Final Report, Forest Restoration of Sun Creek, Crater Lake National Park
The Sun Creek area of Crater Lake National Park began to be protected from naturally-occurring, frequent, low intensity surface fires at the beginning of the twentieth century. During the 1930’s, the area, which was then a private inholding within the park, was logged: ponderosa and sugar pines were selectively removed. Due to this incompatible use, the area was added to Crater Lake National Park in 1941. It has been protected from disturbances since then.
The park staff requested an assessment of the degree of disturbance caused by logging and fire suppression, and techniques available to restore the area to “natural” conditions. We identified two forest types, and established permanent 0.25 ha plots in both logged and unlogged areas of each type. The objective of detailed plot work was to determine historic and current forest structure, and the immediate effects of -e prescribed fire across each plot. Reconnaissance level surveys were done to assess spatial pattern of trees, and the present tree stocking in logged areas.
The results indicated that the forests in the 1800’s were predominantly pine forests, and that sugar and ponderosa pine, as well as white fir, tended to grow in clumps. Logging had obvious effects on species composition by removing the overstory pines. Pine regeneration occurred in some areas but not others after logging.
Introduction of prescribed fire as a restorative treatment caused 75-85 percent mortality of trees below 5.5 cm dbh; much less mortality occurred in larger diameter classes. White fir was more sensitive to fire than sugar pine; ponderosa pine appeared to be most resistant. Three management areas were delineated across the Sun Creek area: (1) Understocked Ponderosa Pine Area (355 ha, 875 ac); (2) Stocked Ponderosa Pine Area (190 ha, 465 ac); and (3) Stocked Sugar Pine Area (120 ha, 300 ac). In the first area, the lack of pine regeneration and seed source for pines will require planting of pines as well as reintroduction of fire. For the other two areas, careful reintroduction of fire alone should be sufficient, as pole-size pine are present in the stocked areas and only need selective favoring over white fir. Fire prescriptions and planting recommendations are made for each area.
The restoration will require patience and substantial commitments of time and money. Planting trees in national parks is an unusual treatment but certainly justified to counterbalance past effects of logging. In another century, the Sun Creek landscape can be largely restored to a mimic of wilderness character.
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