【摘要】 选择三江平原湿地分别垦殖为旱田和水田以及人工林3种利用方式,调查土壤理化性质及团聚体组成的变化。结果表明:不同利用方式下土壤理化性质发生了明显变化。与湿地相比,不同利用方式下土壤水分含量显著降低,而土壤容重显著增加,并且除水田土壤速效磷含量较湿地土壤有所增加外,其他利用方式下全氮、全磷、碱解氮和速效磷含量均有不同程度的降低,特别是旱田和人工林利用方式下的降低幅度明显大于水田;不同利用方式下土壤脲酶、蔗糖酶和过氧化氢酶活性均明显低于湿地,水田利用方式下土壤脲酶、蔗糖酶和过氧化氢酶活性降低幅度明显小于旱田和人工林;除水田利用方式下土壤酸性磷酸酶活性较湿地有所降低外,旱田和人工林利用方式下土壤酸性磷酸酶活性较湿地无显著变化;不同利用方式下土壤总有机碳、微生物量碳、水溶性碳和易氧化碳含量均较湿地有不同程度的降低,除易氧化碳含量外,旱田和人工林利用方式下土壤总有机碳、微生物量碳和水溶性碳含量的降低幅度均显著大于水田;不同利用方式下土壤机械稳定性团聚体组成也发生了明显的变化,水田和旱田利用方式下土壤平均重量直径(MWD)较湿地均有所降低,特别是旱田土壤MWD降低幅度更为明显,但人工林土壤MWD却较湿地有所增加;不同利用方式会显著影响土壤理化性质及土壤团聚体组成,其中水田利用方式对土壤理化性质、有机碳稳定性和土壤团聚体破坏程度明显低于旱田和人工林;而人工林由于受人为扰动较小,对土壤理化性质及结构的影响程度明显小于旱田。更多还原

【Abstract】 The aim of this study to clarify the effects of three land use types reclaimed from wetlands in Sanjiang Plain( upland,paddy field and artificial forest) on soil physicochemical properties and aggregate composition. The results showed that soil physicochemical properties significantly differed among different land use types. Compared with wetland,the three land use types significantly decreased soil water content and increased soil bulk density. Compared with wetland soil,soil available P in paddy field increased,while total N,total P,alkali-hydrolyzable N and available P reduced in other land use types. There was a significantly higher reduction in upland and artificial forest than that in paddy field. The activities of soil urease,invertase and catalase under different land use types were significantly lower than those of wetland,with the reduction in paddy fields being significantly lower than that in upland and artificial forest. The activity of soil acid phosphatase in upland and artificial forest showed no significant different with wetland soil,whereas that in paddy field was lower. In addition,the concentrations of total organic C( TOC),microbial biomass C( MBC),dissolved organic C( DOC) and readily oxidized C( ROC) in soil under different land use types was lower than that in wetland soil. The decrease in TOC,MBC,DOC and ROC content was significantly higher in upland and artificial forest than that in paddy field. The soil aggregate composition with mechanical stability changed obviously under different land use types. The mean weight diameter( MWD) of soil in paddy field and upland was lower than that in wetland,with a significant decrease in uplands. However,soil MWD of artificial forest significantly increased compared to wetland. Our results indicated that the different land use types reclaimed from wetland significantly changed the soil physicochemical properties and aggregate composition. The damages of soil physicochemical properties,organic C stability and soil aggregate in paddy field were significantly lower than those in upland and artificial forest. Moreover,the destruction of soil physicochemical properties and structure in artificial forest was significantly lower than that in upland due to limited disturbance.更多还原