Abstract
Mesa Verde consists of a series of mesas in a north to south trend. The mesa tops are narrow strips, cut by numerous canyons of varying depth. Mesa Verde sandstones, particularly the Cliff House Formation, form the canyon slopes. Long Mesa, an area of focus in this study, has an elevation 2180 m at the south to 2517 m at the north end. Long Canyon cuts down to an elevation of 2133 m. The vegetation on Long Mesa is a mosaic of mature pinon-juniper woodlands and mountain shrub associations. Shrub associations range from Gambels oak, (Quercus gambelii), and serviceberry, (Amelancheir utahensis), to Black Sagebrush, Artemesia nova), and Bitterbrush, (Purshia tridentata). Although there is a body of information concerned with the effect of fire on pinon-juniper woodlands, there are no adequate studies of the shrub-rich pinon-juniper ecosystem of Colorado. Succession following fire was documented by Erdman (1970) in Mesa Verde National Park. He reported that annuals dominate initially, then perennial grasses and forbs, followed by shrub invasion. The open shrub stage becomes a "thicket" approximately 100 years after the fire. The shrubs, he suggests, are outcompeted by pinon and juniper trees, which dominate by about 300 years. Fire and its relationship to resource management in Mesa Verde Park has been outlined by Omi and Emrick (1980). Focus was given to succession (cover and frequency of grass and shrub elements) following the 1873, 1934, and 1972 fires, and models predict the possibilities of control over moderate and severe fires in various vegetation classes within the Park. The study was concerned primarily with the nature of fire behavior and various fire-related management tools for use by Resource Management personnel.