Spectral Characteristics Of Warm Grassland And Alpine Meadow Vegetation With Different Utilization Patterns And Degradation Degrees

Grassland is the most important and wildly spread terrestrial ecosystem. The pattern and degree of grassland use influence grassland's growth and therefore affect the spectrum of the grassland. Measuring and analyzing the spectral data of temperate steppe and alpine meadow in different use pattern and degree is the basis of temperate steppe and alpine meadow remote sensing and monitoring. So it could provide a strong support for scientific research and protection of these two types of grasslands.In this study, we analyzed the spectral characteristics of temperate steppe and alpine meadow in different use pattern and degree, based on the spectral measurement of alpine meadow at Three River Source Region at Qinghai province in2009and temperate steppe at Inner Mongolia in2010and2011. These spectral characteristics including reflectance, first derivation of reflectance, continuum removed reflectance and vegetation indices. After the analysis, we got the following conclusion:(1) As a human cultured forage, Setaria italica enjoyed lower reflectance in red band and higher reflectance in green and near infrared band than other four vegetation which in different use pattern and there are peaks in its first derivation curve line in green band and red edge. The reflectance of enclosed Stipa grandis is higher than grazed Stipa grandis in green and near infrared band. Since the large biomass removal, cutted Leymus chinensis has the lowest reflectance at near infrared band and high reflectance at green and red bands.(2) As the increase of graze density, Stipa grandis grassland's red band absorption and near infrared band reflection are weaken and its continuum removed reflectance and vegetation indices are reducing. The reflectance of alpine meadow in near infrared band is decreased with the increase of degradation level.(3) There is angular effect of in Stipa grandis grassland's spectral data. The yield reflectance data is vary in different observation altitude and azimuth angle. In a fixed azimuth angle, reflectance measured in90°altitude angle is lower than these measured in a altitude lower than90°. In a fixed altitude angle, reflectance measured in0°(north) azimuth angle is lower than other azimuth angle. (4) In Bayinxile rangeland, Inner Mongolia, normalized difference vegetation index (NDVI) enjoyed the best prediction accuracy among the six types of vegetation indices when estimating the vegetation fractional coverage, the R2is0.56?...