西鄂尔多斯荒漠灌丛土壤粒径分形特征与养分的耦合关系  

Fractal features of soil and their relationship with soil nutrients under desert shrubs in the West Ordos region

作　　者：董雪[1] 迟悦春 许德浩 郝玉光[1] 段瑞兵 张帅 黄雅茹[1] 孙非[1] DONG Xue;CHI Yuechun;XU Dehao;HAO Yuguang;DUAN Ruibing;ZHANG Shuai;HUANG Yaru;SUN Fei(Experimental Center of Desert Forestry,Chinese Academy of Forestry,Dengkou 015200,Inner Mongolia,China;Forestry and Grassland Bureau of Ordos,Erdos 017001,Inner Mongolia,China;Yellow River Engineering Administration of Inner Mongolia,Dengkou 015200,Inner Mongolia,China)

机构地区：[1]中国林业科学研究院沙漠林业实验中心,内蒙古磴口015200 [2]鄂尔多斯市林业和草原局,内蒙古鄂尔多斯017001 [3]内蒙古黄河工程管理局,内蒙古磴口015200

出　　处：《草业科学》2020年第12期2403-2413,共11页Pratacultural Science

基　　金：中央级公益性科研院所基本科研业务费专项资金(CAFYBB2018QA007);“十三五”国家重点研发计划(2016YFC0500904);科技基础资源调查专项(2019FY102002)。

摘　　要：植物适宜的生长和发育需要理想的土壤机械组成与养分保障,土壤分形维数和养分的分布特征及其关系对研究土壤结构的稳定性、抗风蚀性和水肥运动有着重要的作用。四合木(Tetraena mongolica)、沙冬青(Ammopiptanthus mongolicus)和霸王(Zygophyllum xanthoxylum)作为西鄂尔多斯地区广泛分布的3种孑遗濒危荒漠灌木物种,既是重要的自然资源,也是天然的生态屏障,对保障荒漠草原生态系统稳定安全具有重要意义。本研究通过测定分析3种灌丛0–60 cm土层深度的土壤颗粒机械组成、土壤体积分形维数和土壤养分含量的垂直分布特征,探讨荒漠草原土壤分形特征与土壤养分的关系,揭示灌丛植被生存与扩散机制。结果表明,3种典型灌丛拦截风沙流后沉积在灌丛土壤粒度特征不同,其中粘粉沙、极细沙体积百分含量和分形维数在不同物种间差异显著(P<0.05),土壤分形维数表现为四合木(2.432±0.041)>沙冬青(2.391±0.046)>霸王(2.276±0.034)>裸沙地(2.218±0.059);土壤分形维数主要由粒径小于0.5 mm的粘粉沙(<0.05 mm)、极细沙(0.05~0.1 mm)、细沙(0.1~0.25 mm)和中沙(0.25~0.5 mm)体积百分含量决定,其中0.1 mm作为临界粒径可以决定研究区灌丛下土壤分形维数的大小,小于该粒径的粘粉沙、极细沙含量越多,土壤分形维数越高。土壤速效钾含量随土层深度增加而递减,土壤有机质、碱解氮和速效磷随土层波动性较强,不同物种间土壤养分含量差异显著(P<0.05)。灌丛覆盖的土壤结构和养分含量均较裸沙地有明显改善。灌丛下土壤有机质和碱解氮含量与土壤分形维数存在极显著正相关关系(P<0.01),速效磷和速效钾含量与土壤分形维数存在显著正相关关系(P<0.05)。利用土壤分形维数可较好地描述西鄂尔多斯荒漠草原区风沙土性质,并且适生灌丛四合木和沙冬青可较好地改善土壤颗粒及养分特征,遏制表层风沙土的持Survival and adequate growth of plants require ideal soil mechanical composition and nutrient conditions.The fractal dimension of soil and the distribution characteristics of nutrients and their relationships play an important role for the stability of soil structure,resistance to wind erosion,and movement of water and fertilizer.Ammopiptanthus mongolicus,Tetraena mongolica Maxim,and Zygophyllum xanthoxylum Bunge are typical shrubs that are widely distributed in the West Ordos region.They are important natural resources and natural ecological barriers which are crucial for the stability of arid steppe ecosystems.In this study,we examined soils under three shrubs.The vertical distribution of soil particle mechanical composition,soil volume fractal dimension,and soil nutrients in 0–60 cm soil depth were analyzed to explore the relationships between soil fractal characteristics and soil fertility and to reveal the mechanisms of survival and diffusion of shrub vegetation in an arid steppe.The results showed significant differences in the morphologies of the three typical shrubs,which resulted in different grain size characteristics of the soil underneath the shrubs after intercepting the sand flow.The volume of clay and silt content and fractal dimension differed significantly among shrub species(P<0.05).The soil fractal dimension was significantly different(P<0.05),i.e.,T.mongolica(2.432±0.041)>A.mongolicus(2.391±0.046)>Z.xanthoxylum(2.276±0.034)>bare sand(2.218±0.059).The soil fractal dimension was correlated with<0.5 mm particles such as clay and silt(<0.05 mm),very fine sand(0.05~0.1 mm),fine sand(0.1~0.25 mm),and medium sand(0.25~0.5 mm).The 0.1 mm particle size was the critical size determining the soil fractal dimension under shrubs in the study area.The soil fractal dimension increased with increasing<0.1 mm diameter content(such as content of clay,silt,and very fine sand).Soil rapidly available potassium content decreased with increasing soil depth,and soil organic matter,available nitrogen,and availab

关 键 词：荒漠灌丛 土壤分形维数 土壤养分 垂直空间异质性 土壤颗粒 粒径分布 西鄂尔多斯 

分 类 号：S152[农业科学—土壤学]