关键词: 栽植代数, 杉木, 生长发育, 地力衰退

Abstract: The growth and development of different generation plantations of Chinese fir were studied through the investigation of different generation,age and site plantations.The results are as follows:successive planting results in significant growth degradation of Chinese fir plantations.Compared to the first generation plantations,D.B.H of the second generation and the third generation plantations decrease by 7.29～11.76 percent and 15.63～21.47 percent respectively.Heights of the second generation and the third generation plantations decrease by 7.89～11.76 percent and 17.76～22.35 percent respectively.Volumes of the second generation and the third generation plantations decrease by 21.02～24.61 percent and 38.70～44.18 percent respectively.Moreover,as planting generation increases,fast-growing periods of DBH and height become short,stand disintegration become intensive,proportions of middle diameter group decline,proportions of small diameter group and large diameter group increase.

Key words: Planting generation, Chinese fir, Growth and development, Soil degradation