长白山白桦林细根的生产力及其周转

Productivity and Turnover of Fine-roots of Betula platyphylla Forest in Changbai Mountain

通过土钻法和分解袋法对长白山30a生白桦林的细根生产力和周转进行分析。结果表明:65%以上的细根集中在0～10cm的土壤层中。在生长季内,活细根的平均生物量为2.882t/hm2,死细根的平均生物量为0.308t/hm2,细根的生长高峰出现在7月。经过估算,白桦林的细根年生产量为4.246t/hm2,年周转为1.47次,年分解率为58.26%。白桦林细根分解较快,在土壤养分归还方面能发挥重要作用。

Productivity and turnover of fine-roots of 30-year-old Betula platyphylla forest in Changbai Mountain were studied through soil auger method and litter bag technique.The result showed that over 65% of fine roots were in the top 0～10 cm of soil layers.At growing period,the average biomass of living fine-root was 2.882 t/hm2;the average biomass of dead fine-roots was 0.308 t/hm2.The high value of fine-root biomass showed in July;the annual productivity of fine-root biomass in Betula platyphylla forest was 4.246 t/hm2,the turnover rate was 1.47 times per year and the annual decomposition rate was 58.26%.The fine-roots of Betula platyphylla forest have quick decomposition rate,so it plays an important role in soil nutrient return.