Community characteristics and species diversity research of Acer ginnala in Qiliyu, Shanxi Genetic Diversity of Acer ginnala Populations at Different Elevation in Qiliyu Based on ISSR Markers Growth responses of four northern broadleaved tree species to soil Cd stress Structure and Spatial Distribution of Acer ginnala Population in Qiliyu,Shanxi Kinetics in Suspension Culture of Acer ginnala