Estimating Foliar Nitrogen Concentration of Heather (Calluna vulgaris) from Field and Laboratory Spectra

Abstract

Regional botanical surveys supported by field experiments suggest that atmospheric nitrogen deposition threatens the balance between species and causes loss of biodiversity within plant communities. Methods are required to monitor the nitrogen status of vegetation at a landscape scale and therefore the potential for ecological change. Remote sensing has the potential to monitor a number of plant biophysical and chemical variables, but its application to monitor the nitrogen status of native vegetation remains limited and untested. Using field spectroscopy, canopy reflectance measurements were taken from two heathland field sites and heather (Calluna vulgaris) plants grown in a greenhouse. The nitrogen concentration was determined through destructive sampling and chemical analysis. Stepwise multiple regression analysis was used to identify the wavebands most associated with nitrogen concentration and despite high variation in the selected wavebands between the three datasets, most of these wavebands were associated with nitrogen and protein absorption features within the spectral region 1,990-2,170 nm. Results highlight the potential of remote sensing as a bio-monitoring technique to estimate foliar nitrogen status in native plants.

Discrimination of common Mediterranean plant species using field spectroradiometry

“…Another important finding in this study concerning absorption features is the significant wavelength ranges in the SWIR specific for characterizing plants nitrogen content (1990-2170Kalaitzidis et al, 2008), and some of them highly correlated with protein and nitrogen absorption (1509, 1645, 1671-1800, 1727, 1733, 2084-2200, 2360-2370Mutanga et al, 2003). These wavelength ranges were among the ones chosen for the discrimination between C. villosa and G. acanthoclada, mostly by the non-parametric analysis.…”

Optical windows for head tissues in near‐infrared and short‐wave infrared regions: Approaching transcranial light applications

“…Proteins also manifest weak bands at around 1420 to 1600 and 800 to 1100 nm, which correspond to the first and second overtone of N‐H stretching, respectively . Furthermore, spectra in Figure also reveal several protein bands in SWIR region peaked at 2070 and 2230 to 2600 nm , which are correspondingly referred to N‐H and C‐H combinations . Other weak protein bands are overlapped with water and lipid bands and cannot be distinguished.…”

Qualitative and quantitative diagnosis of nitrogen nutrition of tea plants under field condition using hyperspectral imaging coupled with chemometrics

“…However, this method is unable to provide the internal characteristics of samples, such as the chemical components. Near‐infrared spectroscopy (NIRS) is a rapid and non‐destructive alternative that has been used in many plants or foods . It can describe the overtone and combination bands of CH, OH and NH groups in the spectral wavelength ranging from 780 to 2500 nm, so that most chemical compounds can be analyzed qualitatively or quantitatively.…”