桂西南28年生米老排人工林生物量及其分配特征

应用相对生长法对桂西南28年生米老排人工林生物量及其分配特征进行了研究。结果表明:28年生米老排人工林生物量为281.47t·hm-2,生态系统生物量分配格局为乔木层(97.89%)>凋落物层(1.87%)>灌木层(0.16%)>草本层(0.08%);其中,乔木层生物量为275.54t·hm-2,其生物量在各器官的分配规律为树干(63.01%)>树根(21.01%)>树枝(9.64%)>树皮(4.38%)>树叶(1.72%)>果实(0.25%);乔木生物量的径级分布接近正态分布,生物量主要集中在径级为25～29cm的林木,占乔木层生物量总量的48.15%;28年生米老排人工林林分年均净生产力为15.61t·hm-2·a-1,各组分净生产力大小顺序为乔木层(81.50%)>凋落物层(16.82%)>灌木层(0.98%)>草本层(0.70%);乔木层年均净生产力为12.72t·hm-2·a-1,各器官净生产力大小顺序为树干(48.76%)>树叶(18.64%)>树根(16.26%)>树枝(7.46%)>果实(5.50%)>树皮(3.39%)。

Biomass and its allocation in a 28-year-old Mytilaria laosensis plantation in southwest Guangxi

By the methods of plot sampling and allometric dimension, this paper studied the biomass and its allocation in a 28-year-old Mytilaria laosensis plantation in southwest Guangxi. The biomass in the plantation was 281.47 t·hm-2, and the biomass allocation was in the order of tree layer (97.89%) > litter layer (1.87%) > shrub layer (0.16%) > herb layer (0.08%). The biomass in the tree layer was 275.54 t·hm-2, and the biomass allocation was in the sequence of stem (63.01%) > root (21.01%) > branch (9.64%) > bark (4.38%) > leaf (1.72%) > fruit (0.25%). The biomass of the trees with different diameter at breast height (DBH) was approximately in normal distribution, and that of the trees with 25-29 cm DBH accounted for 48.15% of the total. The mean annual net productivity of the plantation was 15.61 t·hm-2·a-1, and the net productivity of different components of the plantation was tree layer (81.50%) > litter layer (16.82%) > shrub layer (0.98%) > herb layer (0.70%). The mean annual net productivity of the tree layer was 12.72 t·hm-2·a-1, and the relative proportion of different tree organs was stem (48.76%) > leaf (18.64%) > root (16.26%) > branch (7.46%) > fruit (5.50%) > bark (3.39%).