Abstract: In a two-year field experiment with wheat cultivars under different application rates of fertilizer N, the wheat leaf pigment concentrations were monitored with hyper-spectral remote sensing, and quantitative monitoring models were established. The results showed that the pigment concentrations in wheat leaves increased with increasing N application rate, and differed significantly among- test cultivars. With the growth of wheat, the relative concentration of chlorophyll a+b varied more obviously than those of chlorophyll b and carotenoid (Car), and the sensitive bands of the pigments occurred mostly within visible light range, especially in red-edge district. The analyses on the relationships between eight existing vegetation indices and leaf pigment concentrations indicated that the concentrations of chlorophyll a, chlorophyll b, and chlorophyll a+b were highly correlated with red edge position, and the relationships to REP_LE were better than to REP_IG, giving the determination coefficient R² as 0.835, 0.841 and 0.840, and standard error SE as 0.264, 0.095 and 0.353, respectively. However, the R² values between Car and different spectral indices decreased significantly, and the differences among the spectrum indices were very small. The tests of the monitoring models with independent datasets indicated that REP_LE and REP_IG were the best to predict leaf pigment concentrations. The R² of chlorophyll a, chlorophyll a+b, and Car for REP_LE were 0.805, 0.744 and 0.588, with the RE being 9.0%, 9.7% and 14.6%, respectively, and the R² and RE of chlorophyll b for REP_IG were 0.632 and 18.2%, respectively. It was suggested that the red-edge parameters of hyper-spectral reflectance had stable relationships with the pigment oncentrations in wheat leaves, and especially, REP_LE could be used to reliably estimate the concentrations of leaf chlorophyll a and chlorophyll a+b.

Key words: Great Xing’an Mountains,  Larix gmelinii, soil organic carbon, carbon density, carbon sink, plantation management.