水保所知识产出(1956---)知识库

研究土壤侵蚀—沉积对土壤微生物生物量的影响可以为科学评估土壤侵蚀的环境效应
提供依据。以典型薄层黑土区——黑龙江省宾州河流域为研究区，利用土壤 137 Cs含量估算侵蚀速率，
通过分析流域不同位置和不同坡面部位土壤微生物生物量碳和氮含量以及土壤侵蚀强度的差异，揭示
土壤微生物生物量对土壤侵蚀—沉积的响应规律。结果表明：流域不同位置和不同坡面部位土壤微生
物生物量的分布存在明显差异，并呈现出与土壤侵蚀—沉积空间分布相反的变化趋势。土壤侵蚀速率
在流域的分布为上游＞中游＞下游，在坡面的分布为坡中部＞坡上部＞坡下部；土壤微生物生物量碳
（Microbial biomass carbon，MBC）和微生物生物量氮（Microbial biomass nitrogen，MBN）在流域表
现为下游＞中游＞上游，在坡面表现为坡下部＞坡上部＞坡中部。回归分析表明，MBC、MBN、有机
质（Organic matter，OM）和全氮（Total nitrogen，TN）含量随土壤侵蚀强度的增大而减少。土壤侵蚀
对土壤微生物生物量的分布有重要影响，土壤侵蚀—沉积过程引起土壤养分的迁移和再分布是导致侵
蚀区和沉积区土壤微生物生物量分布产生差异的重要原因。

Soil erosion is a serious problem，causing soil and nutrient losses and altering
physical，chemical and biological properties of the soil. Numerous reports have been published on effects
of soil erosion on soil physicochemical properties. However，little has been done on quantitative analysis of
how soil erosion and deposition affect soil microbial biomass in the black soil region of China. Soil microbial
biomass is a sensitive indicator of changes in the environment，compared with soil organic matter. The
study on impacts of soil erosion and deposition on soil microbial biomass is expected to be able to provide
certain important basis for scientific evaluation of the environmental effects of soil erosion. Therefore，the
study was oriented to investigate response of soil microbial biomass carbon and nitrogen to soil erosion and
deposition，by analyzing soil microbial biomass carbon，microbial biomass nitrogen and erosion rate of the
soils at different locations（the upper stream，middle stream and downstream reaches）in the valley and
different positions（the upper，middle，and lower slope position）on a slope. 【Method】The Binzhou
River Valley，a typical region of black soil thin in soil layer in Northeast China，was taken as the research
area. Contents of microbial biomass carbon and microbial biomass nitrogen in the soils of the sampling sites
different in slope position and location in the valley were measured using the chloroform fumigation extraction
method and erosion rates of the soils estimated using the
137 Cs tracer method. 【Result】Results show
significant differences exist between the soils in spatial distribution of soil microbial biomass，and negative
relationships of the spatial distributions of soil microbial biomass carbon and microbial biomass nitrogen
with that of soil erosion and deposition. On the watershed scale，soil erosion rate declined drastically from
the upper stream down to the middle stream and the lower stream，while both soil microbial biomass carbon
and microbial biomass nitrogen exhibited a reverse trend，being significantly higher in the downstream than
in the upper stream and middle stream. The content of soil microbial biomass carbon was 26.9% and 17.4%
lower，respectively，in the upper stream and the middle stream than in the downstream，and the content
of soil microbial biomass nitrogen 22.9% and 18.1% lower. On the slope scale，soil erosion rate descended
significantly from the middle slope position to the upper slope position and to the lower slope position；but
both soil microbial biomass carbon and microbial biomass nitrogen acted reversely，too，beingsignificantly
higher at the lower slope than at the middle slope. The content of soil microbial biomass carbon was 13.8%
and 20.2%，respectively，lower at the upper slope and the middle slope than at the lower slope，and the
content of soil microbial biomass nitrogen 10.0% and 19.5% lower. Regression analysis shows that the contents
of soil microbial biomass and nutrient decreased linearly with increasing soil erosion rate. Microbial biomass
carbon，microbial biomass nitrogen，organic matter and total nitrogen in the soil were negatively related
with soil erosion rate at an extremely significant level（p＜0.01），respectively. 【Conclusion】Obviously  soil erosion has some profound impacts on spatial distributions of the microbial biomasscarbon and microbial
biomass nitrogen in the soil. The removal and redistribution of soil nutrients caused by the processes of soil
erosion and deposition is the main reason why spatial distribution of soil microbial biomass differ between
erosion and deposition areas.