A brief introduction of structural equation model and its application in ecology Anatomical characteristics of leaf epidermis and vessel elements of Schisandra sphenanthera from different districts and their relationships to environmental factors APPLICATIONS OF MULTIVARIATE STATISTICAL ANALYSIS IN FORESTRY AND ITS IBM-PC SOFTWARE PACKAGES Source identification and potential ecological hazards assessment of trace metalloid/heavy metals in the soil of Tianshan Mountains, Xinjiang, China. Characteristics of partial acid hydrolysis in five plant polysaccharides Statistical analysis of data from BIOLOG method in the study of microbial ecology