多代连栽对不同发育阶段杉木人工林生产力的影响

在全国杉木中心产区的闽北林区,选择不同栽植代数、不同立地及不同发育阶段杉木人工林,进行多代连栽对不同发育阶段杉木人工林生长力影响的系统研究,结果表明:多代连栽对不同发育阶段杉木人工林生产力有较大影响。随栽植代数增加,不同发育阶段杉木林平均木生物量、林分生物量及林分净生产力均呈逐代下降趋势,表现为1代>2代>3代,其中2代16地位指数不同发育阶段杉木林林分生物量比1代下降1 45%～11 68%;3代杉木比1代下降17 44%～60 53%,比2代下降16 23%～55 31%,多代连栽导致了杉木人工林生产力的明显衰退。

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 plantation>the second generation plantation>the 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.