受气候变暖和人为活动的共同影响,过去数十年来兴安岭山区的多年冻土退化显著。冻土退化南部快于北部、城镇快于田野、农田快于林区、采伐过林区快于原始林区。在局部小范围内,冻土退化顺序为先高后低、先山上后谷地(或盆地中心)、先阳坡后阴坡。冻土退化程序从农田(或裸地)→草地→灌丛→林地→沼泽湿地,依次冻土退化由快到慢。纬度和高度地带性控制冻土退化特征,但局地因素亦对其产生重要影响,造成小范围内冻土特征的突变。人为活动已经、正在并将对兴安岭冻土退化和寒区生态环境产生重要影响。
Due to the combined influences of climate warming and anthropogenic activities, permafrost degradation has accelerated during the last decades. Permafrost has been degrading more rapidly in the southern parts and urbanized areas, and in the cultivated and felled or cleared woodlands than in the northern parts, countryside, forested areas, and primeval forests. Permafrost degrades sooner at higher elevation, on the mountains, and on sunny slopes than at lower elevation, in the valleys and on the shadowy slopes. Permafrost degrades more readily and more rapidly in the following order of the cultivated or barren land, grasslands, shrubs, woodlands, and wetlands. The latitudinal and elevational zoning controls permafrost degradation, but local factors also have important influences, resulting in abrupt changes in permafrost conditions. In particular, anthropogenic activities have played, are playing, and will be playing very important roles in permafrost degradation and changes in cold regions eco-environments in the Hinggan Mountains, the northeastern China. Here human impacts on permafrost degradation might be the most prominent and could result in grave socio-economical and environmental impacts if they are not managed properly and timely.