松栎混交林土壤微生物数量与土壤酶活性及土壤养分关系的研究

The Relationship among Microbial Quantities, Enzyme Activities and Nutrients in Soil of Pine-oak Mixed Forest

对秦岭山地松栎混交林土壤微生物数量特征及其与土壤酶、土壤理化性质之间的关系进行了研究。结果表明：（1）林地土壤中三大类群微生物的数量在土层间自上而下急剧减少，表层土壤微生物数量最多，占土壤剖面总数的51．55％以上。（2）土壤微生物数量以细菌为主，占总数的99．70％～99．96％；放线菌次之，占总数的0．04％-0．30％；真菌最少，小于0．01％。（3）密度中等（1500。1650株hm^-2）的林分能显著增加土壤中的微生物数量。（4）土壤细菌、放线菌、真菌数量与土壤过氧化氢酶、脱氢酶、脲酶、蔗糖酶及土壤养分含量和土壤总孔隙度呈极显著正相关，与土壤容重呈极显著负相关；土壤放线菌、真菌数量与土壤含水量呈显著正相关；土壤细菌数量与土壤pH值呈显著正相关。

The relationships among microbial quantities, enzyme activities and nutrients in soil of pine-oak mixed forest were investigated in Qinling mountains of central China. The results were as follows： （1） With the increase of soil depth, the amount of three groups of soil microbes decreased rapidly. Microbial quantities were the highest in the surface soil, over 51.55% of the total. （2） Among soil microbial quantities, bacteria were predominant, actinomyees were the secondary and fungi were the least, accounting for 99.70% - 99.96%, 0.04% - 0.30% and less than 0.01% of the total microbes respectively. （3） Soil microbial quantities increased significantly in forestland at moderate stand density （1500 - 1650 trees hm-2）. （4） The amount of soil bacteria, actinomyces and fungi had remarkable positive correlation with soil catalase, dehydrogenase, urease, invertase, soil nutrients and soil total porosity. However, the amount of soil bacteria, actinomyces and fungi had remarkable negative correlation with soil bulk density. Soil actinomyces, fungi had positive correlation with soil water content, and soil bacteria had positive correlation with soil pH.