准噶尔盆地西缘天然梭梭林土壤有机碳及养分的分布特征

The soil organic carbon and nutrient distributions under different coverages of natural Haloxylon ammodendron forest at the western margin of Dzungaria Basin in Xinjiang

采用现场调查取样、实验室分析的方法,研究了新疆准噶尔盆地西缘天然梭梭(Haloxylon ammodendron)林下土壤有机碳和养分的分布特征,并分析了其与梭梭盖度的关系。结果表明:(1)天然梭梭林下土壤有机碳含量与梭梭盖度正相关,盖度≥70%(密盖度)时,SOC平均含量达4.17g/kg;盖度50-69%(中盖度)时,SOC平均含量达1.94g/kg;盖度30-49%(疏盖度)时,平均为1.79g/kg,表明土壤有机碳主要来源于梭梭林;(2)密盖度的土壤全N、全P、全K以及速效N、速效P和速效K均大于中、疏两种盖度;(3)土壤有机碳含量与全N、全P、速效N、速效K均呈显著或极显著正相关;(4)在土壤垂直剖面中,上层土SOC及养分含量稍大于下层土,表明梭梭体内积累的氮、磷、钾还可以归还土壤。总体上看,林下土壤中的SOC与氮、磷、钾的分布都受控于梭梭的分布与生长状况。

By applying the method of field investigation and sampling and laboratory analysis,we studied the soil organic carbon and nutrient vertical distribution characteristics of different coverages of natural H. ammodendron forest in the western margin of Dzungaria basin,and analyzed their relationship with the H. ammodendron＇s coverage. The results showed that：（ 1） In the research area,the soil organic carbon content and coverage are related,SOC average content is 4. 17 g /kg in case of coverage ≥70%（ dense coverage）,SOC average content is 1. 94 g /kg in case of coverage is 50- 69%（ middle coverage）,SOC average content is 1. 79 g /kg in case of coverage in 30- 49%. SOC mainly originates from H. ammodendron.（ 2） The total N,total P,total K and available N,available P,available K in soil of dense coverage are all more than middle coverage and low coverage. In the soil vertical section,generally,the soil nutrient content is slightly greater than the subsoil.（ 3） The contents of soil organic carbon are all significant positive correlation with total N,total P,available N and available K.（ 4） In the vertical soil profile SOC and nutrient content in the upper are generally slightly larger than the subsoil. It shows that H. ammodendron accumulation of nitrogen,phosphorus and potassium can also returned to the soil.Overall,forests SOC and the distribution of nitrogen,phosphorus and potassium are controlled by the distribution and growth of H. ammodendron.