利用根钻法研究了山西关帝山华北落叶松(Larix principis-rupprechtii Mayr)人工林细根生物量的空间分布和季节变化特征。结果表明,华北落叶松不同径级细根生物量随土层深度的增加而逐渐减少,土壤表层(0～10 cm)中各径级细根的生物量最高,Ⅰ级细根(根直径0～1 mm)的生物量在不同土层深度间差异显著(P<0.05);距树干不同水平距离处各径级的细根生物量差异均未达到显著水平(P>0.05)。在0～10 cm土层中,各径级细根生物量的季节变化差异显著(P<0.05),均表现为单峰型,峰值出现在9月份;在10～20 cm和20～30 cm土层中,Ⅰ级和Ⅱ级(根直径1～2 mm)细根生物量季节变化差异显著,Ⅲ级细根(根直径2～5 mm)和Ⅰ级死根(根直径0～2 mm)生物量季节变化差异不显著。

The spatial distribution characteristics and seasonal change dynamics of fine root biomass of Larix principis-rupprechtii Mayr plantation in Guandi Mountain of Shanxi Province were investigated by using the root core method. The results show that the fine root biomass of different diameter classes are decreasing with soil depth increasing, and it reach the highest in 0- 10cm soil depth. The biomass differences of classⅠ fine root (diameter 0- 1mm) in different soil layers are significant (P< 0.05), and the fine root biomass of different diameter classes have no significant differences with different horizontal distances (P> 0.05).The seasonal change of fine root biomass of different diameter classes in  the upper soil layer(soil depth 0- 10cm) is significant (P< 0.05)and shows a single peak curve, and the biomass values reach the maximum in September. In 10- 20cm and 20- 30cm soil depth, the seasonal change of biomass of classⅠ and classⅡ fine roots(diameter 1- 2mm)has significant differences, while that of classⅢ fine root(diameter 2- 5mm) and classⅠ dead root(diameter 0- 2mm) has no significant difference.