不同林龄和坡位水杉人工林生长状况的比较

对南方山地不同年龄和不同坡位水杉人工林的生长状况进行全面调查与比较分析,结果表明:27 a生水杉胸径速生期出现时间比32 a生水杉提前4 a,其持续时间也延长2 a,表明27 a生水杉人工林生长状况明显好于32 a生林分;不同林龄水杉林树高速生期持续时间均为6 a,但27 a生水杉人工林树高速生期出现时间提前11 a;27 a生水杉人工林蓄积量比32 a生水杉林多1.4075 m3,其年均蓄积量也比32 a生多;下坡的水杉人工林生长状况最好,中坡其次,上坡最差。

Comparison of the growth of Metasequoia glyptostroboides plantations with different ages and slopes

The growth of Metasequoia glyptostroboides plantations with different ages and slopes in mountain areas of South China was studied.The results were as follows: the diameter fast-growing period of 27-year-old Metasequoia glyptostroboides was 4 years earlier than 32-year-old M.glyptostroboides;the period lasted for 8 years,which was 4 years earlier than 32-year-old M.glyptostroboides;the height fast-growing period of 27-year-old M.glyptostroboides was 11 years earlier than 32-year-old M.glyptostroboides;the plantation stock of the 27-year-old M.glyptostroboides was 1.4075 m3 more than 32-year-old M.glyptostroboides,the average volume of 32-year-old M.glyptostroboides was less than 27-year-old M.glyptostroboides.It was suggested that the productivity of M.glyptostroboides plantation on lower slopes was the largest,that on middle slopes was the second,and that on upper slopes was the lowest.