Effect of Successive Planting on Productivity of Chinese Fir of Different Age Plantations

The effect of successive planting on productivity of Chinese fir(Cunnighamia lanceolata)plantations with different ages was studied through the investigation of different generation,age and site plantations in north Fujian Province.The results were as follows:Productivity of Chinese fir plantations with different ages were influenced significantly by planting generation.As planting generation increases,the biomasses of average tree and stand and net stand productivity of plantations with different ages decrease.Their productivities were in the sequence of the first generation plantationthe second generation plantationthe third generation plantation.Compared to the first generation plantation under index site 16,the stand biomasses of the second generation and the third generation plantations decrease from 1. 45% to 11. 68%and 17. 44% to 60. 53% respectively.Stand biomass of the third generation plantation decrease from 16. 23% to 55. 31% compared to the first generation plantation.Successive planting of Chinese fir results in significant decline of site productivity.