摘要
应用遥感技术可以建立光化学植被指数(Photochemical reflectance index,PRI)和光能利用效率(Lightuseef-ficiency,LUE)的关系,LUE可用来估算净初级生产力(Net primary productivity,NPP)。因而,用PRI估算植物的LUE,为估算NPP提供了新的方法,弥补了以往以经验模式通过温度和水分对最大LUE的胁迫来获取实际LUE的不足,进而可提高NPP的估算精度。研究表明:PRI和LUE在叶片、冠层和景观尺度上都有着很好的相关性,但是随着尺度的变化,很多因素会对这一关系产生干扰,如水分、氮元素含量、叶面积指数和太阳高度角等,从而削弱了PRI和LUE的关系。该文对建立PRI和LUE的关系过程中的影响因素进行了分析,并指出今后这一研究领域中可能改进的方面,主要包括526nm和545nm处的反射率对531nm处的反射率的作用机制、PRI随LUE的饱和现象、PRI和LUE关系的时间效应以及利用PRI估算LUE的尺度效应。
Remote sensing technology has provided a rapid, nondestructive method for establishing relationships between photochemical reflectance index （PRI） and photosynthetic light use efficiency （LUE） that is an important parameter for estimating net primary productivity （NPP）. Therefore, PRI opens a new era of esti- mating NPP that can overcome the shortcomings of the empirical model in obtaining LUE through information on temperature and water content. Many studies have demonstrated that a reliable relationship between PRI and LUE could be obtained at leaf, canopy and site scales. However, numerous confounding factors such as water content, leaf nitrogen concentration, leaf area index and sun zenith angle have emerged as scale changed, leading to disjunctive relationship between PRI and LUE. Thus, the functions of different factors on the relationship between PRI and LUE are important in understanding the mechanism for LUE estimation. This paper analyzes the confounding factors in establishing relationships between PR/and LUE and outlines possible improvements. Further research is needed on the different mechanism of reflectance at 526 nm and 545 nm relating to reflectance at 531 nm, the saturation problem of PRI with increase of LUE and the time and scale effects in estimating LUE with PRI.
出处
《植物生态学报》
CAS
CSCD
北大核心
2008年第3期734-740,共7页
Chinese Journal of Plant Ecology
基金
中国科学院知识创新工程重要方向项目(KZCX2-YW-313)
遥感科学国家重点实验室科研资助基金(KQ060006)
国家重点基础研究发展规划项目(2007CB714406)
