【摘要】 以干旱、半干旱地区荒漠草原土壤为研究对象,研究氮(N)、磷(P)添加对荒漠草原0～30 cm土层土壤溶解性有机碳、微生物生物量碳和易氧化有机碳含量及有效率、土壤碳库管理指数(CPMI)、敏感指数(SI)的影响,探讨N、P添加后土壤溶解性有机碳、微生物生物量碳和易氧化有机碳对碳库管理指数的表征作用。结果表明,N添加、P添加或NP共同添加对荒漠草原0～20 cm土壤溶解性有机碳的累积有显著促进作用,但对0～20 cm土壤微生物生物量碳无显著影响。NP共同添加显著增加0～10 cm土层土壤易氧化有机碳。0～30 cm土层N、P添加的土壤溶解性有机碳的各项敏感指数均高于易氧化有机碳,说明土壤溶解性有机碳对短期N、P添加反应最敏感,因此可作为荒漠草原短期N、P添加对土壤有机碳变化的指示物。短期N、P添加能提高碳库管理指数,增加土壤有机质含量,促进荒漠草原土壤恢复。更多还原

【Abstract】 In this study, nitrogen(N) and phosphorus(P) were added to desert grasslands in arid and semiarid regions. We determined the concentration and efficiency of dissolved organic carbon(DOC), microbial biomass carbon(MBC), and easily oxidized organic carbon(EOC), and we calculated carbon management indicator(CMI) and sensitivity index(SI) values. The results showed that nutrient addition(N, P, and N+P) significantly increased the soil DOC concentration in the 0-20 cm layer, but did not affect the soil MBC concentration in the 0-20 cm layer. The soil EOC concentration in the 0-10 cm layer was significantly increased by the addition of N+P. In the 0-30 cm layer, all sensitivity indexes of soil DOC were higher than those of soil EOC, indicating that soil DOC was more sensitive than soil EOC to short-term N and P addition. Therefore, soil DOC could be used as an indicator of the changes in SOC after short-term N and P additions to desert grassland. The CMI and soil organic matter content were increased by short-term N and P addition. These results indicate that short-term N and P addition can promote the restoration of soils in desert grassland.更多还原