基于GPR的陕北黄土区河北杨粗根分布特征研究  

Research on the Distribution Characteristics of Coarse Roots of Populus hopeiensis in the Loess Area of Northern Shaanxi Based on GPR

作　　者：周广行 朱清科[1] 任正龑 霍云梅 马欢[1] 王丽娜[1] 

机构地区：[1]北京林业大学水土保持学院,北京100083

出　　处：《水土保持学报》2016年第2期346-351,共6页Journal of Soil and Water Conservation

基　　金：国家科技支撑计划课题项目"困难立地植被恢复技术研究与示范"(2015BAD07B02)

摘　　要：为了探索河北杨粗根的成林过程及其水土保持功能,借助探地雷达（GPR）无损观测树木粗根技术,探测研究了陕北黄土区不同立地条件下河北杨粗根的分布特征。结果表明：（1）河北杨粗根主要集中于10—50cm土层范围内,随着土壤深度的增加,粗根密度先增大后减小,呈现二次抛物线变化趋势。不同径级粗根的分布情况为：在0—50cm土层范围内,0.5~1.5cm径级粗根所占比例最高;在50—70cm土层范围内,1.5~2.5cm径级粗根所占比例最高;在整个根系分布土层内,〉2.5cm径级粗根所占比例一直都最小,且比例都〈10%。（2）随着距树干距离的增加,粗根密度呈现幂函数递减变化趋势。不同径级粗根变化情况为：0.5~1.5cm径级粗根密度所占比例先下降后增加,而1.5~2.5cm和〉2.5cm径级粗根密度所占比例均呈现出先增加后减少的变化趋势,其中0.5~1.5cm径级粗根密度的增加在一定程度上是由1.5~2.5cm径级粗根的分生作用导致。（3）通过对地形因子进行主成分分析及双因素分析得出,坡向对粗根密度影响较大。河北杨的粗根密度在不同坡向间存在显著差异（P〈0.05）,大小排序为阴坡〉半阴坡〉半阳坡,说明土壤水分有助于提高河北杨粗根密度。在不同径级根系间,坡向对1.5~2.5cm径级粗根密度的影响相对其他径级要小。综上可见,河北杨粗根分布特征与其根系分生特性有关,同时受到以坡向为主的地形因子的影响。In order to explore the formation of natural Populus hopeiensis forest and its function of soil and water conservation, the distribution characteristics of coarse roots of Populous hopeiensis were studied under different site conditions in the loess area of northern Shaanxi based on a non-destructive method： ground- penetrating radar （GPR）. The results showed that： （1） Coarse roots of Populus hopeiensis mainly concentrated in the range of 10--50 cm soil depth. The density of coarse roots increased at first and then decreased with the increase of soil depth, presenting the trend of second parabolic curve. The distributions of different diameter class of coarse roots were listed as follows： the proportion of 0.5 to 1.5 cm diameter coarse roots was the highest in 0-50 cm soil layer. The proportion of 1.5 to 2.5 cm diameter coarse roots was the highest in 50 70 cm soil layer. And the proportion of 〉2.5 cm diameter coarse roots in the root distribution was always minimal, which was less than 10%. （2） The coarse root density showed a decreasing trend of power function with the increase of the distance from the tree trunk. The distributions of different diameter class of coarse roots were listed as follows, the proportion of 0.5 to 1.5 cm diameter coarse roots decreased at first and then increased, while the proportion of 1.5 to 2.5 cm and 〉2.5 cm diameter coarse roots increased at first and then decreased. The increasing trend of 0.5 to 1.5 cm diameter coarse root density was caused by the split of the 1.5 to 2.5 cm diameter coarse roots to a certain extent. （3） Through the principal component analysis and double factor analysis of topographic factors, slope factors had the maximal influence on the coarse root density of Populus hopeiensis. The coarse root density on different slopes had significant differences （P〈0.05） and the size order was shady slope〉semi shady slope〉 semi sunny slope, showing that the soil moisture helped toimprove the coarse coarse root density different diamet

关 键 词：探地雷达 陕北黄土区 粗根密度 分布特征 地形因素 

分 类 号：S792.11[农业科学—林木遗传育种]