治沟造地不同土地利用方式土壤有机碳和易氧化碳分析

Soil organic carbon and readily oxidizable carbon of gully control and land reclamation under different land uses

治沟造地是我国黄土丘陵地区补充耕地,保障粮食安全,恢复生态环境的重要手段。以延安市南泥湾镇为试验地,测定分析了治沟造地区域水田、旱地、柳树林地、松树林地4种典型土地利用方式不同土层深度土壤中有机碳和易氧化碳的含量、分布规律以及易氧化态碳与有机碳的相关关系。结果表明:4种土地利用方式下土壤有机碳和易氧化碳含量均随土层深度的增加而呈现减小的趋势,且不同深度土层土壤有机碳和易氧化碳含量差异均达到显著水平(P<0.05);0~60cm土层深度内,旱地在不同深度土层中的有机碳含量和易氧化碳均低于其它3种土地利用方式;土壤有机碳含量与易氧化碳含量之间的相关性达到显著水平,充分说明土壤易氧化碳含量在一定程度上取决于土壤有机碳的含量;治沟造地改变了区域生态系统,生态系统碳循环受到极大的影响,因此在研究全球碳循环中,治沟造地对生态系统碳循环的影响可作为下一步研究的方向。

Gully control and land reclamation is an important means for replenishing arable land,ensuring food security and restoring the ecological environment in the loess hilly region.To understand the characteristics of soil organic carbon and readily oxidizable carbon in the gully control and land reclamation under different land uses in Nanniwan Town Yan'an,This paper analyzed the contents and distribution of soil organic carbon and readily oxidizable carbon and the relationship between them under four typical land use patterns of paddy field,dry land,willow woodland and pine woodland in the areas.The results showed that the content of soil organic carbon and readily oxidizable carbon in four kinds of land use tended to decrease with the increase of soil depth,and the differences of soil organic carbon and readily oxidizable carbon in different depth soil layers reached significant levels(p<0.05).In 0~60 cm soil depth,the contents of organic carbon and carbon dioxide in dry land in different depths were lower than those in other three kinds.The correlation between soil organic carbon and readily oxidizable carbon reachedasignificant level,which fully shows that the content of readily oxidizable carbon depended on the content of soil organic carbon to a certain degree.The regional ecosystem has been changed by gully control and land reclamation,and the carbon cycle of the ecosystem has been greatly affected.Therefore,in the study of the global carbon cycle,the effect of gully control and land reclamation on the ecosystem carbon cycle can be taken as the direction of further study.