杉木连栽地营造的米老排人工林生物量

Biomass of Mytilaria laosensis Plantation on Site of Continuous Chinese fir( Cunninghamia lanceolata) Monoculture

在福建南平对2代杉木人工林采伐迹地上营造的22年生米老排和杉木人工林(对照)的乔木层生物量及其空间分配格局进行研究,结果表明:建立的米老排、杉木各器官相对生长模型W=a(D2H)b的决定系数均在0.9以上,拟合效果较好。22年生米老排乔木层生物量为244.39 t·hm^(-2),比杉木(对照)高68.42%,各器官生物量大小顺序为:干(54.51%)>根(21.07%)>枝(11.45%)>皮(5.79%)>叶(3.44%)>枯枝(2.89%)>花果(0.85%),均大于杉木;米老排直径大于2 cm枝的生物量比例(41.31%)远大于杉木(2.43%),但<0.5 cm枝的生物量比例(19.02%)小于杉木(26.78%);米老排人工林根系生物量为51.50 t·hm^(-2),比杉木人工林高61.39%,其83.91%的根系生物量集中在0~40 cm深度的土层中;米老排细根(直径<0.2 cm)生物量在0~10 cm表层土壤中的比例(42.35%)高于杉木(33.00%),且在40 cm以下土层生物量的分配率也大于杉木。米老排较高的细根生物量可能是其生产力高于杉木的主要原因之一。

Biomass and its distribution of a 22-year-old Mytilaria laosensis plantation on site of continuous Chinese fir （ Cunning- hamia lanceolata） monoculture was studied in Nanping, Fujian province. The results showed that coefficient of determinations of the biomass allometric equations （ W = a（D2H） b ） developed for different organs of M. laosensis and Chinese fir plantations were over O. 9 ,indicating good fitting effects. Tree layer biomass of the 22-year-old M. laosensis plantation was 244. 39 t · hm^-2, and it was 68.42% higher than that of the Chinese fir （control）. The order of different organs of the M. laosensis plantation was stem （54. 51% ） 〉 roots （21.07%） 〉 branches （ 11.45 % ） 〉 bark （ 5.79% ） 〉 leaves （ 3.44% ） 〉 dead branches （ 2. 89 % ） 〉 reproductive parts （0. 85% ）, and they were higher than those of the Chinese fir. Biomass proportion of branches with a diameter 〉 2 cm of the M. laosensis plantation （41.31%） was much higher than that of the Chinese fir （2.43%） ,but the proportion of branches with a diameter 〈0. 5 cm （ 19.02% ） was lower than that of the Chinese fir （26. 78% ）. Root biomass of the M. laosensis plantation was 51.50 t · hm^-2 ,it was 61.39% higher than that of the Chinese fir,and 83.91% of the total biomass concentrated in the 0 -40 cm soil layer. Fine root （ diameter 〈0. 2 cm） biomass proportion at the top 0 - 10 cm soil layer of the M. laosensis plantation （42. 35% ） was higher than that of the Chinese fir （33.00%）, and its proportion below 40 cm soil layer was higher than that of the Chinese fir too. Higher fine root biomass of the M. laosensis plantation may be one of the primary reasons for its higher productivity than that of the Chinese fir.