Plant and Mannal Changes on a Clearcut In West‐Central Oregon

Abstract

Plant composition and coverage and small mammal populations were compared in virgin forest (control) and clearcut (experimental) areas from April 1954 to October 1965. Changes in ground cover vegetation were modest on the control area but marked on the experimental area. A late fall burn on the experimental area may have retarded herbaceous plant establishment. Nearly half of the herbaceous species were invaders not found in the virgin Douglas—fir (Pseudotsuga menziesii) forest. Ground plant coverage was less than 23% in the virgin forest; 1 year after the clearcut area was burned, the cover was 2%; and by 10 years it was above 53%. Woody plant coverage (mostly sprouts) was slightly more abundant the first 2 years after burning. Herbaceous species then became dominant for a 3—year period, after which woody plants gradually gained dominance. Deer mice (Peromyscus maniculatus) increased on the experimental area soon after the burn. The populations varied from an estimated 0.9 to 12.8 animals per acre and fluctuated widely and irregularly. Townsend's chipmunk (Eutamias townsendii), Oregon vole (Microtus oregoni), and snowshoe hare (Lepus americanus) populations also increased on the area at different periods after the burn. Trownbridge's shrews (Sorex trowbridgii), vagrant shrews (Sorex vagrans), and ermine (Mustela erminea) were present on both areas in relatively low numbers. Redback voles (Clethrionomys occidentalis), Douglas' squirrels (Tamiasciurus douglasii), and northern flying squirrels (Glaucomys sabrinus) were not found on the clearcut. California ground squirrels (Spermophilus beecheyi) migrated to the clearcut and established a modest population. Richardson's voles (Microtus richardsoni), jumping mice (Zapus trinotatus), bushy—tailed woodrats (Neotoma cinerea), and a pika (Ochotona princeps) were visitors.