Canonical correlation factors causing the formation of accumulated sand-belts along the oasis fringe in Hexi corridor Paleoclimatic Analysis of Paleogene Flora in Yilan County, Heilongjiang INTRODUCTION AND PROVENANCE TRIAL OF EUCALYPTUS NITENS AND ITS POTENTIAL IN PLANTATION FORESTRY IN CHINA Relationships Between Environment and Spatial Pattern of Vegetation Types in the Mid Tianshan Mountains Research on Climate Ecological Effect Evaluation of Regional Protection Forest System in Wulanbuhe Desert