黄土丘陵沟壑区不同植物群落的土壤养分及其化学计量特征

目的]对黄土丘陵沟壑区不同群落土壤养分及化学计量进行研究,为该区的植被恢复提供一定的理论依据。方法]测定土壤的有机碳、全氮、全磷含量,计算C∶N,C∶P,N∶P,进行差异显著性检验。结果]研究区土壤有机碳和全氮含量属于6级,全磷含量属于4级,均为养分含量较低的级别;0—10cm土层土壤养分含量大于10—20cm土层;不同群落之间P含量差异不显著,柠条群落的C,N含量最高,铁杆蒿群落的C,N含量最低;柠条群落C∶N与其他群落(铁杆蒿群落除外)差异不显著,C∶N保持相对稳定;铁杆蒿群落和刺槐群落的C∶P较低,土壤P的有效性较高。结论]不同群落的生物量和盖度等特征不同,导致土壤养分有所差异;不同群落对土壤C,N,P的补充和吸收利用能力不同,导致化学计量特征有所不同。

Characteristics of Soil Nutrients and Stoichiometry in Different Communities in Hilly-gullied Region of Loess Plateau

Objective] The study aims to analyze the characteristics of soil nutrients and stoichiometry in different communities in hilly-gullied region of Loess Plateau,and to provide theoretical basis for vegetation restoration.Methods] Soil organic carbon,total phosphorous and total nitrogen were measured,and C∶ N,C∶P and N∶ P were calculated.Significance test was done in data analysis.Results] The contents of soil organic carbon and total nitrogen were at the 6thlevel,total phosphorous was at the 4th level.Soil nutrient contents of the study area were at a lower level.Soil nutrient contents of 0-10 cm were higher than that of 10-20 cm.The total phosphorous contents in different communities were not significant.The contents of organic carbon and total nitrogen in Caragana korshinskii dominated community were the highest,and the contents in Artemisia gmelinii dominated community were the lowest.The C∶ N in Caragana intermedia dominated community had no significant difference with other communities,except A.gmelinii dominated community.The C∶ P of A.gmelinii dominated community and Robinia pseudoacacia dominated community were lower than other communities.Conclusion] The biomass and coverage of different communities were different,and it led to the differences of soil nutrients.The supply and absorption abilities of C,N and P were different across communities,and it led to the differences of stoichiometric characteristics.