This study evaluated relationships between site or tree characteristics and below-ground materials in Douglas-fir forests of the Pacific Northwest. We core-sampled living roots, dead organic matter, and mineral fragments at three soil depths on a 300-sample grid at nine forested sites in western Washington and Oregon resulting in approximately 7200 samples. We explored relationships between materials across depths and at three scales—point, block and site—and examined the data to quantify the degree of spatial clustering. Mass of roots and organic matter declined with depth; there were no consistent patterns with depth for mineral fragments. Correlations between values at the same point but at different depths were low for roots and organic matter at all sites (mean r values < 0.3). Total soil carbon per site was negatively correlated (r = -0.85) with total root mass; correlations between other site or tree variables and below-ground materials were much lower (r = -0.21 to 0.34). There were no detectable spatial patterns in root mass. The number of samples needed to estimate mean root mass was calculated by site and for several desired precision levels; this power analysis will aid others working at similar sites in determining necessary sample sizes a priori, or conversely, in estimating level of precision given a particular sample size. Precision of ± 1.5 kg m^-3 could be achieved with less than 100 samples in the upper layer at most sites.

A paradox in managing threatened and endangered species is the increased need for documenting population status, which in many instances requires capturing and handling individuals. Electrofishing is a widely used method for sampling fish in small streams, but the potential for detrimental effects call for its careful use. Methods that reduce exposure for individual fish, yet still provide useful abundance estimates, are therefore desirable. Using data from a juvenile steelhead (Oncorhynchus mykiss) monitoring program in Idaho, we quantified variation and bias in capture probability from three-pass depletion electrofishing, and evaluated a method for indexing abundance based on single-pass electrofishing. Capture probability varied primarily at the level of sampling visits, with little spatial variation (i.e. at the level of the study sites). Water temperature, channel depth and, to a lesser degree, discharge best described the variation in capture probability between sampling events. We found no effect of previous capture and handling on individual capture probability, and the capture probability did not differ between subyearling and overyearling fish. Finally, a simple mixed-effects model with study site as a random effect, which related first-pass catch to the associated multiple-pass removal estimate, explained 91% of the variation in our data. The main limitation of the approach is that it does not provide error propagation and confidence intervals to the abundance estimates. However, the approach can be useful where multiple depletion electrofishing data exist, and when a single point estimate is sufficient to monitor major population trends in small streams.

The wrinkled dove snail (Amphissa columbiana) is a columbellid gastropod common in marine waters along the west coast of North America. This species has long been anecdotally described as an opportunistic scavenger, but little is known about its diet or scavenging behaviors. A. columbiana were observed at subtidal sites within the San Juan Islands, Washington to document associations with potential food items. Laboratory experiments were done to determine what this species eats and how it finds food. In the field, A. columbiana were often found on dead or damaged organisms, frequently in aggregations. In the laboratory, the snails consumed a broad range of dead or damaged invertebrate prey, showing little discrimination. They appear to locate food resources primarily through chemosensory cues, often following conspecific mucus trails and sometimes congregating around actively feeding sea stars. The chemical cues that draw A. columbiana to food act as feeding stimulants; the addition of scent from a damaged animal induced the snails to feed on healthy prey. The ability to sense chemical cues from damaged animals, including those being consumed by feeding sea stars, creates scavenging opportunities other gastropods may be unable to exploit.

Beargrass (Xerophyllum tenax [Pursh] Nutt.) is an herbaceous, evergreen perennial found in higher elevations of the northern Rocky, Sierra Nevada, Klamath, Siskiyou, Cascade and Olympic Mountains and in coastal areas from Washington to northern California. It is used by Native Americans for basketry and is an important floral green, but the conditions needed for reproduction and commercially valuable characteristics are not well known. We studied how the light environment affects size, morphology, color, and reproduction of a lowland, southeastern Olympic Peninsula beargrass population. We examined beargrass crown size distribution in relation to current and past overstory structure and found that beargrass plants had longer, greener leaves, lower crown density, smaller basal diameter, and fewer vegetative offshoots in shaded areas compared to more open areas. Flowering was less and there were fewer seedlings in shaded areas. Beargrass did not reproduce sexually in areas with < 0.3 of full photosynthetically active radiation (equivalent to at least 50% tree cover in our stand). Beargrass abundance matched the locations of anthropogenically maintained woodland openings that have since become forested preventing beargrass reproduction, suggesting that many plants have survived in the shade for more than 60 years. Overstory removal and prescribed burning in a portion of the stand stimulated sexual and asexual reproduction. We concluded that plants in shaded areas, although of somewhat higher commercial quality, are likely to recover more slowly from foliar harvest, and are less likely to be replaced after mortality. Population sustainability requires periodically or permanently open stand conditions.

