Infiltration Rates of Various Vegetative Communities within the Blue Mountains of Oregon

Abstract

Mean infiltration rates differed among several natural vegetation communities with ponderosa pine (Pinus ponderosa) exhibiting the lowest mean infiltration rate of 6.0 cm/hr and larch (Larix occidentalis) demonstrating the highest at 8.8 cm/hr. A trend toward increasing infiltration rates corresponded to increasingly mesic sites. Alpine, Douglas fir (Psuedotsuga menziesii), mountain meadow, and larch types demonstrated the greatest vegetative cover, occupied the most mesic sites, and exhibited the highest infiltration rates. Infiltration differences within vegetative communities based upon changes in condition and productivity were also noted. The forested sites were more dependent upon condition class than productivity class, with higher infiltration rates being exhibited on pole sites than on timbered sites, apparently in response to higher plant densities associated with the pole thickets. Nonforested sites were responsive to both productivity and condition class with higher infiltration rates being exhibited on these sites with the more productive or better condition classifications.