不同疏伐密度对红松结实量的影响

Effects of Different Thinning Densities on Cone Quantity of Pinus koraiensis

2017年对吉林省通化县三棚林场的19年生红松人工林采用保留株数法进行密度疏伐,2020年开始连续3年对不同密度处理下的红松单株结实量进行调查分析,计算单位面积(1 hm 2)平均结实量。结果表明:连续3年的红松单株平均结实量在不同区组间均达显著差异水平(P<0.05),2021年和2022年红松单株平均结实量在不同密度处理间均差异显著(P<0.05),2020年和2021年红松单株平均结实量在不同密度与区组的互作间均差异极显著(P<0.01);各年度红松单株平均结实量的表型变异系数变化范围为172.58%~342.44%,显著的差异与高的变异系数有利于最佳密度处理的筛选。2020年单株平均结实量在3 m×6 m的密度处理下最大,为1.05个,2021年和2022年的单株平均结实量均随着林分密度的减小而增大,在6 m×6 m的密度处理下最大,分别为2.33个和5.13个。2020-2022年,单位面积的平均结实量均在密度处理为3 m×6 m时最大,分别为583.33个、688.89个和1594.44个。

The density thinning method was adopted in the 19-year-old Pinus koraiensis plantation in Sanpeng Forest Farm of Tonghua County in Jilin Province in 2017.The cone quantity per plant with different densities was investigated and analyzed in 2020,2021 and 2022,respectively.The average cone quantity per unit area(1 hm 2)with different densities was calculated.The results showed that the cone quantity per plant was different significantly(P<0.05)among different blocks for three consecutive years.There were significant differences(P<0.05)in the cone quantity per plant among different densities in 2021 and 2022.There were extremely significant differences(P<0.01)in the cone quantity per plant among different blocks×densities in 2020 and 2021.The phenotypic variation coefficient of the cone quantity per plant in each year ranged from 172.58%to 342.44%,and the significant difference and high variation coefficient were conducive to the screening of the optimal density.In 2020,the average cone quantity per plant with the density of 3 m×6 m was 1.05 that was the maximum.In 2021 and 2022,the average cone quantities per plant increased with the decrease of the density and reached the maximum with the density of 6 m×6 m.Those were 2.33 and 5.13,respectively.In the three years from 2020 to 2022,the average cone quantities per unit area reached the maximum with the density of 3 m×6 m,and those were 583.33,688.89 and 1594.44,respectively.