海拔和坡向对伊犁河谷草地土壤理化性质的影响

Effect of Elevation and Slope Direction on Soil Physical and Chemical Properties of Grassland in Yili Valley

[目的]研究海拔和坡向对伊犁河谷草地土壤性质的影响。[方法]以新疆伊犁昭苏和察布查尔县海拔1 400~2 800 m不同剖面草地土壤为研究对象,探讨海拔和坡向对草地土壤性质的影响。[结果]南坡不同海拔全氮(0.33~3.24 g/kg)在1 400~2 000 m随海拔升高而增加,其后在2 200~2 800 m显著降低(P<0.05),硝态氮(1.43~76.33 mg/kg)、铵态氮(22.84~110.17 mg/kg)在1 400~2 800 m随海拔升高而显著降低(P<0.05),与海拔呈显著负相关(P<0.05)。北坡不同海拔全氮(0.08~1.13 g/kg)在1 400~2 800 m随海拔升高而降低。铵态氮(27.96~132.73 mg/kg)在1 400~1 800 m随海拔升高而显著增加(P<0.05),其后在2 000~2 800 m显著降低(P<0.05)。硝态氮(0.73~13.8 mg/kg)在1 400~2 800 m随海拔升高而增加。除北坡相同海拔相同土层铵态氮大于南坡外,全氮、硝态氮及其他理化性质均呈南坡大于北坡。南坡海拔与含水量、全氮呈正相关,北坡海拔与含水量、容重、硝态氮呈正相关。[结论]该研究对伊犁草原生态保护、土壤氮循环和退化生态系统恢复重建具有一定的理论意义和实践指导价值。

[Objective]To study effect of elevation and slope direction on soil properties of grassland in Ili Valley. [Method]Grassland soil samples were collected at altitudes of 1 400-2 800 m of Zhaosu and Chabuchar county,Ili,Xinjiang,were analyzed the effect of different altitude and slope to properties of gassland soil.[Result]The TN of south slope（ 0. 33-3. 24 g/kg） increased with the increasing of the altitude from 1 400 to2 000 m,and then decreased with increasing of the altitude from 2 200 to 2 800 m. Nitrate nitrogen（ 1. 43-76. 33 mg/kg） and ammonium nitrogen（ 22. 84-110. 17 mg/kg） decreased with the increasing of altitude from 1 400 m to 2 800 m,and negative correlated with elevation. The TN of north slope（ 0. 08-1. 13 g/kg） decreased with the increasing of altitude from 1 400 m to 2 800 m. Ammonium nitrogen（ 27. 96-132. 73 mg/kg） increased with increasing of altitude from 1 400 m to 1 800 m,and then decreased with increasing of altitude from 2 000 m to 2 800 m. Nitrate nitrogen of north slope（ 0. 73-13. 8 mg/kg） increased with increasing of altitude from 1400 m to 2800. Except from the ammonium nitrogen at same altitude and soil depth of north slope higher than south slope,the TN,nitrate nitrogen and other physical and chemical properties of south slope were higher than north slope. According to the correlation analysis,in south slope the elevation was positively correlated with WC and TN,in north slope the elevation was positively correlated with WC,bulk density and nitrate nitrogen. [Conclusion]The study has certain theoretical significance and practical guiding value for ecological protection,soil nitrogen cycle and restoration and reconstruction of degraded ecosystem in Yili grassland.