桂西北第二代杉木人工林的生物生产力

Biomass productivity of the second generation Cunninghamia lanceolata plantation in northwest of Guangxi

对广西西北部的南丹山口林场3个不同林龄(8、11、14年生)的第二代杉木人工林生物生产力进行了研究。结果表明:8、11和14年生杉木人工林的生物量分别为35.75、55.12和75.77 t/hm2,其中经济生物量(干材)分别为16.28、26.64和36.35 t/hm2,占林分生物量的45.5%以上;林分乔木层净生产力分别为4.47、5.01和5.41 t/(hm2.a);从8年生到11年生,树叶、树枝的组成比例呈现明显的下降趋势,再到14年生时呈增长趋势;而干材、干皮、根系却呈现相反的趋势。第二代杉木人工林的林下植被生物量均较少,其大小排列次序为14年生>8年生>11年生。

In order to understand the biomass productivity of the second generation Cunninghamia lanceolata plantation, the biomass productivity of a second generation Cunninghamia lanceolata plantation of three different stand ages （8-year-old, 11-year-old and 14-year-old） in Nandan Shankou Forestry Farm of Guangxi, China were studied. The results showed that the biomass of Chinese fir plantation increased with stand age. The biomass accumulations of 8-year-old, 11-year-old and 14-year-old Cunninghamia lanceolata plantation were 35.75, 55.12 and 75.77 t/（hm^2·a） respectively, including 16.28, 26.64, 36.35 t/hm^2 of economic biomass （stem）, and net stand productivity was 4.47, 5. 01 and 5.41 t/（hm^2 · a） respectively. From 8-year-old to 11-year-old, the percentage of leaves and branch decreased obviously, then increased along with growth process, but stem, bark and roots showed the opposite trend. The biomass of undergrowth vegetation in the second generation Cunninghamia lanceolata was less, and the order of the biomass of different stand ages was. 14-year-old 〉8-year-old 〉11-year-old.