We investigated the demography (emergence, dormancy and recruitment) of the pumice moonwort, (Botrychium pumicola) (Ophioglossaceae), a rare fern endemic to the Cascade Range from central Oregon to northern California. Populations of B. pumicola have been declining in low elevation basin sites likely due to climate change. Determining the demographics of subalpine populations is important for management of the species. At three subalpine sites at Crater Lake National Park, Oregon, individual B. pumicola plants were tagged, mapped and monitored for six consecutive years. In sample plots, the population of B. pumicola was stable over the six-year period with recruitment rates approximating dormancy and death rates. The annual dormancy rate was 6.4% and annual recruitment rate was 9%. Plants that went dormant and new recruits were smaller in stature than those of the original tagged plants suggesting that these plants were experiencing factors affecting fitness. Reduced pre-dormancy sporophore production and plant stature was a predictor of population decline. Variations in snow depth did not affect plant emergence, recruitment, or dormancy. Our results show that B. pumicola does not have a large below-ground reservoir of dormant rhizomes and the aboveground population most accurately represents the total population of adult individuals. Tracking B. pumicola individuals provides valuable information for management of this elusive species.

Understanding costs and effectiveness of mechanical fuels treatments is essential for efficiently influencing fire behavior at the landscape scale. While the capability of mastication to mitigate the potential of high severity wildfire in mature stands has been studied, the variables that determine its efficiency across age classes have received far less attention. The objective of this study was to examine how stand age influenced the efficiency and effectiveness of mastication. Mastication was performed on stand ages and structures representative of those commonly observed in the mixed conifer forest of the Sierra Nevada. Machine data from spatial and motion sensors were used to assess machine efficiency, and fire modeling was used to evaluate treatment effectiveness. The stands masticated were 10, 33, and 100 years old. Machine operation time per hectare was shown to vary with stand age, with the 10 and 100-year-old stands less costly to treat than the 33-year-old stand. However, potential for high severity wildfire immediately following treatments was reduced to a much greater degree in the 33-year-old stand, whereas it increased for the 10-year-old stand and was unaffected in the 100-year-old stand. This study's findings suggest that masticating developing stands (i.e. those entering the stem exclusion phase), while relatively costly, may also provide managers with a big “bang for their buck” in reducing fire severity across the landscape. To assess longer-term effectiveness, it will be important to track predicted fire severity as masticated fuels decompose and as tree growth responds to the reduction in density following the treatments in stands of various ages.

Wolverines (Gulo gulo) within the conterminous U.S. exist as a metapopulation dependent upon individuals dispersing between patches of habitat to persist. Dispersal events can be difficult to document for long-ranging carnivores, but have implications for understanding gene flow and connectivity between both currently occupied and historically occupied habitat. Here, we describe the long-distance dispersal of a subadult, male wolverine (M56) from a reproductive population in northwest Wyoming to northern Colorado where wolverines had been absent for 90 years. M56 was ultimately killed in North Dakota in 2016, the first verified wolverine in that state in over 200 years. Following capture and collaring, we collected aerial VHF telemetry locations as M56 navigated potential barriers, including interstate highways and subdivisions, and travelled extensively outside of primary wolverine habitat through the arid grasslands and shrublands of the Wyoming Basin Ecoregion. Straight-line distances for dispersals from Wyoming to Colorado (516 km) and from Colorado to North Dakota (826 km) are the longest straight-line dispersal distances reported for the species at this time. The Wyoming Basin Ecoregion M56 traversed is dominated by sagebrush and topography less rugged than that typical of the high elevation, mountainous habitat wolverines use in the conterminous U.S. This dispersal event offers evidence of connectivity between occupied habitat in Wyoming and unoccupied habitat within the species' historic range in Colorado and provides a detailed account of the path M56 took through atypical habitat.