Geology topics

W.C. McComb

Publications and source records attributed to W.C. McComb.

3 recordsLinked to original sources

USGS1999

CFIRP: What we learned in the first ten years

In response to public dissatisfaction with forest management methods, we initiated the College of Forestry Integrated Research Project (CFIRP) to test alternative silvicultural systems in Douglas-fir (Pseudotsuga menziesii stands in western Oregon. We compared costs and biological and human responses among a control and three replicated silvicultural alternatives to clearcutting that retained structural features found in old Douglas-fir forests. Treatments were applied within 8- to 15-ha stands and attempted to mimic crown fires (modified clearcut), windthrow (green tree retention), and small-scale impacts such as root rot diseases (small patch group selection). We also compared costs in three unreplicated treatments (large patch group selection, wedge cut, and strip cut). Each treatment included differences in the pattern of retained dead trees (snags), as either scattered individuals or as clumps. Good communication among researchers and managers, a long-term commitment to the project, and careful documentation of research sites and data are important to the success of long-term silvicultural research projects. To date, over 30 publications have resulted from the project.

Conference Paper↗

USGS1997

Use of artificially created Douglas-fir snags by cavity-nesting birds

In western Oregon, we created snags by sawing tops off live Douglas-fir ( Pseudotsuga menziesii ) (n = 821) trees and monitored their condition and use by cavity-nesting birds. We created snags in three silvicultural treatments: modified clearcut stands, two-story stands, and small-patch group-selection stands. We used two snag patterns: clumped and scattered. Created snags averaged 3.8/ha in density, 17 m in height, and 75 cm in diameter. Chainsaw-topped snags were used by cavity nesters within 5 yr of creation. Abundance of excavated cavities increased in all silvicultural treatments (P = 0.0001) and was higher in two-story and clearcut stands than in small-patch stands (P ≤ 0.0004). We did not, however, find that snag pattern (clumped v. scattered) affected use by cavity-nesting birds based on abundance of excavated cavities (P > 0.6). We observed excavated cavities in five hardwood species indicating that hardwoods represented an important resource for cavity-nesting birds. Creating conifer snags by topping and retaining hardwoods may retain or increase populations of cavity nesters in areas with low natural snag density.

Oregon↗

USGS1996

Effects of silvicultultural modifications of temperate rainforest on breeding and wintering bird communities, Prince of Wales Island, southeast Alaska

We inventoried breeding and wintering bird communities in four treatments of temperate rainforest on Prince of Wales Island, southeast Alaska during 1991-1992 and 1992-1993. The four forest treatments sampled included: (1) young growth (20 years) originating from clearcut logging with no silvicultural modification (non-modified), (2) young growth (20 years) precommercially thinned along uniformly-spaced thinning grids (thinned), (3) young growth (20 years) with gaps in the overstory canopy created by felling trees in 0.05-ha openings (gapped), and (4) virgin old growth (2 150 years). Of 16 common breeding bird species observed, six showed significant responses to young-growth modifications. One species was more abundant and two species were less abundant in thinned sites, while one species was more abundant and two species were less abundant in gapped sites than at least one of the other treatments. None of the three common wintering species of birds observed was influenced by young-growth modification. Breeding bird communities, in general, were less similar between young- and old-growth treatments than among young-growth treatments. Three of the 16 common breeding bird species were more abundant in old growth than each of the young-growth treatments and one uncommon species was detected almost exclusivelyi n old growth duringb oth the breedinga nd wintering seasonsF. our other breeding bird species were more abundant in young-growth treatments than in old growth. Higher use of old growth by wintering birds was related to winter severity. To enhance habitat for wintering and breeding birds we recommend: (1) thinning young growth along variablespaced grids to create additional canopy layers and improve snow-intercept properties of young growth for canopy-foraging birds, (2) retention of old-growth clumps in clearcuts for bird species associated with old-growth structure, and (3) long-term conservation of oldgrowth temperate rainforest for breeding and wintering birds positively associated with old growth.

The Condor↗