城市不同森林土壤溶解性有机碳和微生物生物量碳特征

发布时间：2018-11-22 18:03

【摘要】：土壤溶解性有机碳(DOC)和微生物生物量碳(MBC)在生态系统碳循环中发挥重要作用。为了解城市森林土壤DOC含量和MBC特征及影响因素,本研究以合肥市城市森林为对象,分析不同植被类型(水杉、香樟、雪松)土壤DOC、MBC年动态特征及影响因素。结果表明:植被类型对土壤DOC含量影响显著(P0.05),0~30 cm土壤DOC含量年均值为水杉林(80.35 mg·kg-1)雪松林(60.13 mg·kg-1)香樟林(43.36 mg·kg-1),且总体上随土层深度的增加而递减;水杉林、雪松林土壤DOC含量夏秋季高于冬季,而香樟林则6月含量最低;0~30 cm土壤MBC年均值大小依次为水杉林(412.84 mg·kg-1)雪松林(358.85 mg·kg-1)香樟林(283.40 mg·kg-1);不同植被类型土壤MBC总体上随土层深度增加而递减,且夏、秋季较高,冬季较低。相关分析表明:水杉林、香樟林土壤DOC、MBC与有机碳显著正相关(P0.01),而雪松林土壤DOC、MBC与根量呈显著正相关(P0.01),表明雪松林根系分泌及分解转化是其土壤活性碳的重要来源。
[Abstract]:Soil dissolved organic carbon (DOC) and microbial biomass carbon (MBC) play an important role in the ecosystem carbon cycle. In order to understand the characteristics and influencing factors of DOC content and MBC in urban forest soil, the dynamic characteristics and influencing factors of DOC,MBC in soils of different vegetation types (Metasequoia, Cinnamomum camphora, Cedar) were analyzed. The results showed that the effect of vegetation type on soil DOC content was significant (P0.05), and the annual average of soil DOC content was (80.35 mg kg-1) in Metasequoia glyptostroboides forest, (60.13 mg kg-1) in Cedar forest and (43.36 mg kg-1) in Cinnamomum camphora forest. As a whole, it decreases with the increase of soil depth. The soil DOC content of Metasequoia glyptostroboides forest in summer and autumn was higher than that in winter, but the lowest in June in Cinnamomum camphora forest. The annual mean value of soil MBC in 0 ~ 30 cm soil was: Metasequoia (412.84 mg kg-1), Cedar (358.85 mg kg-1), Cinnamomum camphora (283.40 mg kg-1). Soil MBC of different vegetation types decreased with the increase of soil depth, and it was higher in summer and autumn and lower in winter. Correlation analysis showed that soil DOC,MBC was positively correlated with organic carbon (P0.01) in Metasequoia fir and Cinnamomum camphora forest, while soil DOC,MBC was positively correlated with root quantity in Cedar forest (P0.01). The results showed that root exudation and decomposition and transformation were important sources of soil active carbon in Cedar forest.
【作者单位】：安徽农业大学林学与园林学院;

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