Record Details

Effects of clearcutting a Douglas-fir stand upon small animal populations in western Oregon

ScholarsArchive at Oregon State University

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Title Effects of clearcutting a Douglas-fir stand upon small animal populations in western Oregon
Names Hooven, Edward F. (Edward Frank) (creator)
Wheeler, William P. (advisor)
Date Issued 1971-05-10 (iso8601)
Note Graduation date: 1971
Abstract An ecological study of small forest mammals was conducted
from 1964 to 1970. The objectives were to obtain chronological information
relative to the effects of current logging practices on vegetational
succession and small mammal populations.
The locale of the study was in the west-central Cascade Mountains
of Oregon. The principal timber species was Douglas-fir,
Pseudotsuga menziesii. The climate was characterized by heavy precipitation
in the winter and dry summers. Snowfall varied from slight to
heavy. Elevation was 3000 feet.
The study areas were composed of a 125-year-old timbered control
unit, a clearcut non-burned unit, and a clearcut slash-burned unit.
Density and distribution of the small mammals were determined
by live-trapping and release of marked animals. Reproductive information
of some species was noted. Home range areas was computed for the more numerous species of rodents.
More than 4530 individual small mammals of 23 mammalian
species were marked on the three areas during the six years of the
study. Over 90 percent of the total animals caught consisted of five
species: Sorex spp, Eutamias townsendii, Peromyscus maniculatus,
and Microtus oregoni.
The small mammal densities varied from year to year. They
were comparable between units on a monthly basis except for the
unburned clearcut unit which differed for a year following logging.
Shrew numbers, abundant in the forest, were less on the unburned
and sharply reduced on the slash-burned unit. Deermice,
scarce in the closed forest, increased greatly in numbers on the clearcuts.
Chipmunks were abundant in the forest, less on the slash- burned
clearcut unit, and sharply reduced in numbers on the unburned unit.
Creeping mice were scarce in the forest but their numbers erupted on
the clearcuts. Snowshoe hares were, caught periodically in the timber
but not on the clearcuts.
Some species, caught infrequently or known only by sign, are
expected to increase and become more numerous as the vegetation
becomes brushier. These include the snowshoe hare, mountain beaver,
porcupine, and the pocket gopher.
The results of this study suggest that more information is
required relative to the diet of the small mammals. Effects of vegetational manipulation, by selective cutting practices or by the use
of herbicides on small mammals should be examined.
Genre Thesis/Dissertation
Topic Animal ecology
Identifier http://hdl.handle.net/1957/12964

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