Karl J. Martin

Movements of northern flying squirrels in different-aged forest stands of western Oregon

In western Oregon, northern flying squirrels (Glaucomys sabrinus) are the primary prey species for northern spotted owls (Strix occidentalis caurina), a old-growth associated species. To assess differences between old-growth and second-growth habitat, we livetrapped and radiotagged 39 northern flying squirrels to estimate their home range sizes and describe movements in 2 old-growth and 2 second-growth conifer forest stands in the Cascade Mountains of central Oregon. Sampling periods were summer and fall of 1991-92. Home range sizes averaged 4.9 ha and did not differ (P > 0.30) between the 2 stand types. Male northern flying squirrels had larger (P ≤ 0.03) mean home ranges (5.9 + 0.8 ha: x + SE; n = 20) than females (3.9 ± 0.4 ha: n = 19). Northern flying squirrel movement distances between successive, noncorrelated telemetry locations averaged 71 m (n = 1,090). No correlation was found between distances moved and stand type or sex Northern flying squirrels home range sizes, movements, and densities were similar between the 2 stand types We suggest abundance and movements of northern flying squirrels are not influencing the preferential selection of old-growth forests by northern spotted owls.

Amphibian habitat associations at patch and landscape scales in the central oregon coast range

We examined capture rates of amphibians in 30 250-300-ha landscapes in the central Oregon Coast Range, Oregon, USA, to better understand multiscale habitat associations. We compared capture rates of 5 species that had 26-79 captures to expected capture rates based on sampling effort in 7 vegetation patch types and 4 species with 208-482 captures in 11 patch types. Capture rates of 8 amphibian species were higher (P< 0.05) in conifer and/or mixed large sawtimber patch types than in other patch types. We also examined associations between landscape-level capture rates and both percent area of patch-type and 8 pattern indices. The percent area of conifer and/or mixed large sawtimber patch types was associated with capture rates of 5 amphibian species, and various pattern metrics were associated with the capture rates of 4 amphibian species. We found that most amphibian species were associated with unique habitat conditions, making managing across amphibian species difficult. Applying the intermediate disturbance hypothesis at the landscape scale may provide a useful management concept for maintaining suitable habitat conditions for a wide diversity of amphibian species. Mature forest area, patch richness, pattern, and composition seemed to be key features associated with amphibian abundance and distribution that should be considered in management plans when biodiversity of amphibians is a management objective.

GOLDEN-WINGED WARBLER HABITAT USE AND ABUNDANCE IN NORTHERN WISCONSIN

Abstract Golden-winged Warblers (Vermivora chrysoptera) are declining in the eastern portion of their range partially due to a loss of shrub-scrub and early successional habitat. We surveyed Golden-winged Warbler abundance in shrub swamp, young aspen (Populus spp.), heavily thinned hardwood, jack pine (Pinus banksiana), and two edge cover types (i.e., swamp/aspen and swamp/mature) in 2002–2004 in northern Wisconsin. Golden-winged Warbler abundance was greatest in young aspen stands (1–10 years of age) and least in the swamp/ mature edge cover type. Abundance did not differ among years in any of the cover types. Aspen stem density was positively related to Golden-winged Warbler abundance among stands. The presence of Golden-winged Warblers within stands, at the sampling station scale, was positively correlated with aspen stem density, the amount of low woody cover, and ground vegetation. The most effective way to manage for this species in the north central portion of its range may be through the creation of young aspen forests and by maintaining shrub-scrub habitat.

Nesting patterns of southern flying squirrels in managed northern hardwoods

Abstract Southern flying squirrels (Glaucomys volans) use multiple nest trees for foraging and protection, but nest trees can become scarce following harvests of hardwood forests. In northern Wisconsin, the Managed Old-growth Silvicultural Study tested techniques to remediate logging impacts on forest-dependent wildlife. Three types of canopy treatments were applied (multicohort harvest [0.4-ha and 1.2-ha irregular group shelterwoods], medium gaps [18-m- and 24-m-diameter gaps], and small gaps [11-m-diameter gaps]). To evaluate the effects of treatment on nest tree selection by southern flying squirrels, we tracked 33 radiocollared southern flying squirrels once a week for 5 weeks in late summer, locating 82 nest trees (X¯ =  2.73 nest trees per southern flying squirrel [95% confidence interval: 2.28–3.18 nest trees]). Canopy treatments were important predictors of nest tree switching. Probability of switching differed by canopy treatment (listed from lowest to highest probability): multicohort harvest: 0.29 (0.17–0.42), medium gaps: 0.44 (0.32–0.56), control: 0.57 (0.41–0.73), and small gaps: 0.73 (0.61–0.85). Lower nest tree switching in the multicohort harvest compared to the small gaps likely reflected availability of habitat resources. Spatial arrangement of canopy gaps and associated effects on southern flying squirrels should be considered when planning timber harvests in northern hardwoods.

