大兴安岭重度火烧林地土壤生境质量综合评价

Comprehensive assessment of soil habitat quality of severely burned forest land in Greater Xing'an Mountains

以大兴安岭重度火烧林地为研究对象,选取未被火烧的林地作为对照,通过监测3年内火烧迹地和对照样地森林土壤生境因子的变化情况,对土壤生境质量进行了评价;通过计算各土壤生境因子的隶属度和权重,得到相应的土壤质量指数。结果表明:土壤质量指数可以较直观地反映林火对森林土壤的影响,火烧后基于不同土壤生境因子得到的评价结果存在差异;基于12个土壤生境因子的评价结果为火烧迹地土壤生境质量变好,并随时间逐步提高;基于7个土壤生境功能因子的评价发现火烧后土壤生境质量稍微下降,而后又呈上升趋势;基于3个土壤生境障碍因子的评价发现火烧后土壤生境质量明显下降,随后急剧上升;对于火烧后即时及长时间(3年以上)林地土壤的生境质量评价,建议选取基于土壤障碍因子的评价方法,这样可以减少土壤生境因子获取时的工作量,同时还能避免限制性因子被掩盖而过高评价火烧后的土壤生境质量。该评价结果为火烧后林地的管理和恢复工作提供了基础数据。

In this study, the changes of soil habitat factors of the severely burned forest lands and the unburned forest lands in Greater Xing＇ an Mountains were monitored for three years to assess soil habitat quality. The corresponding soil quality indices （SQI） were obtained by calculating the memberships and weight values of soil habitat factors. The results showed that, SQI could visually reflect the effect of forest fire on soil quality. However, the obtained assessment results were not consistent due to the different soil habitat factors applied. The results obtained from 12 soil habitat factors showed that the soil habitat quality of burned lands was gradually increased over time. The results obtained from 7 soil functional factors showed that the soil habitat quality decreased slight- ly after fire, and then increased over time. When 3 obstacle factors were applied, the assessment results showed that soil habitat quality decreased obviously after fire and sharply increased late. Therefore, the obstacle factors should be chosen to assess the quality of forest soil habitat suffer- ing from fire both instantly and after long time （more than 3 years）. Such assessment method could reduce the workload for obtaining information of soil habitat factors, and also avoid over- estimating the soil habitat quality of burned soil due to the hidden constraint factors. The results of this study could provide useful reference for the management and restoration of burned forest land.