长白山阔叶红松林采伐迹地土壤养分含量动态研究

采用对比实验，对不同采伐年限的长白山阔叶红松林采伐迹地土壤养分含量变化进行了分析与研究．结果表明，不同采伐年限的采伐迹地土壤养分含量差异很大．林地土壤pH值随着伐后时间的推移而出现一个先下降后上升的过程，表层土壤在伐后5年的酸性最强，10～20cm层土壤在伐后10年酸性最强；土壤有机质含量、全量养分含量和速效养分含量均在采伐初期2～5年增加，随后又迅速减少，尤其是表层土壤变化更为明显；土壤阳离子交换量(CEC)及交换性Ca、Mg也都表现出相同的变化趋势．因此，森林采伐后应及时人工造林、更新进行植被恢复，可将养分固定而减少和防止土壤养分的流失．

Dynamics of soil nutrient contents in cutting forestlands of broad-leaved Korean pine forest on Changbai Mountains

A comparative study was made to analyze the dynamics of soil nutrient contents in different cutting forestlands of broad-leaved Korean pine forest on Changbai Mountains. The results showed that soil nutrient contents in different forestlands with different cutting times had obvious differences. With the cutting time going on after logging, soil pH value had the trend of declining firstly and increasing afterwards. The acidity of the topsoil was the highest after cutting for five years, and that of 10-20 cm soil layer was the strongest after cutting for ten years. The organic matter content as well as the total and available contents of nutrients increased at the first 2-5 years, and then declined rapidly, especially for those in topsoils. The cation exchange capacity (CEC), exchangeable Ca and exchangeable Mg had the same trend. Therefore, after forest cutting, artificial planting and regeneration should be carried out in time to resume the vegetation to reduce and prevent soil nutrient loss.