马尾松林下套种黄花倒水莲根系生长与分布格局

Root Growth and Distribution Pattern of the Intercropped Polygalaaureocauda in Pinus massoniana Plantation

选择19年生马尾松人工林进行间伐,设保留马尾松450(SM1处理)、600(SM2处理)和750株·hm^(-2)(SM3处理)3个处理,分析马尾松不同保留密度下套种黄花倒水莲根系生长与分布格局。结果表明:不同保留密度处理套种黄花倒水莲的根系年生长量与根鲜质量存在显著差异,以马尾松林分密度保留600株·hm^(-2)(SM2处理)套种6年的黄花倒水莲根系生长量最大,其中:根幅生长量达94.9 cm,根系深度达32.8 cm,单株根系鲜质量达506.4 g。黄花倒水莲根系较集中分布在水平距离0~40 cm,垂直深度0~20 cm的区段,与马尾松主根的水平分布和垂直分布交叉较小。SM2处理根鲜质量产值分别比SM1和SM3处理增收347.7元·hm^(-2)和520.2元·hm^(-2),具有显著的经营效益。

A 19-year old Pinus massoniana plantation was selected for thinning,and three treatments including 450 plants·hm^(-2)(SM1 treatment),600 plants·hm^(-2)(SM2 treatment)and 750 plants·hm^(-2)(SM3 treatment)were used to analyze the root growth and distribution pattern of the intercropped Polygala aureocauda under different retention densities of Pinus massoniana.The results showed that there were significant differences in the annual root growth and root fresh weight of the intercropped Polygala aureocauda treated with different retention densities,and the root growth of Polygala aureocauda intercropped with the stand retention density of Pinus massoniana of 600 plants·hm^(-2)(SM2 treatment)for 6 years was the largest,with the root width growth of 94.9 cm,the root depth of 32.8 cm and the root fresh weight per plant of 506.4 g.The roots of Polygala aureocauda were more concentrated in the horizontal distance of 0-40 cm and the vertical depth of 0-20 cm,which were less crossed with the horizontal distribution and vertical distribution of the main roots of Pinus massoniana.Compared with SM1 and SM3 treatments,the output value of root fresh weight with SM2 treatment was increased by 347.7 yuan·hm^(-2) and 520.2 yuan·hm^(-2),respectively,showing significant management benefits.