As a result of fire supression, smaller forest openings allow for less understory growth (grasses and shrubs) and wildlife habitat. Small trees have been encroaching on meadows that once would have been maintained by frequent fires. There are now larger accummulations of built-up woody debris in the forest and more smaller trees, creating the potential for a catastrophic crown fire. All of these conditions combined have increased the potential for larger, more dangerous fires. For the past two decades, the National Park Service has restored fire to much of Yosemite, though the present program has not been able to meet the needs of the whole park. Prior to fire suppression, it is estimated that an average of 16,000 of Yosemite’s 747,000 acres may have burned under natural conditions in the park each year.
In Yosemite, fire records date back to 1930 and information is also available for about another decade of documented fire history. Therefore, fire managers at Yosemite have 80 years of records on fire and fire suppression activities on which to rely. In addition, tree ring studies provide a history of fire frequency dating back hundreds and thousands of years. This historical information has been of great importance in creating the goals and objectives for Yosemite's Fire Management Program and current Fire Management Plan.
