Lodgepole Pine at Crater Lake: History and Management of the Forest Structure
VIII. Suggestions for Management
The forests of lodgepole pine in Crater Lake National Park vary in their characteristics, their environment, their potential for supporting fir-hemlock forest, and their apparent history. This variability existed previous to white man’s influence and must be reflected in the specific management plans prepared for each area.
We feel that the only management tool reasonably available to the park is the control or use of fire. Direct control of bark beetles and dwarf mistletoe is neither desirable nor feasible for the large areas involved; following a return to a natural fire regime, any deviations from primeval levels in these biological factors should again eventually decrease.
We have divided the lodgepole pine communities discussed above into five management units, each of which requires separate attention. Almost throughout, the differences from the ponderosa pine system are extreme. The species differ (long-lived and fire proof vs. short-lived and fire susceptible) and their fire histories are usually different (frequent ground fire vs. the five types, only one of which is like ponderosa). Thus management policy cannot be transferred from ponderosa to lodgepole forests. Specifically, controlled ground fire designed to release larger trees seems appropriate for only one type of lodgepole forest, and even there only in patches. There are several reasons for this. Such fires would be very difficult to produce with all but the lightest fuel loads; most surviving lodgepole pines will be killed by bark beetles or eventually succumb to heart rot. If it did prove possible, a series of this type of fire would allow large mistletoe-infected trees to remain, insuring heavy infection of most fire-stimulated reproduction and its subsequent deformity. Indeed, in the one community where repeated light fires apparently did occur the forest is in precisely this condition, and probably was so in the primeval state. In other types, when fire occurred it killed the overstory, removing the dwarf mistletoe from the site.
Fire seems also to be inappropriate to simulate or anticipate beetle- caused mortality. Beetle kill and fire will produce very different effects on the forest. Beetles “thin from above,” killing the largest trees and opening the canopy, accelerating growth of smaller trees, but not removing the litter. A light controlled fire “thins from below” (any trees which survive are likely to be the largest), killing reproduction of all species and removing the litter, encouraging lodgepole reproduction.
The adoption of the “natural fire policy” by the park will greatly reduce the need for man-initiated fire in the management of lodgepole pine forest, since lightning was the predominant ignition source in most primeval lodgepole in the Park.
The most obvious deviations from primeval structure were caused by white man’s promiscuous use of fire, so the suppression of man-caused fires has already served as one very large step toward returning the primeval processes. We suggest that fires obviously of man-caused origin continue to be suppressed in all areas of the Park. They have been in areas and forest types in a pattern which shows little correlation with natural ignition (see Fig. 1 in the Park Fire Management Plan). Another large step has now been taken in the decision to let some natural fires burn. In only a few types has the suppression of all fires resulted in large enough deviations from the primeval conditions to justify prescribed fire. In some other spots outside the natural fire area, it may be necessary to prescribe fire to substitute for the absence of natural fire, but these should be relatively few.