主伐方式对马尾松林地土壤理化性质影响的研究

Influence of Principal Felling System on Soil Properties of Physical Chemistry of Pinus massoniana Lamb. Forest

择伐使土壤容积质量略有增加，而皆伐却有明显增加；土壤毛管孔隙度变化不大，非毛管孔隙度和总孔隙度明显下降；土壤持水能力也明显降低。皆伐后有机质、全氮和水解性氮损失严重。因此，在坡度较大的南方山地，主伐方式选择不当，会引起土壤肥力的严重衰退，影响幼林的生长。

Through the analyses of effect of different harvest cutting systems on physical and chemical properties of the soil (0～20cm) in Pinus massoniana Lamb.forest lands before and after harvesting,the results showed that all kinds of soil pore decreased,but bulk density increased in cutting areas in comparison with the forest lands.Especially,the changes were obvious in clear cutting area.The results also indicated that the most of chemical properties of the soil,such as organic matter,content of nitrogens,etc.were less in cutting areas than in the forest lands.So the selection unsuited of harvest cutting systems would lead to soil degradation.