武功山日本柳杉林与草甸土壤碳氮特征和pH比较

Carbon, Nitrogen and pH in Meadow Soil at Cryptomeria japonica Forests in Mt. Wugong

【目的】通过研究日本柳杉Cryptomeria japonica(L.f.)D.Don造林34年后与其山地草甸土壤碳氮特征和pH的比较,为武功山山地草甸脆弱生态系统恢复建设提供理论依据。【方法】以江西武功山山地草甸为研究对象,选择具有代表性样地,采用五点取样法,采集小区内0~20cm土层的土样,收集草甸地上凋落物,对草甸与日本柳杉林土壤凋落物碳氮指标与pH进行测定。【结果】造林会显著增加土壤全氮、铵态氮、硝态氮、有效态氮、可溶性有机氮、可溶性有机碳、微生物量碳含量、凋落物有机态碳、凋落物全氮(P<0.05),但是却显著降低土壤pH(P<0.05);土壤pH与土壤有机质碳、全氮、铵态氮、硝态氮、有效态氮、可溶性有机氮、可溶性有机碳、微生物量碳含量、凋落物有机态碳、凋落物全氮呈显著负相关(P<0.05)。【结论】日本柳杉造林对土壤微生物活性、土壤质量以及N矿化能力具有积极效应;造林可降低土壤pH值,土壤pH与有机物质分解存在紧密联系。

【Objective】 Relationship between carbon(C), nitrogen(N) and pH in meadow soil at the forests of Cryptomeria japonica(L. f.)D. Don after afforested 34 years previously in Mt. Wugong was studied to extract crucial information on the restoration and construction of the fragile ecosystem. 【Method】Samples from 0-20 cm soil layer and litter on the meadow ground were collected by 5-point sampling method at representative plots at the forests for the determinations of C-and N-indices and soil pH. 【Result】Planting of C. japonica significantly increased the total N, ammonium N, nitrate N, available N, soluble organic N, soluble organic C, and microbial biomass C in soil, as well as the organic C and total N in litter(P<0.05), but significantly reduced soil pH(P<0.05). Soil pH inversely correlated with the organic C, total N, ammonium N, nitrate N, available N, soluble organic N, soluble organic C, and microbial biomass C in soil, and the organic C in litter.【Conclusion】 C. japonica planting positively impacted the microbial activity as well as the quality and N mineralization capacity of the soil,and decreased the svil pH,which was closely related with the organic matter decomposition.