Application of 3S Technologies(Remote Sensing,Geographical Information System, and Global Positioning System)to Assess the Resources and Ecology of the Grassland of Xianghuang Banner, Inner Mongolia Application of RS, GIS and GPS Techniques in Study of Avian Habitat Application of "3S" technologies in continuous usage of traditional Chinese medicine resources Monitoring grassland rodents with 3S technologies 3S technologies and their application in ecological research