山东滨海盐碱地柽柳林下微生物量变化特征及其影响因素

The changing characteristics and influencing factors of the microbial biomass under shrub of Tamarix in Shandong coastal saline-alkali soil

以山东昌邑国家级海洋生态特别保护区内柽柳林下土壤微生物为研究对象,测定了其微生物量变化.结果表明:研究区细菌、真菌及古菌基因平均拷贝数分别为8.24×106copies·g-1、1.51×104copies·g-1和2.85×104copies·g-1,微生物量碳、氮平均值分别为140.54 mg·kg-1和29.19 mg·kg-1.自密集区经稀疏区到边缘区,随植被盖度的降低,微生物量呈现降低的趋势.相关分析表明,不同植被盖度所造成的有机质输入的差异是造成这种变化规律的主要因素.

Soil samples were collected under shrub of Tamarix in Marine Ecology Special Reserve,a national reserve in Changyi city of Shandong Province, to determine the microbial biomass. Results show ed that ribosomal gene copies of bacteria,fungi,and archaea are 8. 24 × 10^6 copies · g^-1,1. 51 × 10^4 copies · g^-1,2. 85 × 10^4copies·g^-1,respectively. The mean microbial biomass carbon and nitrogen are 140. 54 mg·kg^-1and 29. 19 mg · kg^-1,respectively. From the dense zone,the sparse zone to the marginal zone,microbial biomass decreases with vegetation coverage. Correlation analysis indicates that the differences in organic matter input caused by vegetation coverage are the main factors for variance of microbial biomass. The establishment and grow th of Tamarix provided stable grow th conditions for soil microorganisms in the shallow layer of soil,resulting in similar microbial biomass under shrub of Tamarix from different habitats. Yet,there are large differences in microbial activity,e. g.,a significant high microbial biomass carbon and nitrogen in costal saline-alkali soil than that in desert ecosystem.