立地条件对麻栎人工林碳储量的影响

在江淮山地丘陵区，通过样地调查，研究了坡向和w对麻栎（Quercusacutisima）人工林系统碳密度及其空间分布的影响。结果表明：阴坡（SHS）树木碳密度显著高于阳坡（sus）（P〈0．05），Wt镕i《1低的立地（sus）树木碳密度显著高于w、高的（suss）（P〈0．05）。3种立地条件下麻栎各器官碳密度分配均为：干碳密度〉根碳密度〉枝碳密度〉叶碳密度。SUS和SHS林木分配较多的碳同化物供给树干生长，SUSS林木分配较多的碳同化物供给根系和枝的生长。凋落物碳密度在SUS和SHS之间没有显著差异（P〉0．05），而SUSS则显著低于SUS和SHS（JPl〈0．05）。整个剖面（0～50cm）土壤有机碳密度SHS显著高于SUS和SUSS（P〈O．05），SUS和SUSS之间没有显著差异（P〉0．05）。麻栎人工林系统总碳密度大小为SHS（146．9t·hm^2。）〉SUS（116．9t·hm^-2）〉SUSS（102．6t·hm^-2），SHS显著高于其他2种立地条件（P〈0．05），SUS与SUSS之间没有显著差异（P〉0．05）。3种立地条件下均为土壤碳密度〉树木碳密度〉凋落物碳密度，凋落物碳密度占林分总碳密度的比例仅为2．1％～3．6％。SUS和SHS土壤碳密度占林分总碳密度的比例低于SUSS，而树木碳密度占林分总碳密度比例则相反。由此可见，在江淮山丘区，w较低的阴坡（SHS）最有利于麻栎人工林碳储量的累积，相对于w、较高的立地（suss），较低的Wf±镕6砾1（sus）更有利于树木碳储量的增加。

Effect of site condition on carbon storage of Quercus acutissima plantations

Effect of slope aspect and stone content in soil on carbon density and spatial distribution of Quercus acutissima plantation was studied using sample plot investigation in Jianghuai hilly lands. The results show that tree carbon density at shady slope （SHS） was significantly higher than that at sunny slope （SUS） （P〈0.05）, it was higher at sunny slope with low stone content in soil （〈30%, SUS） than at sunny slope with high stone content in soi1（〉30%, SUSS） （P〈0.05）. Carbon density of different tree＇s organs in the three site conditions was in the order of stem〉root〉branch〉leaf. Trees allocated more carbon assimilates to supply stem growth at SUS and SHS, and more carbon assimilates to supply root and branch growth at SUSS. Litter carbon density was no significant differences between at SUS and at SHS （P〉0.05）, it was significantly lower at SUSS than that at SUS and SHS （P〈0.05）. Soil organic carbon density in profile （0-50 cm） at SHS was significantly higher than that at SUS and SUSS （P〈0.05）, there was no significant differences between at SUS and SUSS （P〉0.05）. The pattern of total forest system carbon density in the three site conditions was similar to soil organic carbon density, which was in the order of SHS（146.9 t-hmE）〉sus（116.9 t-hmE）〉suss（102.6 t.hm＇2）. The percentage of soil organic carbon density to total forest system carbon density was lower at SUS and SHS than that at SUSS, and more carbon stored in tree at SUS and SHS compared with SUSS. As a whole, SHS was the optimal site condition to enhance carbon storage for Q. acutissima plantation in Jianghuai hilly lands, SUS was more suitable to increase tree carbon storage compared with SUSS.