准噶尔盆地南缘绿洲-沙漠过渡带“肥岛”形成过程中土壤颗粒的分形研究  

Fractal Dimension Characteristics of Soil Particles in Oasis Desert Ecotone in Southern Edge of Junggar Basin

作　　者：任雪[1] 褚贵新[1] 王国栋[1] 乔旭[1] 宋日权[1] 王绍明[2] 

机构地区：[1]新疆生产建设兵团绿洲生态农业重点实验室/石河子大学农学院资环系,新疆石河子832000 [2]石河子大学生命科学院,新疆石河子832000

出　　处：《中国沙漠》2009年第2期298-304,共7页Journal of Desert Research

基　　金：国家"973"重大基础研究前期研究专项(2004CCA02800)资助

摘　　要：通过野外调查取样和室内分析的方法研究了准噶尔盆地南缘绿洲-沙漠过渡带不同地段的梭梭灌丛土壤不同空间位置（包括灌丛下和灌丛间）的土壤颗粒分形维数的变异特征,以及分形维数与土壤机械组成、土壤养分的关系。结果表明：①土壤颗粒分形维数与土壤沙粒含量呈极显著负相关（P〈0.01）,与土壤粉粒和粘粒含量呈极显著正相关（P〈0.01）,并与土壤养分含量中的有机质、全氮、全磷呈极显著的正相关（P〈0.01）,与可被植物吸收利用的速效形态养分碱解氮、速效钾、速效磷等的含量有极显著的正相关关系（P〈0.01）,土壤颗粒分形维数可用以表征土壤结构性状和肥力特征。②沙漠-绿洲过渡带典型空间位置的土壤粒级分布呈梯度性变化,从绿洲到沙漠1～0.25 mm的土壤颗粒体积百分比从0.4%增加到16%,而小于0.05 mm的颗粒体积百分比从76.6%减少到3.5%,土壤的粗粒组分明显增加,细粒组分明显递减,并且土壤颗粒分形维数从2.50降低到2.03。③不同粒径土粒的分布规律表现为灌丛下的粉粒、粘粒含量均大于灌丛间的,其中沙漠腹地灌丛下的表层土壤粉粒增加了1.23%,粘粒增加了0.06%;退耕还林地灌丛下土壤表层的粉粒增加了10.78%,粘粒增加了2.91%,说明梭梭灌丛能有效截获风蚀带来的微细尘埃、粘粒和粉沙,使灌丛下土壤的结构及肥力性状得以改善,形成灌丛“肥岛”。Field investigation and lab experiment were conducted to study the soil particle size fractal features at Haloxylon ammodendron shrub plots （both under the canopy of shrubs and in their interspaces） in the southern oasis desert ecotone of Junggar Basin. The relationships of soil particle fractal dimension with particle size distribution and with soil nutrient were analyzed. The results are as follows： ①Sail fractal dimension has significant negative relation with soil sand content （P〈O. 01）, significant positive relation with soil silt and clay content, （P〈0.01） ; has significant positive relation with contents of soil organic matter, total N, and total P （P〈0.01）, significant positive relation with available Alkli-N, available K, and available P （P〈0.01）, therefore the fractal dimension can indicate the characteristics of soil texture and soil fertility. ②The distribution of grain-size components of soil particles appears obvious gradient from oasis to desert： the volume percentage of particles within 1-0.25 mm increases from 0. 4% to 16%, and that of less than 0. 05 mm decreases from 76.6 % to 3.5 %, and the soil particle fractal dimension decreases from 2.50 to 2.03. ③The soil particle fractal dimension in soil under the canopy of shrubs is significantly greater than that in interspace microhabitats： in desert hinterland the topsoil silt content is increased by1.23% and soil clay content is increased by 0.06 %, even more, in crop-for-green plots the topsoil silt content is increased by 10.78% and soil clay content is increased by 2.91%. These have demonstrated the ＇The Fertile Island Effect＇ of shrubs.

关 键 词：绿洲-沙漠过渡带 土壤颗粒 分形维数 灌丛“肥岛” 

分 类 号：S154.1[农业科学—土壤学]