干旱胁迫下马蹄金草坪反射光谱研究*

 通过在不同灌水处理下马蹄金草坪干旱胁迫试验,对草坪反射光谱的变化及所对应的叶片相对含水量、叶绿素含量以及草坪外观变化进行测定。结果表明:不同灌水处理下马蹄金草坪反射光谱在可见光波段呈规律性变化。随着干旱胁迫程度的加重,其光谱反射率随土壤含水量逐渐降低而依次升高,在波峰（556 nm）和波谷（679 nm）处尤为明显,蓝光(400~475 nm)和红光(580~700 nm)范围的反射光谱增加,与叶绿素含量呈正相关。在同一灌水处理中,草坪可见光范围反射光谱随干旱的加剧而增加,且与马蹄金植株叶片相对含水量呈显著负相关,与草坪叶绿素含量则呈正相关,且叶片相对含水量与反射光谱的相关性高于叶绿素含量与反射光谱的相关性,它们之间的关系可以用直线回归方程来表示。

Study on Spectral Reflectance of Dichondra Turf under Drought Stress

The spectral reflectance of dichondra (Dichondra repens Forst) turf was studies by measuring the leaf relative water content (LRWC), chlorophyll content (CC) and soil water content under different drought levels．The result indicated that on different levels of irrigation, the spectral reflectance of turf changed very regularly in the visible wave bands. With the aggravation of drought and the decrease of soil water content, the spectral reflectance of turf increased in turn, especially at the wavelengths of 556 nm and 679 nm, and it correlated with CC at the wavelengths of 400~475 nm and 580~700 nm. Under a level of irrigation, the spectral reflectance was negatively correlated with RLWC, but positively correlated with CC; and the correlation between spectral reflectance and LRWC was higher than that between spectral reflectance and CC. These correlations could be represented by linear regression equation.