九寨沟马脑壳金矿矿山土壤养分空间分布格局

通过对九寨沟马脑壳金矿矿山南坡(海拔2 900~3 500 m)采矿、排渣(包含翻新土)边坡(简称挖、排坡)和对应同生境原生草地的土壤养分对比研究,揭示矿区土壤主要养分氮、磷、钾和土壤有机碳 (简称SOC)空间分布格局,为矿山生态恢复提供基础数据。结果表明,挖、排坡土壤养分(包括SOC和pH值)水平随海拔升高而变化小,土壤有效养分整体含量较低,有效氮、钾含量远小于对应原生草地。原生草地土壤养分随海拔、土壤层次(即深度)变化及坡脊坡谷分布具有一定的规律性:1) 各层次土壤有效氮、磷、钾随海拔的增加呈减小的趋势,随土壤深度增加逐渐减小,坡脊小于坡谷;土壤SOC随海拔的升高先降低然后升高再降低,变化起伏;2) 土壤有效氮、磷、钾含量均与SOC呈显著相关关系(P<0.05);3) 海拔、土壤深度及坡脊坡谷等环境因子对土壤有效氮、磷、钾及SOC含量的分布均有显著影响。另外,干扰对原生草地土壤养分的分布也有一定的影响。

Spatial distribution pattern of soil nutrient contents in Jiuzhaigou Manaoke Gold Mine Valley, Sichuan, China

Basic data for ecological restoration around gold mines was sought by comparing,the spatial distribution pattern of principal soil nutrient contents(including available N,P,K and organic carbon(SOC)) on the residue slope(including excavating slope and slag slope,etc.) with those in the original meadow/grassland which has the same habit of a south slope(at altitudes of 2 900 to 3 500 m) near the Jiuzhaigou Manaoke Gold Mine.Soil nutrient content of the residue slope did not differ significantly with altitude.The available nutrients were low and the averaged available N and K were far lower on the residue slope than those of the corresponding original grassland where the contents of soil available N,P and K decreased with increases in altitude and soil depth,and where the nutrients were lower at the slope-ridge than at the slope-valley.SOC in the original grassland initially decreased with increasing altitude,then increased,and finally decreased again.The correlations between contents of available N,P and K and SOC were significant in the original grassland.Environmental factors,including altitude,soil depth,ridge and valley slope,greatly influenced the distribution of soil nutrients and SOC as did soil disturbance.