摘要
在青藏高原东祁连山段,嵩草草地、金露梅灌丛草地、珠芽蓼-嵩草草地、高山柳-金露梅灌丛草地、禾草草地、沼泽草地上,分层(0～10 cm,10～20 cm)采集了土壤样品,分析了土壤有机C、全N和微生物量C、N含量的关系.结果表明:在一定范围内,青藏高原东祁连山段高寒草地土壤微生物量C、N含量与土壤有机C、全N表现出了很好的相关性.不同草原类型的表层土壤有机C含量顺序为:高山柳-金露梅灌丛草地>珠芽蓼-嵩草草地>嵩草草地>金露梅灌丛草地>沼泽草地>禾草草地;土壤全N含量顺序为:嵩草草地>金露梅灌丛草地>高山柳-金露梅灌丛草地>珠芽蓼-嵩草草地>沼泽草地>禾草草地.土壤微生物量C随着土层深度的增加而减少,微生物量C变化在251.6～1 562.5 mg/kg之间,微生物量N变化在18.5～50.9 mg/ kg之间, 微生物量C/N在12～32之间.土壤微生物量碳(Cmic)占土壤有机碳的(Corg)的比例在0.3 %～1.7 %之间.不同草原类型的土壤微生物量C、N含量差异较大.
The soil samplings at two layers （0-10 cm, 10-20 cm） of six distinct alpine grassland forms in the Eastern Qilian Mountains were collected in July, 2004. The soil organic carbon （C）and total nitrogen N （N） were analyzed, and the soil microbial biomass C（Cmic）andN（Nmic）were determined by an extraction method. The results showed as follows： the contents of Cmic and Nmic of the alpine grassland showed significant correlations with soil organic carbon and total nitrogen. Soil organic carbon in the soil layer 0-10 cm showed a decreasing trend as： Salix cupularis-potentilla fruticosa shrubs〉 Polygonurn viviparum -Kobresia meadow 〉 Kobresia meadow 〉 Potentilla fruticosa shrubs 〉 wet meadow〉 grass steppe. Total nitrogen in the soil layer 0- 10 cm showed a decreasing trend as. Kobresia meadow〉 potentilla fruticosa shrubs〉Salix cupularis- potentilla fruticosa shrubs〉 Pol ygonurn viviparum- Kobresia meadow〉Grass steppe. Soil microbial biomass C and N of the surface soil were more than that of deeper layer of soil. Soil microbial biomass C and N ranged from 251.6-1 562.5 mg/kg and 18. 5-50. 9 mg/kg respectively, Cmic/Nmic from 12-32,and Cmic/C from 0.3 %-1.7 %. Soil microbial biomass C and N diversed with different types of grassland. Effect of grazing on soil microbial biomass depended on grassland types and grazing intensity.
出处
《甘肃农业大学学报》
CAS
CSCD
2005年第5期639-645,共7页
Journal of Gansu Agricultural University
基金
国家自然基金
中国科学院百人计划项目(30371021)
关键词
东祁连山
高寒草地
土壤微生物量
C
N
Eastern Qilian Mountains
alpine grassland
soil microbial biomass
carbon
nitrogen
