Longitude gradient changes on plant community and soil stoichiometry characteristics of grassland in Hulunbeir New advances in seed geography Spatial changes and influencing factors of fine root carbon, nitrogen and phosphorus stoichiometry of plants in China Study on the Relationships between Longitude and Radial Sound Vibration Parameters of Genus Picea Growth Period of Spring-Sowing Wheat on different Locations STUDY ON THE GEOGRAPHIC ELEMENTS AFFECTING TEMPERATURE DISTRIBUTION IN CHINA INTRODUCTION TO THE FLORA OF GUANGXI Stand Factors of Picea schrenkiana var. tianschanica alongthe Altitudinal Gradient in Different Longitudes