老龄杉木人工林生态系统碳库及分配

对福建省南平市安曹下87年生的杉木人工林碳库及其分配进行研究．采用分层切割法和相对生长方程计算乔木层生物量，样方收获法测定林下植被生物量、枯枝落叶层和粗木质残体现存量，CN元素分析仪测定碳含量，研究结果表明：老龄杉木人工林生态系统碳库为287.89t·hm^-2，其中乔木层碳库占生态系统碳库的68.18％，矿质土壤层碳库占26.39％，而林下植被层、枯枝落叶层和粗木质残体碳库所占比例之和不超过6％。老龄杉木林的干材（干＋皮）碳库占乔木层碳库的79．61%。87年生与40年生杉木人工林碳库很接近，前者比后者仅高出7．15％，主要是因为两者占生态系统主体的乔木层碳库和土壤层碳库很接近，前者分别仅高出后者的4．51％和10．39％，前者林下植被层和粗木质残体碳库较大，分别是后者的2．05倍和2．80倍，而枯枝落叶层碳库则低于后者。因此，老龄阶段杉木人工林生态系统碳库增幅不大，但在碳库分配上变化明显。

Carbon Storage and Allocation in Old-Growth Cunninghamia lanceolata Plantation in Subtropical China

The carbon storage and its allocation of an 87-year-old Cunninghamia lanceolata plantation in Nanping, Fujian province was studied. The methods of allometric dimension analysis and sampling harvest were used to estimate the biomass of tree, shrub and herbage layers, respectively. Carbon concentrations of plant and soil samples were determined using an ELEMENTAR Vario EL Ⅲ CN Analyzer. The result showed that total carbon storage in the plantation was 287.89 t·hm^-2, of which the tree layer accounted for 68.18% and the mineral soil for 26.39%, while the total of the undergrowth, litter layer and coarse woody debris （CWD） occupied no more than 6%. In the allocation of tree carbon pool to various organs,stem and bark accounted for 79.61%. Carbon storage in 87-year-old Cunninghamia lanceolata plantation ecosystem is only 7. 15 %0 higher than that in 40-year-old Cunninghamia lanceolata plantation ecosystem, which may be due to similar tree layer and mineral soil carbon storages in the two plantations. The old-growth plantation had only 4. 51% and 10.39% higher tree layer and mineral soil carbon storages than 40-year-old plantation respectively. Carbon storages of understory and CWD in the old-growth plantation were 2.05 and 2.80 times as much as that of 40-year-old plantation, whereas carbon storage of litter was lower in the old-growth plantation.In conclusion, carbon storage of old-growth Cunninghamia lanceolata plantation increased a little, but its allocation changed significantly.