A Study on Basic Wood Property of Juvenile Population in Ussuri Poplar Physioecological characteristics of four dominant plant species in Kerqin sandy land Differential Expression of SA and H2O2 between Susceptible and Resistant Poplars Challenged by Botryosphaeria dothidea SSR of Genetic Distance and Clustering Analysis on Different Populus Section Clones Influence of Learning Experience of Parasitoid Scleroderma sichuanensis on the Parasitism of Batocera horsfieldi Larvae THE SOIL AMELIORATION EFFECT OF POPLAR-BLACK LOCUST MIXED PLANTATION ON SAND SOIL AND THE INTERACTION OF MUTUAL SUPPLEMENT OF NUTRIENT BETWEEN TREE SPECIES