Response of Picea mongolica and Picea crassifolia Seed Germination and Seedling Growth to Drought and Salt Stress Modular Dynamics and Structure of Picea mongolica ECOLOGICAL FIELD THEORY APPLICATION TO REGENERATION OF Picea mongolica POPULATION A STUDY ON TAXONOMY OF PICEA MONGOLICA IN INNER MONGOLIA Study on Seed Plant Diversity and Flora in Baiyinaobao National Nature Reserve,Inner Mongolia Study on Intraspecific and Interspecific Competition of Piceamongolica Gradient distribution of soil N,P,and K along the distance from Picea mongolica seedlings root surface Relationship between ecological conditions and spruce growth on sandy land Structure and dynamics of Picea mongolica population on sand dune Relationship between seedling growth and dry matter production of spruce in sandy land Eco-physiological responses of Picea mongolica ecotypes to drought stress Regulative Law of Spruce Population on Sandy Land The Applicability of Various Methods in Analysis of Picea mongolica Population Spatial Distribution Pattern