Keith B. Aubry
U.S. Forest Service
PNW Research Station

Twice each summer in all treatments, a foliated branch was clipped at 3 crown levels of 1 overstory
Douglas-fir, and near the ground on 3 understory vine maples. This was done for 1 year prior to treatment, and for 2 consecutive years after treatment.

„ Canopy arthropods showed little response to DEMO harvest treatments - changes in abundance in the harvest treatments were similar to those in the controls.
„ At the scale of this study, canopy arthropods responded more to regional variation in environmental conditions and changing weather patterns than to changes in canopy structure.

„ Litter arthropods more likely to respond to DEMO harvest treatments than canopy species.
„ Sensitivity to changes in moisture, temperature, and availability of resources.
„ Litter-dwelling spiders and carabid beetles
„ 5–7 years after harvest, used small pitfall traps with preservative during summer for 2 years in
5 of the 6 treatments in 4 of the 6 blocks.

„ Xeric- or open-habitat spiders increased after timber harvest.
„ Interior-forest spiders decreased.
„ Level of retention had little effect on the magnitude of decreases.
„ Pattern of retention had no effect on responses by any group of spiders.

„
Abundance and species richness of carabid beetles declined significantly in the harvest treatments.
„
Open-habitat species did not colonize harvested units as expected.
„
As with spiders, level and pattern of retention had little effect on the magnitude of treatment responses.

„ Interior-forest spiders and carabid beetles declined significantly in abundance with proximity to forest edge.
„ Aggregates provided better habitat than clearcut areas for interior-forest species in both groups, but provided poorer habitat conditions than undisturbed forest.

„ 5-7 years after harvest, none of the treatments provided suitable habitat for forest-dependent, litter-dwelling spiders or carabid beetles.
„ Strong edge-related declines in 1-ha aggregates suggest that smaller patches permitted under the NWFP (0.2-1.0 ha) are unlikely to support many old-forest taxa .

„ All wildlife sampling – 2 consecutive years both before and soon after harvests.
„ Amphibians & forest-floor small mammals
„ Pitfall trapping for 4 weeks after the onset of fall rains.
„ Breeding birds
„ Point-counts (all 6 blocks) and territory or spot-mapping (4 WA blocks only) during spring.

„ No evidence that salamanders responded to level or pattern of retention 2 years after harvest.
„ Due to their longevity and high sitetenacity, responses to harvest probably occur over longer time frames.
„ Captures after harvest were associated with ground cover (CWD or herbs).

„ Among interior-forest species, only the western red-backed vole responded negatively to harvest intensity.
„ Others – neutral or inconsistent reponses.
„ Open-habitat species (deer mouse, longtailed vole, and creeping vole) generally increased with harvest intensity.
„ No responses to pattern of retention.

„ Responses strongly influenced by regional variation in habitat conditions and species composition.
„ Western red-backed voles were significantly reduced or extirpated in all harvested areas – persisted only in undisturbed forest or in the aggregates.
„ Abundance lower in aggregates than controls
– lower habitat value than undisturbed forests.

2 years after harvest, canopy-nesting and bark-gleaning birds responded negatively to 15% retention, regardless of pattern.
Golden-crowned
Kinglet 7
6
5
4
9
8
0
9
8
7
3
2
1
6
5
4
3
0
9
2
1
8
7
6
5
4
3
2
1
0
100%
40% D
15% D
Pre
100%
40%D
15%D
Post 1 Post 2
Time
75%
Pre
75%A
40% A
40%A
15% A
15%A
Post 1 Post 2
7
6
5
4
9
8
0
9
8
7
3
2
1
6
5
4
3
2
1
0
9
8
7
6
5
4
3
2
1
0
Brown
Creeper
1
0
5
4
3
2
1
0
5
4
3
2
100%
40% D
100%
40%D
2
1
0
5
15% D
4
3
15%D
Pre Post 1 Post 2
75%
40% A
Time
75%A
40%A
15% A
15%A
Pre Post 1 Post 2
1
0
5
4
3
2
1
0
5
4
3
2
5
4
3
2
1
0

Negative responses to 15% retention also seen in reproductive indices.
Chestnut-backed
Chickadee

„ In the short term, intensity of post-harvest treatments may have a greater effect on responses of salamanders and small mammals than level or pattern of retention.
„ Providing CWD volume and herb cover in managed forests would improve habitat quality.
„ For many small mammals, regional differences in moisture regimes will influence the amount of retention needed to obtain comparable habitat benefits.

„ Except for western red-backed voles, which persisted only in aggregated retention, the pattern of retention had little effect on forest-floor arthropods, amphibians, small mammals, or birds at the treatment level.
„ Although aggregates are “lifeboats” for many forest attributes over the short term, for many interior-forest arthropods and mammals, aggregates >1 ha will be needed.

„ Retention levels at or below 15% appear to be inadequate to maintain populations of canopy-nesting or bark-gleaning birds over the short term.
„ For this and all other response variables, continued research is needed to determine how responses change as the
DEMO stands develop.

„ This past year, a team of 4 PNW scientists conducted a comprehensive re-assessment of the wildlife component of DEMO.
„ What worked? What didn’t? Why not?
„ Information obtained from that assessment, this workshop, and other sources will be used to improve the quality of future wildlife research in DEMO.
„ Similar process for other disciplines.