岩溶区不同土地覆被方式对土壤团聚体有机碳的影响

发布时间：2018-03-29 02:37

本文选题：岩溶区　切入点：土地覆被　出处：《生态环境学报》2017年09期

【摘要】：分析不同土地覆被方式土壤有机碳的差异和特点有助于深入研究岩溶区碳循环的特点和规律。以西南岩溶地区森林、灌丛和果园3种土地覆被方式为研究对象,对0~100 cm各层土壤总有机碳及团聚体有机碳的差异和特征进行研究,结果表明:(1)3种土地覆被方式以森林土壤总有机碳含量最高(12.53~39.33 g·kg~(-1)),灌丛次之(8.48~27.99 g·kg~(-1)),果园最低(8.40~18.61 g·kg~(-1)),不同土地覆被方式土壤总有机碳不仅在0~20 cm差异显著,而且在40~70 cm土层也有明显差异(P0.05);各土地覆被方式0~100 cm各层土壤均以0.25 mm水稳性大团聚体为主,果园土壤2 mm团聚体质量分数在0~90cm土层显著低于森林和灌丛(P0.05)。(2)土地覆被方式对土壤2 mm大团聚体内有机碳含量的影响最为显著,森林土壤2 mm团聚体有机碳的含量为12.32~39.88 g·kg~(-1),在0~100 cm各层均显著高于灌丛和果园,并且灌丛土壤2 mm团聚体有机碳的含量在0~30 cm和40~90 cm土层也显著高于果园(P0.05)。另外,果园土壤0.25 mm微团聚体内有机碳的含量明显高于0.25 mm大团聚体,然而森林0~100 cm土层和灌丛0~30 cm土层各粒级团聚体有机碳含量没有显著差异(P0.05)。(3)3种土地覆被方式,0.25 mm大团聚体对土壤有机碳的贡献均高于0.25 mm微团聚体;森林、灌丛和果园0.25~2 mm团聚体对有机碳的贡献率分别为40.31%~67.76%,41.99%~59.38%和48.72%~68.18%,是贡献率最高的团聚体;不同土地覆被方式之间2 mm团聚体对有机碳的贡献差异最为显著,森林土壤明显高于灌丛和果园;3种土地覆被方式中果园土壤0.25mm微团聚体对有机碳贡献率相对较高,其0.053~0.25 mm微团聚体对有机碳的贡献率为13.08%~26.98%,仅次于0.25~2 mm大团聚体。
[Abstract]:Analyzing the differences and characteristics of soil organic carbon in different land cover patterns is helpful to study the characteristics and rules of carbon cycling in karst areas. The differences and characteristics of total organic carbon (TOC) and aggregate organic carbon (OOC) in 0 ~ 100cm soil layer were studied. The results showed that the highest content of total organic carbon (TOC) in forest soil was 12.53 ~ 39.33 g 路kg ~ (-1), followed by thicket (8.48 ~ 27.99 g 路kg ~ (-1)), and the lowest in orchard was 8.40 ~ 18.61 g 路kg ~ (-1) ~ (-1), the difference of soil total organic carbon in different land cover was not only in 0 ~ 20 cm, but also in different land cover. There was also a significant difference in the soil layer of 40 ~ 70 cm (P 0.05), and the 0 ~ 100 cm soil layer of 0 ~ 100 cm of land cover was mainly composed of 0.25 mm water stable large aggregate, and there was no significant difference in the soil layer between 0 and 100 cm soil layer. The soil mass fraction of 2 mm aggregate in orchard soil was significantly lower in 0~90cm soil layer than that in forest and thicket (P0.05. 0. 0. 0. 0. 2) the soil cover pattern had the most significant effect on the content of organic carbon in soil 2 mm agglomeration. The organic carbon content of 2 mm aggregate in forest soil was 12.32 ~ 39.88 g 路kg ~ (-1) ~ (-1), which was significantly higher than that in shrub and orchard at 0 ~ 100 cm, and the content of organic carbon in 2 mm aggregate in 0 ~ 30 cm and 40 ~ 90 cm soil layer was significantly higher than that in orchard (P _ (0.05)). The content of organic carbon in the soil of the orchard was significantly higher than that in the soil of the orchard. However, there was no significant difference in the content of organic carbon between 0 ~ 100 cm soil layer of forest and 0 ~ 30 cm of shrub soil layer. The contribution of 0.25 mm large aggregate to soil organic carbon was higher than that of 0.25mm microaggregate in forest, and there was no significant difference in organic carbon content between 0. 05 cm soil layer and 0 ~ 30 cm shrub soil layer. The contribution rate of 0.25mm agglomerates from shrub and orchard to organic carbon was 40.31 and 47.761.99% and 48.72cm, respectively, which were the highest, and the contribution of 2mm aggregates to organic carbon was the most significant among different land cover ways, and the contribution of 2mm agglomerates to organic carbon was the most significant among different land cover patterns, and 49.38% and 48.72mm aggregates contributed the highest contribution to organic carbon, respectively. The contribution rate of 0.25mm microaggregate to organic carbon was higher in forest soil than that in shrub and orchard mulch, and the contribution rate of 0.053 ~ 0.25mm microaggregate to organic carbon was 13.08 ~ 26.98%, second only to 0.252mm aggregate.
【作者单位】：聊城大学环境与规划学院;国土资源部/广西岩溶动力学重点实验室(中国地质科学院岩溶地质研究所);
【基金】：国家自然科学基金青年基金项目(41402326) 岩溶动力学重点实验室开放基金课题(KDL201506) 聊城大学博士科研基金项目
【分类号】：S153.6

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