Comparative study on estimation of nitrogen content in the heterogenious typical steppe using various red edge position extraction techniques

This study was conducted in the temperate typical steppe with relatively high species richness in Inner Mongolia. We extracted the red edge position from ground-based spectral data for canopy and leaf using 6 different methods, and analyzed the relationship between the red edge position extracted from canopy spectra and associated nitrogen concentration of canopy. The results showed that the red edge position substantially varied with the extraction methods, as well as the sampling sites (plant species). For nitrogen concentration estimation at the canopy scale, the linear extrapolation method had a relatively high correlation coefficient and the nitrogen concentration estimates at Stipa grandis-dominated sites were slightly better than those of the large sampling sites with multiple dominant plant species.