| 浑善达克沙地3种灌木土壤分形特征与养分关系 |
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| 引用本文： | 董雪,郝玉光,辛智鸣,段瑞兵,黄雅茹,李新乐,马媛,刘芳.浑善达克沙地3种灌木土壤分形特征与养分关系[J].草业学报,2020,29(6):172-181. |
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| 作者姓名： | 董雪 郝玉光 辛智鸣 段瑞兵 黄雅茹 李新乐 马媛 刘芳 |
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| 作者单位： | 中国林业科学研究院沙漠林业实验中心,内蒙古 磴口 015200 |
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| 基金项目： | “十三五”国家重点研发计划(2016YFC0500904)和国家自然科学基金项目(31600581)资助 |
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| 摘 要： | 以浑善达克沙地广泛分布的3种典型荒漠草原灌木柄扁桃、小叶锦鸡儿和狭叶锦鸡儿灌丛下土壤为研究对象,测定分析3种灌丛下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,探讨草原灌丛化后土壤分形特征与土壤肥力的关系,揭示灌丛植被在荒漠草原的生存与扩散机制。结果表明,3种典型灌丛形态结构存在差异,拦截风沙流后沉积在灌丛下的土壤粒度特征不同,其中粘粉沙体积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小叶锦鸡儿(2.346)>狭叶锦鸡儿(2.259)>柄扁桃(2.149)>裸沙地(2.057);土壤分形维数主要由粒径小于0.25 mm的粘粉沙(<0.05 mm)、极细沙(0.05~0.1 mm)和细沙(0.1~0.25 mm)体积百分含量决定,其中0.1 mm粒径是决定研究区灌丛下土壤分形维数的临界粒径,即小于该粒径的粘粉沙、极细沙含量越多,土壤分形维数越高。灌丛下土壤有机质和全氮含量与土壤分形维数存在极显著正相关关系(P<0.01);土壤有机质含量随土层深度增加而递减,全氮和全磷含量随土层波动性较强,不同物种间土壤有机质和全氮含量差异显著(P<0.05),而全磷含量差异不显著。灌丛覆盖的土壤结构和肥力均较裸沙地有明显改善,不同物种改良土壤的效果依次为小叶锦鸡儿>狭叶锦鸡儿>柄扁桃。
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| 关 键 词： | 草原灌丛化 土壤分形维数 肥岛效应 土层深度 |
| 收稿时间： | 2019-09-17 |
| 修稿时间： | 2019-11-01 |
Fractal features of soil and their relationship with soil fertility under three shrub species in Otindag sandy land |
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| DONG Xue,HAO Yu-guang,XIN Zhi-ming,DUAN Rui-bing,HUANG Ya-ru,LI Xin-le,MA Yuan,LIU Fang.Fractal features of soil and their relationship with soil fertility under three shrub species in Otindag sandy land[J].Acta Prataculturae Sinica,2020,29(6):172-181. |
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| Authors: | DONG Xue HAO Yu-guang XIN Zhi-ming DUAN Rui-bing HUANG Ya-ru LI Xin-le MA Yuan LIU Fang |
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| Institution: | Experimental Center of Desert Forestry, Chinese Academy of Forestry, Dengkou 015200, China |
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| Abstract: | Amygdalus pedunculata, Caragana microphylla and Caragana stenophylla are common, widely distributed shrubs in Otindag sandy land. This research studied the soil properties beneath these three shrub species. The vertical distributions of soil particle mechanical composition, soil volume fractal dimension and soil nutrients in the 0-60 cm soil depth were analyzed to explore the relationship between soil fractal characteristics and soil fertility after, grassland colonization by shrubs, to assist understanding of the mechanisms of spread and survival and of shrub vegetation in desert steppe. It was found that there are significant differences in the morphology of the three common shrubs, which result in different particle size characteristics of the soil deposited under the shrub through interception of the sand flow. The proportions of clay and silt content and the fractal dimension differed significantly among the different plant species (P<0.05). Soil fractal dimension also differed significantly (P<0.05), as follows: C. microphylla (2.346)>C. stenophylla (2.259)>A. pedunculata (2.149)>bare sandy (2.057). Soil fractal dimension was correlated with particle diameter and proportions of <0.25 mm particles included clay and silt (<0.05 mm), very fine sand (0.05-0.1 mm) and fine sand (0.1-0.25 mm). The 0.1 mm particle size was the critical size that determined soil fractal dimension under shrubs in this study area. The greater the proportion of particles < 0.1 mm diameter (such as the clay and silt, very fine sand), the higher soil fractal dimension was. There was significant positive correlation between soil organic matter content, soil total nitrogen content and soil fractal dimension (P<0.01). Soil organic matter content decreased with increasing soil depth, and total nitrogen and total phosphorus fluctuated with soil layer. The differences in soil organic matter and total nitrogen content among species were significant (P<0.05), but the difference in total phosphorus content was not significant. The soil structure and fertility of shrub-covered land were significantly improved compared with values for bare sand sites. The soil improvement associated with the different species ranked: C. microphylla>C. stenophylla>A. pedunculata. |
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| Keywords: | shrub encroachment soil fractal dimension fertile island effect soil depth |
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