The use of prescribed fire was accepted as a means of achieving resource and fuel reduction objectives on national park units in the late 1960s. Prescribed fire reintroduces the natural process of fire into the ecosystem. It is a tool for improving habitat, maintaining historic landscapes, protecting resources, and reducing exotic species. By reducing fuel loads, prescribed fire can lower the probability of a catastrophic fire occurring; catastrophic fires can lead to erosion, loss of seed sources and wildlife habitat loss, and increased insect and disease epidemics.