Grassland shows distinguishable seasonal patterns at different growth stage,while at a given time the growth rhythm of different grasslands diverges greatly.Those changes can be recorded in spectroscopic measurement performed at different time.Thus,remote sensing is found extremely useful for the study on grassland ecology.This letter reports the remote sensing investigation on natural grasslands including alpine dry steppe,mountainous dry steppe,paludification meadow and mountainous meadow around Qinghai l...