太岳山油松人工林土壤质量随林龄的演变特征

为探讨土壤质量随林龄的演变特征，以山西太岳山40，60，80年生油松Pinus tabuliformis人工林为研究对象，采用综合指数评估相关的土壤质量状况。结果表明:随着油松人工林龄增加，土壤含水率显著增加，而土壤容重则显著减小；而0~10 cm土层的有机质、全氮、速效钾、铵态氮、硝态氮、有效磷质量分数增加最为显著；80年生油松林的土壤微生物碳氮质量分数分别在10~30 cm和0~20 cm土层显著大于60年生和40年生油松林，而不同林龄油松人工林的土壤质量综合指数为0.568（80年生油松纯林）> 0.500（60年生油松纯林）> 0.363（40年生油松纯林）。说明随着林龄的不断增加，土壤微生物量碳氮质量分数和理化性状得到了提高和改善，太岳山油松人工林的土壤综合质量也不断提升。

Soil quality development in Pinus tabuliformis plantations with different forest ages on Taiyue Mountain

To determine the soil quality of 40-(P₄₀), 60-(P₆₀), and 80-(P₈₀) year-old Pinus tabuliformis plantations on Shanxi Taiyue Mountain, analysis of variance and significance test were used to evaluate significant difference of soil factors, and a composite index were used to evaluate soil quality. Results showed that with an increase in age of the P. tabuliformis forest, soil water content increased markedly; whereas, soil bulk density decreased. The content of organic matter, total nitrogen, available potassium, ammonium nitrogen, nitrate nitrogen, and available phosphorus increased most in the 0-10 cm soil layer. Also, soil microbial biomass carbon in 10-30 cm layers and nitrogen content in 0-20 cm layers of 80-year-old P. tabuliformis forests were much higher than those of 60-year-old and 40-year-old P. tabuliformis forests. The composite indexes of soil quality were 0.568(P₈₀) > 0.500(P₆₀) > 0.363(P₄₀). Thus, with an increase in forest age, soil microbial biomass carbon and nitrogen content as well as physical and chemical properties improved, and soil quality of P. tabuliformis plantations on Taiyue Mountain was enhanced.