川滇高山栎幼树叶片反射光谱对不同程度水分胁迫的响应  

Response of Reflectance Spectra of Quercus aquifolioides Leaves to Different Degrees of Water Stress

作　　者：杜朋选[1] 孙鹏森[1] 刘世荣[2] 刘兴良[3] 

机构地区：[1]中国林业科学研究院森林生态环境与保护研究所,北京100091 [2]中国林业科学研究院 [3]四川省林业科学研究院

出　　处：《现代农业科技》2011年第15期210-213,共4页Modern Agricultural Science and Technology

基　　金：中国林业科学研究院院所基金海外人才专项(CAFYBB2008007);林业公益性行业科研专项(200804001);国家自然科学基金重大研究项目(30590383)

摘　　要：利用反射光谱探测植物的生理生态活动是定量遥感新的发展方向。通过盆栽川滇高山栎幼树,控制其植物水分胁迫程度,分别测定不同水分胁迫条件下川滇高山栎的光谱响应曲线和叶片水分指标的各自变化,并从光谱曲线中提取对水分敏感的光谱指数,分析高山栎水分胁迫下的高光谱特征的响应特点以及与光谱指数之间的关系。结果表明:在水分胁迫下川滇高山栎的光谱曲线可见光区(VIS)和近红外区(NIR)均呈现明显的趋势性变化;不同水分处理下归一化植被指数NDVI分别与相对含水量(RWC)、等效水厚度(EWT)均呈显著正相关关系,水分反射指数(WI)与含水量指标RWC、EWT分别均呈显著正相关关系,表明NDVI与WI光谱指数能够很好地预测川滇高山栎叶片水分的变化,而光化学反射指数PRI在预测水分含量方面的有效性受胁迫强度的影响,与水分指标的关系并不稳定。通过水分胁迫后以及随后进行的复水试验,川滇高山栎光谱指数的时间序列清晰显示了先下降后上升的变化特征,并且当叶片水分胁迫达到第42天时,叶片相对含水量达到最低值0.31,此时NDVI、WI、PRI分别达到最低临界值0.71、0.98、-0.15,需要立即复水,否则川滇高山栎幼树光合等生理特征无法恢复。通过比较研究在不同水分胁迫下,与川滇高山栎水分变化状况敏感的光谱指数,可为基于高光谱遥感技术监测植被水分状况提供参考。Detection of plant physiology by using hyperspectral remote sensing technique is one of the recent concerns.By potting Quercus aquifoliodes plants,a long term drought cycle and recovery process had been simulated by withholding water to potted olive plants.Physiological changes as well as spectral reflectance had been observed under varying water regimes during the course of treatment.This study aimed to determine effective spectral reflectance indices that closely track the change of leaf water content of Quercus aquifoliode.The results showed that under water stress,the spectral reflectance increased significantly in the visible region（VIS）and the near-infrared region（NIR）,normalized difference vegetation index（NDVI）was significantly correlated with relative water content（RWC）and equivalent water thickness（EWT）,respectively.Water index（WI）was also significantly correlated with relative water content（RWC）and equivalent water thickness（EWT）.Both NDVI and WI showed highly correlated with leaf water content indices.Comparatively,PRI showed weak correlations with either RWC or EWT.This study showed clear time-course of that under water stress and recovery,the spectral reflectance index（NDVI,WI,PRI）of Quercus aquifoliodes first decreased and then increased as the experiment proceeded.It need to be watered Quercus aquifoliodes when the leaves water stress lasted 42 days,or Quercus aquifoliodes photosynthetic rate and other physiological characteristics couldn＇t be restored.By comparing water-sensitive spectral index under different water stress,this study provided a theoretical basis for detecting vegetation water status based on hyperspectral remote sensing technology.

关 键 词：川滇高山栎 水分胁迫 高光谱遥感 光谱指数 光化学反射指数 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]