【摘要】 利用平均标准木机械布点法测定了云南省永仁林业局云南松不同龄组林分的根系生物量及其沿土壤剖面深度的分布规律.结果表明,林分根系总生物量随林龄而增加,幼龄林(15～17年)的根系生物量为850t·hm-2,中龄林(30～32年)为1170t·hm-2,成熟林为(>62年)1891t·hm-2.在不同龄组林分中,粗根(>10mm)生物量差异最大(15～123t·hm-2),而中根(5～10mm)(14～16t·hm-2)及小根(<5mm)(53～62t·hm-2)的生物量差异最小.根系生物量沿土壤深度迅速减少,约93%的根系生物量集中分布在0～30cm土层中,深土层(30～115cm)的根系生物量仅占7%左右.更多还原

【Abstract】 With average-tree-specific sampling method,the authors measured the root biomass of Pinus yunnanensis forests with different stand ages in Yongren County,Yunnan Province.The results indicated that total root biomass increased from 8.50 t·hm~-2 in young stand (15～17 yr) to 11.70 t·hm~-2 in middle-aged stand (30～32 yr),and to 18.91 t·hm~-2 in mature stand (60～130 yr).Among different stand age classes,the biomass of coarse roots (>10 mm) varied greatly (1.5～12.3 t·hm~-2 ),whereas those of medium (5～10 mm) and fine(<5 mm)roots showed less variation (medium roots 1.4～1.6 t·hm~-2 ,fine roots 5.3～6.2 t·hm~-2 ).The root biomass of mature stand decreased with soil depth,approximately 93% of total underground biomass being distributed in surface layer (0～30 cm),and only 7% in deeper layer (30～115 cm).更多还原