长白落叶松人工林细根生物量及其动态研究

以长白山区30年生长白落叶松(Larix olgensis)人工林为研究对象,通过根钻连续取样及分解袋埋藏法,对细根(≤2 mm)生物量及季节动态、细根分解、细根周转进行了研究。结果表明:在长白落叶松人工林生长季,细根平均生物量为3.825 7 t/hm²,其中活细根和死细根分别占84.51%和15.49%; 0～10 cm土层活、死细根生物量分别占林地活、死细根总量的72.09%和50.46%; 细根生物量随土层深度的增加而减少。长白落叶松人工林细根生物量在1年中有明显的季节变化规律,活细根的呈双峰型,死细根的呈多峰型。经细根分解实验计算,长白落叶松人工林细根分解系数k平均为0.001 5,细根年生长量、年分解量和年周转率分别为1.534 8 t/hm²、0.145 0 t/hm²和0.47次/a。

Fine roots biomass and its dynamics of Larix olgensis plantation

This article had studied the biomass, seasonal dynamics, the vertical distribution, decomposition and turnover of the fine roots in Larix olgensis plantation of Changbai mountain from May 2006 to 2007 by using the sequential soil coring method and litter bag technique. The results showed that the average biomass of fine roots was 3.825 7 t/hm² with 84.51% living fine roots and 15.49% dead fine roots. The fine roots mainly distributed in the 0-10 cm of soil layer with 72.09% living fine roots and 50.46% dead fine roots. And with soil layer deepen,the fine roots biomass decreased. The annual change of living and dead fine roots biomass in Larix olgensis plantation had obviously seasonal variation. The living fine roots biomass in different season varied with a double peak curve, and the peaks of the curve appear in May and August. The seasonal change of the dead fine roots biomass showed a multiple peak curve. The average decomposition efficiency(k)was 0.001 5 for Larix olgensis plantation. Net primary productivity, decomposition and annual turnover of fine roots in Larix olgensis plantation were 1.534 8 t/hm², 0.145 0 t/hm² and 0.47 times per year, respectively.