Soils and Topography
The soils where red spruce and its associates grow are mostly acid Spodosols, Inceptisols, and sometimes Histosols with a thick mor humus and a well-defined A2 horizon- characteristics commonly associated with abundant rainfall, cool climates, and softwood cover (11). Commonly, the pH of these soils ranges from 4.0 to 5.5. In northern New England, red spruce is found predominantly on shallow till soils that average about 46 cm (18 in) to a compact layer. It will grow on many sites unfavorable for other species, such as organic soils overlying rocks in mountainous locations, steep rocky slopes, thin soils, and wet bottomland (26). On poorly drained soils, lack of aeration limits growth (22).
In the northern part of its range, red spruce grows at elevations from near sea level to about 1370 m (4,500 ft) (22). In the southern Appalachian Mountains it comes in at elevations as low as 1370 m (4,500 ft) and from there to about 1520 m (5,000 ft) it is mixed with hardwoods and eastern hemlock (Tsuga canadensis). At 1520 m (5,000 ft) balsam fir (Abies balsamea) joins with red spruce to form the dominant spruce-fir climax type. In West Virginia, spruce-fir stands are found as low as 980 m (3,200 ft). Above 1890 m (6,200 ft) in the southern Appalachians, red spruce appears less frequently than Fraser fir (Abies fraseri) (47). In the White Mountains of New Hampshire, balsam fir is the predominant species above 1220 m (4,000 ft) but red spruce is well represented from about 790 to 1010 m (2,600 to 3,300 ft) (27).