NEST-SITE SELECTION, NEST SURVIVAL, PRODUCTIVITY, AND SURVIVAL OF SPRUCE GROUSE IN WISCONSIN

Abstract Spruce Grouse (Falcipennis canadensis) are listed as threatened in Wisconsin, and the boreal habitats in which they occur are likely to be threatened by changing climatic conditions. However, the limited information available on Spruce Grouse in the Upper Great Lakes region makes it unclear which habitat features are important for Spruce Grouse nesting in Wisconsin. We radiotracked 30 female Spruce Grouse in northern Wisconsin from 2007–2012 and located 25 nests. Eighteen of 25 nests were beneath black spruce (Picea mariana) trees. Only three nests were in upland, and only one in a stand of jack pines (Pinus banksiana), in contrast to studies from Michigan and Ontario. Overall concealment was a good predictor of nest sites for Spruce Grouse, but not a good predictor of nest survival. Nest survival was associated with moderately dense and uniform 0–0.5 m lateral vegetation cover. Seventeen of 25 nests were successful, with a daily survival rate of 0.985, overall productivity of 1.0 young/female, and 1.9 young/successful nest. Annual survival of adult males was estimated at 54%, adult females at 40%, and juvenile survival at 14% and 24% by two different methods. Estimates of &lgr; of 0.65 and 0.67 suggest a declining population, but the upper confidence limit exceeds 1, not ruling out a stable or slightly increasing population. Protecting black spruce swamps will protect important nesting habitat for Spruce Grouse in Wisconsin.

Accelerating the development of old-growth characteristics in second-growth northern hardwoods

Active management techniques that emulate natural forest disturbance and stand development processes have the potential to enhance species diversity, structural complexity, and spatial heterogeneity in managed forests, helping to meet goals related to biodiversity, ecosystem health, and forest resilience in the face of uncertain future conditions. There are a number of steps to complete before, during, and after deciding to use active management for this purpose. These steps include specifying objectives and identifying initial targets, recognizing and addressing contemporary stressors that may hinder the ability to meet those objectives and targets, conducting a pretreatment evaluation, developing and implementing treatments, and evaluating treatments for success of implementation and for effectiveness after application. In this report we discuss these steps as they may be applied to second-growth northern hardwood forests in the northern Lake States region, using our experience with the ongoing managed old-growth silvicultural study (MOSS) as an example. We provide additional examples from other applicable studies across the region.

Understanding Climate Adaptation on Public Lands in the Upper Midwest: Implications for Monitoring and Tracking Progress.

There are limited examples of efforts to systematically monitor and track climate change adaptation progress in the context of natural resource management, despite substantial investments in adaptation initiatives. To better understand the status of adaptation within state natural resource agencies, we utilized and problematized a rational decision-making framework to characterize adaptation at the level of public land managers in the Upper Midwest. We conducted in-depth interviews with 29 biologists and foresters to provide an understanding of managers’ experiences with, and perceptions of, climate change impacts, efforts towards planning for climate change, and a full range of actions implemented to address climate change. While the majority of managers identified climate change impacts affecting their region, they expressed significant uncertainty in interpreting those signals. Just under half of managers indicated planning efforts are underway, although most planning is remote from local management. Actions already implemented include both forward-looking measures and those aimed at coping with current impacts. In addition, cross-scale dynamics emerged as an important theme related to the overall adaptation process. The results hold implications for tracking future progress on climate change adaptation. Common definitions or measures of adaptation (e.g., presence of planning documents) may need to be reassessed for applicability at the level of public land managers.

Correction to: Climate change surpasses land-use change in the contracting range boundary of a winter-adapted mammal

[ Proc. R. Soc. B 283 , 20153104. (Published 30 March 2016) ([doi:10.1098/rspb.2015.3104][2])][2] The original article incorrectly cites Hammer et al. 2004 in subsection ‘Land cover analysis’ of ‘Material and methods’. Where the text states ‘To account for the influence of forest