Silviculture of Acadian Spruce-fir Forests: Soil-Site Relationships

This chapter first reviews landscape patterns as they relate to the many forest types in which red spruce and balsam fir occur, emphasizing the important concept of the soil catena - a variation in soils resulting from differing soil drainage over a common parent material. The distribution of area in Maine’s spruce-fir forest types by drainage classes and parent material is tabulated. All NRCS soil series in Maine are listed by parent material and drainage class so that the forester can use Soil Web or Web Soil Survey to assess productivity. The history of soil-site productivity research is reviewed, and the Influence of soil drainage class on site index is described. Site index curves and equations are provided for red spruce and balsam fir, including a procedure for determining a free-growth age for trees with histories of growth suppression.