黄土丘陵沟壑区天然植被恢复类型对土壤微生物碳的影响

Effect of Natural Vegetation Regeneration Types on Soil Microbial Biomass Carbon on the Loess Plateau

采用野外调查取样结合室内测定分析的方法,研究黄土丘陵沟壑区不同天然植被恢复类型土壤微生物量碳和有机质的变化规律,探讨植被恢复过程中土壤微生物量碳和有机质的关系。结果表明：植被恢复后的土壤微生物量碳和有机质含量较农田均显著提高,植被恢复对土壤微生物量碳和有机质的影响主要表现在0~10 cm土层;土壤微生物量碳和有机质在0~10 cm土层随恢复年限呈增加趋势,植被类型中乔木混交林土壤微生物量碳含量最大,乔木林的土壤有机质含量最大。不同恢复年限的草地,其土壤有机质与土壤微生物量碳在0~10 cm土层呈正相关关系,在10~20 cm呈负相关关系;不同恢复类型的植被,其土壤有机质和微生物量碳的关系与不同恢复年限的草地正好相反,其在0~10 cm土层负相关,在10~20 cm呈正相关。上述结果表明,黄土高原植被恢复有利于提高表层土壤微生物量碳和有机质含量;植被恢复类型和年限对土壤微生物量碳与有机质的关系影响不一致。

Based on the field survey and laboratory measurement,the dynamic changes of soil microbial biomass carbon（ SMBC） content and organic matter（ SOM） content under different vegetation regeneration types and ages were investigated,and their relationships were explored in our study. The results showed that both the SMBC and SOM contents were significantly increased after regenerating the vegetation,and their increase occurred mainly in soil layer of 0- 10 cm in depth. The SMBC and SOM contents in 10 cm topsoil were increased with the increase of vegetation regeneration age. The SMBC content was the highest in soil under the arbor mixed forest,and the SOM content was the highest in soil under the arbor forest. There was a positive correlation between the SMBC and SOM contents in 10 cm topsoil and the grassland regeneration age,but a negative one in soil layer of 10- 20 cm in depth. However,there was an opposite correlation between the SMBC and SOM contents in different soil layers and the different vegetation types. These results indicated that the vegetation regeneration on the Loess Plateau was benefited to the improvement of the SMBC and SOM contents in topsoil layer; the relationships between the SMBC and SOM contents under different vegetation types and regeneration ages were different,and the potential mechanism needs to explore in the future study.