长期排水造林对云贵高原亚热带泥炭藓沼泽土壤理化性质的影响

Effects of Long-Term Drainage for Afforestation on Soil Physicochemical Properties of Subtropical Sphagnum Mire in Yunnan-Guizhou Plateau

探究排水造林对亚热带泥炭藓沼泽土壤理化性质的影响,为科学保护与恢复该类型湿地提供理论基础。选择贵州娘娘山湿地天然泥炭藓沼泽为对照样地,选择经立地条件相似的泥炭藓沼泽排水造林20年形成的柳杉林为处理样地,比较二者表层(0~10cm)土壤理化性质的差异。主要结果:1)泥炭藓沼泽土壤总碳含量、总氮含量、pH、碳与磷质量比(C∶P)、氮与磷质量比(N∶P)、速效钾含量、硝态氮含量、铵态氮含量、土壤质量含水量显著高于柳杉林土壤相应的指标值(P<0.05);泥炭藓沼泽土壤容重显著低于柳杉林土壤容重;2)主成分分析显示,长期营造柳杉林后土壤理化性质总体已发生明显分异;3)土壤总碳含量与总氮含量呈极显著正相关(P<0.01),且二者与C∶P,N∶P,速效钾含量、硝态氮含量、质量含水量呈极显著正相关(P<0.01),与土壤容重呈极显著负相关(P<0.01),C∶P,N∶P,铵态氮含量、硝态氮含量、速效钾含量两两之间呈极显著正相关(P<0.01)或显著正相关(P<0.05);土壤质量含水量与容重呈极显著负相关(P<0.01)。总之,泥炭藓沼泽长期营造柳杉林后,表层土壤大量有机质发生氧化分解,土壤含水量显著降低,容重显著增加,土壤磷限制缓解,土壤理化性质总体发生明显分异,由泥炭土转变为矿质土。

The effects of drainage and afforestation on the physical and chemical properties of soil in subtropical Sphagnum mire were explored to provide a theoretical basis for scientific protection and restoration of this type of wetland.Natural Sphagnum mire in Niangniang Mountain wetland,Guizhou was selected as the control site,and Cryptomeria fortunei forest formed by drainage for afforestation in the sphagnum mire with similar site conditions for 20 years was selected as the treatment site,and the differences in the physical and chemical properties of the surface(0~10cm)soil between the two kinds of sites were compared.Main results:1)The total soil carbon content,total nitrogen content,pH,mass ratio of carbon to phosphorus(C∶P),mass ratio of nitrogen to phosphorus(N∶P),available potassium content,nitrate nitrogen content,ammonium nitrogen content and soil mass water content of the Sphagnum mire were significantly higher than the corresponding index values of the Cryptomeria fortunei forest(P<0.05).The soil bulk density of Sphagnum mire was significantly lower than that of the Cryptomeria fortunei forest.2)PCA showed that the overall physical and chemical properties of the soil had changed significantly after the long-term afforestation of Cryphieria fortunea forest.3)Total soil carbon content was significantly positively correlated with total nitrogen content(P<0.01),and both of them were significantly positively correlated with C∶P,N∶P,available potassium content,nitrate nitrogen content,mass water content,respectively(P<0.01),and significantly negatively correlated with bulk density(P<0.01).C∶P,N∶P,ammonium nitrogen content,nitrate nitrogen content and available potassium content were very significantly or significantly positively correlated with each other.Mass water content was negatively correlated with bulk density(P<0.01).In conclusion,after a long-term afforestation of Cryptomeria fortuneana forest in Sphagnum mire,a large amount of organic matter in the surface soil oxidized and decomposed,soil water content decreased significantly,bulk density increased significantly,soil phosphorus limitation was relieved,and the soil physical and chemical properties were significantly different overall,and the peat soil was transformed into mineral soil.