Plant Community Changes at Bryce Canyon National Park from 1957-1980, Part III, Forests of Bryce Canyon National Park: Consequences of Past Management Policies and Recommendations for the Future

Buchanan, Hayle; Harper, Kimball

Prior to the inclusion of Bryce Canyon National Park into the National Park System, the forest communities of the Paunsaugunt Plateau had been greatly modified by man's exploitative activities, especially logging and grazing by domestic livestock. Other prior disruptions of the biota included predator control, hunting, water diversions, and accidental as well as purposeful introductions of exotic plants and animals. Since 1928 the area has been partially protected from livestock grazing by fencing. Wildfires have been vigorously suppressed, and occasional epidemics of bark beetles and defoliating moths have been combatted with pesticides. Despite these unnatural interventions in the natural dynamics of the park's ecosystems, there appears to have been a tacit assumption that natural biological succession would result in pristine forests comparable to those that prevailed before the arrival of white settlers in the 1870's. The viewpoint that a disturbed and degraded forest would revert to a high quality pristine forest by simply being left alone while being protected from fires, insects, grazing and logging is unrealistic and ecologically unsound. Evidence is accumulating in the literature and through field observation of fire scarred older trees that light fires were part of nature and were a major factor in the development of the pristine forests. Many experts of forest sciences are of the opinion that some insect epidemics of the 20th century forests have been facilitated by fire and pest control programs. Prior to partial fencing to exclude domestic livestock from the park's meadows and forests, almost 60 years of uncontrolled grazing had undoubtedly resulted in a loss of ground cover and an acceleration of soil erosion. The light ground fires that frequently swept the understories of forests in early settlement times were probably fueled in large part by a blanket of perennial herb cover that has since been destroyed by persistent over-grazing. Soil erosion and increased cover of shrub and tree reproduction may make it difficult to reinstate an herbaceous cover comparable to that which fueled pre-settlement ground fires.