论文部分内容阅读
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(P<0.05),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(P<0.01),而雪松林土壤DOC、MBC与根量呈显著正相关(P<0.01),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。
Soil dissolved organic carbon (DOC) and microbial biomass carbon (MBC) play an important role in the ecosystem carbon cycle. In order to understand the DOC content and MBC characteristics of urban forest soils and their influencing factors, this study took the urban forest of Hefei as an example to analyze the annual dynamic characteristics and influencing factors of DOC and MBC in different vegetation types (Metasequoia, camphora, Cedrus). The results showed that the type of vegetation had a significant effect on DOC content (P <0.05). The average DOC content in 0-30 cm soil ranged from 80.35 mg · kg-1 for Cunninghamia lanceolata to 60.13 mg · kg-1 for Cunninghamia lanceolata (43.36 mg · kg-1), and generally decreased with the depth of soil layer. The contents of DOC in soil of Metasequoia glyptostroboides and cedar were higher in summer and autumn than in winter, while the content of camphorlin was the lowest in June; 0-30 The mean annual MBC of MBC in soils was in the order of (412.84 mg · kg-1)> cedar forest (358.85 mg · kg-1)> camphorlin (283.40 mg · kg-1) Soil depth increases and decreases, and summer, autumn is higher, winter is lower. Correlation analysis showed that there was a significant positive correlation (P <0.01) between the contents of DOC and MBC, DOC and MBC in soil and the contents of DOC and MBC in cedar forest (P <0.01) Secretion and decomposition of transformation is an important source of soil active carbon.