湖南崀山森林公园不同植被条件下土壤微生物量及酶活性研究

Changes of soil microbial biomass and enzymatic activities among restoration stages of Langshan Forest Park,Hunan Province

以崀山森林公园植物群落的灌木阶段（A）、乔灌阶段（B）和乔木阶段（C）的土壤为研究对象,分别研究了3个阶段0～20 cm,20～40 cm土层土壤中微生物量及土壤酶活性.结果表明,随着土层深度的增加,土壤有机质、全氮、全磷含量呈降低的变化趋势,崀山森林公园植物群落不同恢复阶段土壤微生物量碳、微生物量氮、微生物量磷含量,以及微生物量碳、氮、磷对土壤有机质、全氮、全磷的贡献率均表现为0～20 cm大于20～40 cm.0～20 cm土层中微生物量碳、微生物量磷以乔木阶段最高,微生物量磷在0～20 cm、20～40 cm均表现为C＞A＞B.微生物量氮以乔灌阶段最低.土壤微生物量碳、氮、磷对土壤有机质、氮、磷的贡献率均表现为0～20 cm高于20～40 cm.就崀山森林公园植物群落A、B、C三个阶段的土壤酶活性而言,0～20 cm土层中蔗糖酶、脲酶、磷酸酶、蛋白酶、过氧化氢酶活性显著高于20～40 cm （P＜0.05）,蔗糖酶高出20～40 cm 15.14％～35.69％.0～20 cm土层的脲酶活性表现为C＞B＞A,且差异显著（P＜0.05）,蛋白酶活性以灌木阶段最高,分别是乔灌、乔木阶段的1.244,1.442倍和1.680,1.713倍;中性磷酸酶以乔灌阶段的活性最高,碱性磷酸酶则以灌木阶段的最高.3个不同恢复阶段0～20 cm土层的过氧化氢酶活性无显著性差异（P＞0.05）.

The study on soil microbial biomass and the enzyme activities including urease,acidic phosphatase,catalase,protease,amylase and sucrase was carried out in shrub,shrub-tree and tree of plant communities in Langshan Forest Park in Hunan,China.In each forest,the tested soil was fetched back from different depths,0-20 cm and 20-40 cm.The results indicated that the content of organic matter （OM）,total nitrogen （TN）and total phosphorus （TP） were decreased with soil depth increasing.The content of soil microbial biomass carbon （SMBC）,microbial biomass nitrogen （SMBN）,microbial biomass phosphorus （SMBP）,and the contribution rate between SMBC/OM,SMBN/TN,and SMBP/TP in the 0-20 cm soil were higher than that in 20-40 cm.Among the stages of A,B and C,the content of SMBC and SMBP in stage of tree were the highest.The trend of the content of SMBP in 0-20 cm and 20-40 cm was C＞A＞B.When we came to the enzyme activities in the stage of A,B and C of the Langshan Forest Park plant communities,the activity of urease,acidic phosphatase,catalase,protease,amylase and sucrase in soil layer 0-20 were higher than that in soil layers 20-40 cm.The activity of sucrase in soil layer 0-20 cm was 15.14％-35.69％,higher than that in soil layer 20-40 cm.The trend of the activity of urease in soil layer 0-20 cm was C＞B＞A and it shown significant difference in this layer.The activity of protease in the stage of bush was 1.244 and 1.442 fold and 1.680 and 1.713 fold in that of stage of shrub-tree and tree respectively.The activity of neutral phosphatase is highest in the stage of shrub-tree while the activity of alkaline phosphatase in the stage of shrub was highest.The activity of catalase shown no significant difference among different recovery stage of A,B and C in soil layer 0-20 cm.