基于主成分分析的青藏高原多年冻土区高寒草地土壤质量评价  

Soil quality assessment of alpine grassland in permafrost regions of Tibetan Plateau based on principal component analysis

作　　者：刘鑫[1] 王一博[1,2] 吕明侠 孙岩 杨文静[1] 赵金鹏 LIU Xin;WANG Yibo;LU Mingxia;SUN Yan;YANG Wenjing;ZHAO Jinpeng(College of Earth and Environment Science,Lanzhou University,Lanzhou 730000,China;State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;Hydrology and Water Resources Survey Bureau in Dingxi,Dingxi 743000,Gansu,China)

机构地区：[1]兰州大学资源环境学院,甘肃兰州730000 [2]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000 [3]甘肃省定西水文水资源勘测局,甘肃定西743000

出　　处：《冰川冻土》2018年第3期469-479,共11页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金重点项目(91547203;41530752);国家自然科学基金面上项目(41671015)资助;冻土工程国家重点实验室开放基金项目(SKLFSE201501)

摘　　要：土壤质量评价是提高对土壤质量理解的关键环节。为了了解青藏高原多年冻土区高寒草地土壤质量的基本情况,在青藏高原腹地西大滩至安多地区,根据不同海拔梯度和植被盖度共采集了154个土壤样品。通过主成分分析(PCA)法确定了影响青藏高原多年冻土区高寒草地土壤质量的最小数据集(MDS):全氮、全磷、全钾。根据影响土壤质量的最小数据集对青藏高原多年冻土区高寒草地土壤质量进行评价,得出了不同海拔、不同植被盖度下的土壤质量指数(SQI)。通过对不同海拔、不同植被盖度的土壤质量指数进行对比研究表明:随着海拔的升高,SQI呈增加的趋势,即海拔4 300~4 600 m(0.270±0.043)<海拔4 600~4 900 m(0.326±0.061)<海拔4 900~5 200 m(0.410±0.075);随着植被盖度的增加,SQI也呈现增加的变化趋势,即植被盖度小于50%(0.262~0.265)<植被盖度大于50%(0.336~0.344)。在分别考虑了有机质、盐分、土壤水分对土壤质量的影响下得出的土壤质量指数值与基于最小数据集得到的土壤质量指数相一致,说明基于主成分分析的最小数据集可以对青藏高原多年冻土区高寒草地土壤质量做出较准确的评价。Soil quality assessment is a key step for comprehending soil quality. In order to understand the soil quality of the alpine grassland in permafrost regions of the Tibetan Plateau,154 soil samples were collected from different altitudes and different vegetation coverages from Xidatan to Anduo in the hinterland of the Plateau.Principal component analysis（PCA） was employed to determine the minimum data set（MDS） ： total nitrogen,total phosphorus and total potassium,which affected the soil quality on the Plateau. The soil quality of alpine grassland in permafrost region of the Tibetan Plateau was evaluated according to the MDS of soil quality,and the soil quality index（SQI） was obtained under different altitudes and vegetation coverages. The comparative study of the soil quality index under different vegetation coverages and different altitudes showed that SQI increases with increase of vegetation coverage,that is to say,SQI in altitude range of 4 300 ~ 4 600 m（0. 270 ± 0. 043） 〈SQI in altitude range of 4 600 ~ 4 900 m（0. 326 ± 0. 061） 〈SQI in altitude range of 4 900 ~ 5 200 m（0. 410 ±0. 075）; with increase of vegetation coverage,SQI presents an increasing trend also,i. e.,SQI of vegetation coverage less than 50%（0. 262 ~ 0. 265） SQI of vegetation coverage more than 50%（0. 336 ~ 0. 344）. The obtained SQI value,which respectively considers the influence of organic matter,salinity and soil moisture on soil quality,is consistent with the soil quality index derived from minimum data set,which indicates that MDS based on PCA can make a more accurate assessment of soil quality of alpine grassland in permafrost regions of the Tibetan Plateau.

关 键 词：青藏高原 土壤质量 主成分分析 最小数据集 

分 类 号：S158[农业科学—土壤学]