呼中自然保护区多年冻土活动层厚度的影响因子分析

以大兴安岭呼中国家级自然保护区为对象,调查了该区多年冻土的活动层厚度,并利用多重对比分析和相关分析方法,对多年冻土活动层的影响因子进行了分析。结果表明,多年冻土活动层厚度与多个环境因子之间存在着复杂的关系。土壤含水量、地形条件和不同群落对于活动层厚度具有重要影响,而活动层厚度也会反作用于这些影响因子。其中,土壤表层含水量与活动层厚度呈极显著负相关(P<0.001)。地形坡度和活动层厚度呈显著正相关(P=0.006)。几乎每个样带的海拔与活动层厚度都有显著的相关性,但在整个研究区域内海拔与活动层厚度不存在相关性。这说明活动层厚度的变异仅在本研究的样带尺度上具有规律性,而这种规律性在稍大尺度上会消失。对于不同的群落活动层厚度的多重对比分析表明,群落的差异对活动层厚度也有明显的影响,其中狭叶杜香-泥炭藓群落更有利于多年冻土的保存。

Factors affecting the thickness of permafrost's active layer in Huzhong National Nature Reserve

Taking the Huzhong National Reserve in Great Hing'an Mountain as test object and by the methods of multiple comparison and correlation analysis,this paper studied the thickness of permafrost's active layer in the Reserve and related affecting factors.The results indicated that the thickness of the active layer had complicated relationships with its affecting factors.Soil moisture content,topographic condition and plant communities were the main affecting factors,while the thickness of the active layer also had counter-effects on them.The thickness of the active layer was significantly negatively correlated with surface soil moisture content(P<0.001),but positively correlated with slope gradient(P=0.006).For the relationships between active layer's thickness and altitude,no obvious correlation was observed on area scale,though the correlation existed on nearly all transects scale,suggesting that the variance of the active layer's thickness only had regularity on transect scale,but the regularity disappeared on bigger scales.The variance of plant communities also had obvious effects on the thickness of the active layer,and Ledum palustre-Sphagnum community was more helpful for the permafrost conservation.