intensity is high,the total growth of tree height is low,the average height growth is low,the average height growth and annual growth are the largest,and the average volume growth and the maximum annual growth appear later.