茶园与相邻林地土壤有机碳及基础呼吸的垂直分布特征

对茶园及相邻林地土壤基础呼吸的垂直分布特征进行了研究, 并试图寻求其与土壤有机碳(SOC)、水溶性有机碳(WSOC)、微生物生物量碳(MBC)的关系。结果表明茶园和林地土壤有机碳、土壤呼吸积累量、水溶性有机碳和微生物生物量碳均随着土壤深度的增加而减少, 且茶园均值大于林地。在0~100 cm土壤层次内, 茶园土壤质量敏感性指标(WSOC/SOC)平均值、代谢熵(qCO₂)平均值均大于林地, 微生物熵(qMBC)平均值小于林地。茶园和林地土壤基础呼吸速率与SOC、WSOC及MBC呈显着正相关, 向后筛选回归模型表明对茶园土壤基础呼吸的影响作用依次为SOC>MBC>WSOC,对林地土壤基础呼吸的影响作用则为WSOC>SOC>MBC.茶园土壤代谢作用强于林地, 但茶园有机碳库的稳定性比林地差, 不利于土壤有机碳库的积累, 为促进茶叶生产的持续健康发展, 茶园土壤需要更加科学合理的施肥和耕作措施。

Vertical Distribution of Soil Organic Carbon and Soil Basal Respiration in Tea Soil and Adjacent Woodland Soil

In this study, the vertical distributions of soil organic carbon(SOC), water soluble organic carbon(WSOC), microbial biomass carbon(MBC) and soil basal respiration(SBR) in tea soils and their adjacent woodland soils were determined to explore the relationship between soil basal respiration rate and SOC, WSOC and MBC. Results showed that SOC, WSOC, MBC and soil cumulative respiration flux were all greater in tea garden than in woodland, and decreased with increasing soil depth in both types of soils. Biological activity indicators(SWOC/SOC and qCO₂) in the tea garden soils were also greater than those in the woodland soils. However, qMBC in the tea garden was less than that in the woodland. Soil respiration rate was significantly and positively correlated with SOC, WSOC and MBC. Multiple linear regression by "Backward Elimination" method showed that soil respiration rate was affected by SOC>MBC>WSOC in the tea garden soils, but by WSOC>SOC>MBC in the woodland soils. Soil metabolism was greater in the tea garden than in the woodland soils. The stability of soil carbon pools in the tea garden was less than that in the woodland, implying less accumulation of soil organic carbon in tea garden than in woodland. More attention to scientific and reasonable fertilization and tillage management is necessary to maintain soil sustainability of tea gardens.