摘要
植物根系研究对于理解全球气候变化下的碳储存与碳分配等问题具有重要意义.而探地雷达可以在不破坏土壤环境的情况下获取根系信息,但其探测效果会受到土壤环境、根的大小及其空间分布等因素的影响.因此,探地雷达在野外自然条件下对根系的识别率和识别精度仍需进一步分析验证.本文基于对内蒙古灌丛化草地小叶锦鸡儿灌木根系的探测实验,设计雷达测量结果与剖面开挖实测结果的匹配比较方案.进一步探究天线频率、根的直径、根的深度、根的含水量以及根的伸展角度对探地雷达探测根系的识别率和识别精度的影响.结果表明:(1)三种天线频率对小叶锦鸡儿根系的识别率均可达50%以上,其中900 MHz频率天线的识别率最高,可达56%;(2)根的四种因素对识别率的影响程度不同,其中根的直径影响最大,其次是根的深度,根的含水量和伸展角度影响较小;(3)符合探地雷达探测和识别条件的根占总的根样本数的60%以上,有利于探地雷达用于大面积内根的平均数量和分布的估计.研究结果可以为探地雷达应用于野外根系无损性探测研究提供参考.
Plant roots determines water nutrient uptake, carbon uptake and allocation, and represent an important role in terrestrial ecosystems.Study of roots lags far behind above ground due to invisibility. Ground-penetrating radar is a non-invasive method of observing roots, but it is affected by some factors such as the soil environment, roots size, water content and their spatial distribution. Therefore, the recognition rate and accuracy of GPR on roots under natural conditions in situ need to be analyzed and verified. We conducted a GPR detection experiment on the roots of a dominant shrub, Caragana microphylla, in Inner Mongolia grassland, and tested the GPR detection results by profile excavation. The effects of the antenna frequencies, root diameter, root depth, root water content and root extension angle on the GPR detection were further investigated. The results indicated that:(1) all three antenna frequencies(1600 MHz, 900 MHz, 400 MHz) have a recognition rate of more than 50%, with the 900 MHz antenna having the highest recognition rate of 56%;(2) the four factors about roots have different degrees of influences on the recognition rate of roots, with the root diameter having the greatest influence, followed by the root depth, and relatively less influence of the root water content and extension angle;(3) the roots that meet the conditions for GPR detection and recognition account for more than 60% of the total root samples, which is conducive to the use of GPR for the estimation of the average number and distribution of roots over a large area. This study can provide a reference for the application of GPR for non-destructive roots detection in the field.
作者
张璐云
崔喜红
全振先
张政
陈晋
ZHANG LuYun;CUI XiHong;QUAN ZhenXian;ZHANG Zheng;CHEN Jin(Institute of Remote Sensing Science and Engineering,Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China;Beijing Engineering Research Center for Global Land Remote Sensing Products,Faculty of Geographical Science,Beijing 100875,China;State Key Laboratory of Earth Surface Processes and Resource Ecology,Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China)
出处
《地球物理学进展》
CSCD
北大核心
2021年第6期2764-2774,共11页
Progress in Geophysics
基金
国家自然科学基金面上项目(41571404)资助。
关键词
探地雷达
植物根系
无损探测
目标识别
Ground penetrating radar
Plant root system
Non-destructive detection
Object recognition
