落叶松人工林地力衰退研究现状与进展

对近１０年来国内有关落叶松人工林地力衰退问题的研究结果表明：落叶松人工林对土壤性质有不良影响，具体表现为土壤密度、孔隙度、结构、持水量、酸度、有机质含量、养分元素（Ｎ、Ｐ、Ｋ、Ｃａ、Ｍｇ等）含量及有效性、土壤微生物数量及酶活性等一系列肥力指标质量的下降和某些条件下第二代落叶松人工林生产力的衰退。从人工林生态系统的多样性和稳定性、落叶松人工林养分循环特点、落叶松凋落物对土壤性质的影响及营林生产活动的干扰等多方面分析了地力衰退的原因。最后，对调整群落结构、合理轮作、林地施肥及土壤改良等一系列防止落叶松人工林地力衰退的对策和措施进行了总结和评价

Research State and Advance on Soil Degradation under Larch Plantations

This paper summarized the results of recent researches on soil degradation under larch (L. gamelinii, L. olgensis) plantations in Northeast China. Most result demonstrated that, larch plantations have negative influence on forst soils. The soil degradation could be illustrated by the depletion of forest plantation productivity and the decline in many soil properties, such as bulk density, soil porosity, soil structure, acidity, organic matter content and humus composition, total content of nutrient elements (N,P,K,Ca,Mg,etc.) and their availability, the amount of soil microorganisms and soil enzyme activity. The mechanism of soil degradation was analysed from the view point of ecosystem, nutrient cycling, soil chemistry and anthropogenic disturbance. Finaly, the strategy and measures to prevent soil degradation were put forward and discussed, including stand structure regulation, shifting culture, fertilization and soil amelioration etc.