Omasa Kenji, Hosoi Fumiki, Konishi Atsumi
Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657 Japan.
J Exp Bot. 2007;58(4):881-98. doi: 10.1093/jxb/erl142. Epub 2006 Oct 9.
Understanding and diagnosing plant responses to stress will benefit greatly from three-dimensional (3D) measurement and analysis of plant properties because plant responses are strongly related to their 3D structures. Light detection and ranging (lidar) has recently emerged as a powerful tool for direct 3D measurement of plant structure. Here the use of 3D lidar imaging to estimate plant properties such as canopy height, canopy structure, carbon stock, and species is demonstrated, and plant growth and shape responses are assessed by reviewing the development of lidar systems and their applications from the leaf level to canopy remote sensing. In addition, the recent creation of accurate 3D lidar images combined with natural colour, chlorophyll fluorescence, photochemical reflectance index, and leaf temperature images is demonstrated, thereby providing information on responses of pigments, photosynthesis, transpiration, stomatal opening, and shape to environmental stresses; these data can be integrated with 3D images of the plants using computer graphics techniques. Future lidar applications that provide more accurate dynamic estimation of various plant properties should improve our understanding of plant responses to stress and of interactions between plants and their environment. Moreover, combining 3D lidar with other passive and active imaging techniques will potentially improve the accuracy of airborne and satellite remote sensing, and make it possible to analyse 3D information on ecophysiological responses and levels of various substances in agricultural and ecological applications and in observations of the global biosphere.
了解和诊断植物对胁迫的反应将极大地受益于对植物特性的三维（3D）测量和分析，因为植物反应与其三维结构密切相关。激光探测与测距（lidar）最近已成为直接对植物结构进行三维测量的强大工具。本文展示了利用三维激光雷达成像估算植物特性，如冠层高度、冠层结构、碳储量和物种，并通过回顾激光雷达系统的发展及其从叶片水平到冠层遥感的应用来评估植物生长和形状反应。此外，还展示了最近将精确的三维激光雷达图像与自然颜色、叶绿素荧光、光化学反射指数和叶片温度图像相结合的成果，从而提供了关于色素、光合作用、蒸腾作用、气孔开放和形状对环境胁迫反应的信息；这些数据可以使用计算机图形技术与植物的三维图像整合。未来的激光雷达应用若能对各种植物特性进行更准确的动态估算，将有助于我们更好地理解植物对胁迫的反应以及植物与其环境之间的相互作用。此外，将三维激光雷达与其他被动和主动成像技术相结合，有望提高航空和卫星遥感的准确性，并能够在农业和生态应用以及全球生物圈观测中分析有关生态生理反应和各种物质水平的三维信息。
