Final Report, Forest Restoration of Sun Creek, Crater Lake National Park
In order to determine the spatial pattern of the major forest trees, a technique called “relative dispersion” was employed to see whether species were regularly, randomly, or contagiously dispersed relative to other species present. The effects of logging and presence or absence of fire were measured.
All species had contagious distributions in the nineteenth century. This means that pines were found in discrete groups and firs were also found in separate groups. This clumping of small groups of pure species was not affected by fire suppression, although the forest is now so thick with white fir reproduction that the clumps are not easily identified by sight. Logging removed the clumped pattern of ponderosa pine, but sugar pine, which was also logged, regenerated in a clumped fashion. Prescribed fire had variable effects on species pattern; it tended to restore clumped patterns for ponderosa but reduced clumping for sugar pine.