一、自然条件 大兴安岭寒温带林区,处在黑龙江省的北部,约50°00′—53°31′N的地区。区内地形属丘陵和低山,海拔300—600米。山间河谷平原和河漫滩上因水淤积,地下水位过高而发育有沼泽;宽谷内发育有阶地。一年中,有半年时间地表冻结,以至在夏季,地表一米以下还有厚约3米的永冻层。中部的伊勒呼里山(最高山峰海拔1530米)把全区分为南北两部分,北部属黑龙江水系,南部属松花江流域。黑龙江畔海拔170—300米,松花江 First, the natural conditions Daxinganling cold temperate forest, in the northern Heilongjiang Province, about 50 ° 00’-53 ° 31’N area. The terrain is hilly and low mountains, elevation 300-600 meters. Mountain valley plains and river floodplain due to water siltation, groundwater level is too high and the development of a swamp; wide valley within the development of terrace. During the year, there is a freeze on the surface for six months, so that in summer, there is a permafrost about 3 meters below the ground one meter below. The middle of the Lelehuli Mountain (the highest mountain elevation of 1530 meters) the whole area is divided into two parts north and south, north of Heilongjiang River, the south belongs to the Songhua River. Heilongjiang River elevation 170-300 meters, the Songhua River