火干扰对大兴安岭兴安落叶松瘤囊苔草湿地生态系统碳储量的短期影响

Short-Term Effects of Fire Disturbance on Carbon Storage of Larix gmelinii-Carex schmidtii Forested Wetlands Ecosystem in Daxing'an Mountain

对比分析大兴安岭未火烧、轻度火烧与重度火烧兴安落叶松瘤囊苔草湿地的植被碳储量、凋落物碳储量及土壤碳储量,揭示火烧干扰对寒温带森林湿地生态系统碳储量的短期影响规律。结果表明:兴安落叶松瘤囊苔草湿地轻度与重度火烧样地的植被碳储量(6.35和0.26kg·m-2)较未火烧样地(7.12kg·m-2)降低了10.8%和96.3%,重度火烧使其显著降低(P<0.05);轻度与重度火烧样地的凋落物碳储量(0.23和0.15kg·m-2)较未火烧样地(0.34kg·m-2)降低了32.4%和55.9%,仅重度火烧使其显著降低(P<0.05);轻度与重度火烧样地的土壤碳储量(15.46和16.33kg·m-2)较未火烧样地(23.07kg·m-2)降低了33.0%和29.2%,二者均使其显著降低(P<0.05)且影响程度相近;轻度与重度火烧样地的生态系统碳储量(22.04和16.74kg·m-2)较未火烧样地(30.53kg·m-2)降低了27.8%和45.2%(8.49～13.79kg·m-2),但仅有重度火烧使其显著降低(P<0.05),即随着火烧干扰强度增加其影响随之增大。因此,从维持寒温带森林湿地生态系统碳汇功能考虑,应避免重度火灾造成的碳汇损失。

In this study, we investigated vegetation carbon storage, litter carbon storage and soil carbon storage of Larix gmelinii-Carex schmidtii forested wetlands ecosystem under the unburned site, lightly burned site and heavily burned site in Daxing＇an Mountain, in order to reveal the short-term effects of fire disturbance on carbon storage of forested wetlands ecosystem. Results showed that the vegetation carbon storage of heavily burned site （0.26 kg·m-2） significantly （P0.05） decreased by 96.3% than that of unburned site （7.12 kg·m-2）, but it on the lightly burned site （6.35 kg·m-2） only reduced 10.8% （P0.05）. The litter carbon storage of the lightly burned site （0.23 kg·m-2） and heavily burned site （0.15 kg·m-2） decreased respectively by 32.4% and 55.9% than that of the unburned site （0.34 kg·m-2）, but only the latter existed significant difference with unburned site （P0.05）. The soil carbon storage of the lightly burned site （15.46 kg·m-2） and heavily burned site （16.33 kg·m-2） was both significantly lower than that of the unburned site （23.07 kg·m-2） （decreased by 33.0% and 29.2%, P0.05）. The ecosystem carbon storage of the lightly burned site （22.04 kg·m-2） and heavily burned site （16.74 kg·m-2） decreased by 27.8% and 45.2% （8.49 or 13.79 kg·m-2） than that of the unburned site （30.53 kg·m-2）, but only the latter existed significant difference with the unburned site （P0.05）, and there were decreased trends with the fire disturbance intensity increased. Therefore, the heavily fire disturbance should be prevented in order to maintain or increase the carbon sink of the forested wetlands ecosystem.