重度火烧对大兴安岭天然林土壤有机碳和黑碳的影响

Impact of Severe Burning on Soil Organic Carbon and Black Carbon Content in Natural Forest of Daxing'an Mountains

以大兴安岭重度火烧迹地土壤为研究对象，通过对比研究，探讨重度火烧对大兴安岭天然林土壤有机碳和黑碳的影响。结果表明：对照样地和重度火烧迹地的土壤有机碳和黑碳质量分数都随土层深入而降低。与对照样地相比，重度火烧迹地0～5cm土层土壤有机碳质量分数增加了41．56％，＞5～10cm和＞10～20cm土层有机碳质量分数变化不大。0～5cm土层黑碳质量分数增加了21．37g／kg（p＜0．05），＞5～10cm和＞10～20cm土层黑碳质量分数分别增加了1．25、1．15g／kg，差异都未达显著水平。对照样地土壤黑碳与有机碳的比例在14．0％～18．1％，随土层深入表现出先升后降的趋势。重度火烧迹地土壤黑碳与有机碳的比例在17．3％～28．0％，随土层深入表现出逐渐下降的趋势。重度火烧迹地土壤黑碳在有机碳中的比例高于对照样地。2种林分土壤有机碳和黑碳的质量分数之间都呈极显著的线性关系（p＜0．01），黑碳在大兴安岭森林土壤有机碳的固定过程中起着重要的作用。

In the severe burned area of Daxing’ an Mountains, we studied the impact of severe burning on the soil organic carbon and black carbon content of natural forest.Both soil organic carbon and black carbon content decreased with deeper soil ho-rizon in unburned natural forest and severe burned area.Compared with unburned natural forest, the soil organic carbon content at 0-5 cm increased by 41.56%in severe burned area.Soil organic carbon content at 5-10 cm and 10-20 cm hori-zon had little change.Soil black carbon content at 0-5 cm increased by 21.37 g/kg （ p〈0.05） , which at 5-10 cm and 10-20 cm increased by 1.25 g/kg and 1.15 g/kg, respectively.However, the increase of soil black carbon in 5-10 cm and 10-20 cm didn’ t reach significant levels.The proportion of soil black carbon to organic carbon was in 14.0%-18.1%in unburned natural forest, and rose first then fell with soil horizon deepening.While the proportion of soil black carbon to organic car-bon in severe burned area was in 17.3%-28.0%and decreased with deeper soil horizon.The proportion of soil black car-bon to organic carbon in severe burned area was higher than that in unburned natural forest.The soil organic carbon content displayed a significant linear correlation with the soil black carbon content in both severe burned and unburned forest （ p〈0.01） , which meant soil black carbon played an important role in the immobilization of soil organic carbon in Daxing’ an Mountains forests.