Changes in forest soils as the result of exotic diseases, timber harvest, and fire exclusion and their implications on forest restoration

Abstract

In the western United States and throughout the world, three general classes of coniferous forests can be identified with each having similar vegetative complexes, native disturbances, and climate (Daubenmire and Daubenmire 1968, Hann et al. 1997). Dry forests, often dominated by pines (Pinus), cold forests often dominated by spruces (Picea), and moist forests dominated by hemlocks (Tsuga) represent the majority of the world's forests. The soils within each of these forest classifications are a product of their inherent climate and vegetation dynamics. Because soils are the foundation of the forest ecosystem, they are integral to all forest restoration efforts. However, because people value and cherish trees, they are often the focus of most restoration activities and the changes occurring in forests are most noticeable in the tree component. Presently in the western United States the most evident changes in many forests are the large number of trees occupying them compared to the amounts of trees that occurred in historical (pre- 1900) forests. In several forests not only has the number of trees increased but their composition is far different than what occurred historically. Normally, in the absence of disturbance, early-seral (shade intolerant) vegetation is succeeded by mid- and late-seral (shade tolerant) vegetation.

Citation

Graham, Russell T.; Jain, Theresa B. 2007. Changes in forest soils as the result of exotic diseases, timber harvest, and fire exclusion and their implications on forest restoration. In: Stanturf, J., ed. Proceedings of the IUFRO Conference on Forest Landscape Restoration; 2007 May 14-16; Seoul, Korea. Seoul, Korea: Korea Forest Research Institute. p. 126-131.