黄土丘陵区撂荒群落土壤速效养分空间变异性研究  

Spatial heterogeneity of available soil nutrients in abandoned ole-field communities in the Loess Hilly Region

作　　者：隋媛媛[1] 杜峰[1,2] 张兴昌[1,2] 

机构地区：[1]西北农林科技大学资源与环境学院,陕西杨凌712100 [2]中国科学院水土保持与生态环境研究中心,陕西杨凌712100

出　　处：《草业学报》2011年第2期76-84,共9页Acta Prataculturae Sinica

基　　金：中国科学院"西部之光"资助项目(2007ZD02);中国博士后基金资助项目(20070411146)资助

摘　　要：采用经典统计学与地统计学相结合的方法,对黄土丘陵区5块不同撂荒年限样地速效养分在群落尺度上的空间分布特征进行了分析,结果表明,1）与黄土高原地区整体养分水平相比,撂荒样地土壤养分贫瘠,0～20和20～40 cm土层速效养分含量在群落演替中期较高,并且0～20 cm养分含量明显高于20～40 cm;2）速效养分的空间变异主要为结构性变异,撂荒6～7年样地土壤表层的速效钾和硝态氮以及撂荒25年样地20～40 cm硝态氮具有中等空间相关性,其他撂荒群落土壤0～20和20～40 cm的速效养分均具有高度空间相关性;3）随植被群落撂荒演替年限的增加,0～20 cm土层速效钾和硝态氮空间变异性在群落演替前期样地中最大,20～40 cm土层速效钾和硝态氮空间变异性分别在群落演替中期和前、中期样地中最大。0～20 cm土层速效磷和铵态氮空间变异性在群落演替中期样地中最大,20～40 cm土层速效磷和铵态氮空间变异性分别在群落演替前期和中期样地中最大。在不同撂荒年限样地中,4种速效养分具有不同空间自相关性和空间变异性,说明控制这几种养分空间分布的生态学主导过程可能有差异。Using classical statistics and geo-statistics,the spatial heterogeneity of soil available nutrients in five typical old-field communities with different abandonment ages in Loess Hilly Region were demonstrated at community scale.The results indicated that： 1） In the case of nutrient levels,old-fields in the study area are attributed by relative poor soils,0-20 and 20-40 cm available nutrients increased in middle abandonment stage of succession,nutrient content in surface soil was higher than that in sub-layer.2） The variability of available nutrients was mainly composed of structural variation.Soil available potassium and nitrate nitrogen in 0-20 cm of the 6-7 years old-field,and subsurface soil nitrate nitrogen in 20-40 cm of the 25-years old-field had intermediate spatial correlation.In other old-fields,available nutrients in surface and subsurface soil had strong spatial correlation.3） 0-20 cm available potassium and nitrate nitrogen showed the strongest spatial variability in earlier abandonment stage of succession;20-40 cm available potassium and nitrate nitrogen showed the strongest spatial variability in middle and early-middle stage of succession respectively;Spatial variability of available phosphorus and ammonium nitrogen in surface layer was strongest in middle abandonment stage of succession;Spatial variability of available phosphorus and ammonium nitrogen in subsurface layer was strongest in early-middle and middle abandonment stage of succession respectively.Regarding about the index of spatial heterogeneity,significant differences were found among the 5 old-field communities,which implies that the principal ecological processes of the four available soil nutrients are assorted.

关 键 词：黄土丘陵区 撂荒群落 速效养分 空间变异性 

分 类 号：S158.3[农业科学—土壤学] X171.4[农业科学—农业基础科学]