Growth space competition index(GSCI)and application in the individual intraspecies competition of Pinus tabulaeformis and Platycladus orientalis forests Response of soil ciliate communities to ecological restoration after the implementation of the conversion of cropland to forest and grassland program:a case study of Platycladus orientalis Forest Division of Successional Phase in The Platycladus orientalis Forest in the South Loess Plateau of the Northern shanxi Province Studies on the Population and Community Characteristics in Platycladus orientalis Forest