Determination the nitrogen status of wetlands using emergent macrophytes leaf spectral reflectance

In order to revealing the influence of nitrogen (N) on wetland plants, the hyperspectral traits of reed (Phragmites australis) were measured by FieldSpec®3. There were five N treatments, including 0, 1, 2, 5, and 20 mg/L. The hyperspectral information is useful to exhibit the characteristics of spectral reflectance in reed leaves under N influence. The results showed that the chlorophyll content of reed leaves was different under different N treatments. The influence of N on the spectra of reed leaves was obvious. The red shift phenomenon could be clearly seen through the 1st derivative spectra and red age parameters. There were distinct differences between the most extreme N treatments (ON and 20N). A majority of near-infrared bands were significantly affected by N. This work provides strong evidence that hyperspectral radiometry may be employed to monitor the nitrogen status of wetlands.