Response of Reflectance Spectra of Quercus aquifolioides Leaves to Different Degrees of Water Stress
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.
Quercus aquifoliodeswater stresshyperspectral remote sensingspectral indexphotochemical reflectance index
国家科技期刊平台
NSTL
万方数据
维普
