A large (> 200-cm diameter) coast redwood (Sequoia sempervirens) stump occurring upright on an Oregon beach, 257 km from the northern limit of its native distribution, may be a remnant of an extinct disjunct population or it may be the result of vertical emplacement of a drift log. Holocene tree stumps in situ in paleosols commonly emerge on the shore platform as a result of a complex history of dune activity, subsidence, and erosion. An historical account reported organic soils associated with the stump during the late 1800s; such soils are normally removed quickly by wave action after exposure. We used several methods to corroborate this account. The stump's in situ origin is supported by 1) a radiocarbon age indicating a death date between 1820 and 1720 years ago, coeval with other paleosols and in situ stumps; 2) its height and upright position, which are only matched by other in situ stumps; and 3) a photograph from 1912 showing uneroded wood inconsistent with a sea-drift history. Other evidence failed to support the in situ origin: 1) ground-penetrating radar did not reveal an associated paleosol, 2) the age of a nearby paleosols and stumps within 3 km were younger than the stump, and 3) three paleosols did not yield redwood pollen or wood. The only support for a sea-drift origin is that its age slightly predates a known tsunami that may have emplaced the stump. The balance of evidence suggests that the redwood stump is a remnant of an extinct late-Holocene disjunct population.

Lamprey populations are in decline worldwide and the status of Pacific lamprey (Entosphenus tridentatus) is a topic of current interest. They and other lamprey species cycle nutrients and serve as prey in riverine ecosystems. To determine the current distribution of Pacific lamprey in major watersheds flowing into Puget Sound, Washington, we sampled lamprey captured during salmonid smolt monitoring that occurred from late winter to mid-summer. We found Pacific lamprey in 12 of 18 watersheds and they were most common in southern Puget Sound watersheds and in watersheds draining western Puget Sound (Hood Canal). Two additional species, western brook lamprey (Lampetra richardsoni) and river lamprey (L. ayresii) were more common in eastern Puget Sound watersheds. Few Pacific lamprey macrophthalmia were found, suggesting that the majority of juveniles migrated seaward during other time periods. In addition, “dwarf” adult Pacific lamprey (< 300 mm) were observed in several watersheds and may represent an alternate life history for some Puget Sound populations. Based on genetic data, the use of visual techniques to identify lamprey ammocoetes as Entosphenus or Lampetra was successful for 97% (34 of 35) of the samples we evaluated.

Ciona savignyi is a solitary tunicate (Phylum Chordata, Class Ascidiacea) native to Japan that has invaded coastal habitats in the north-east Pacific and New Zealand. In the Puget Sound of Washington, USA, we examined the ability of C. savignyi to survive in artificially created hypoxic environments to determine if reduced dissolved oxygen (DO) treatments could be a viable control method. In laboratory bioassays, treatment groups that were immersed in DO concentrations ranging from completely hypoxic (1 mg/L) to low DO (5 mg/L) had zero survivorship of individually isolated tunicates after 14 to 22 days of exposure, respectively. Additionally, hypoxic conditions (approximately 1.5 mg/L) were created in the field using polyethylene tarp wraps applied around dock surfaces fouled with C. savignyi in a Puget Sound marina. To estimate mortality rates underneath the tarp wraps, dock units with clusters of C. savignyi remained wrapped for 10, 14 and 18 days and displayed decreasing survivorship with increased wrap time (76%, 51% and 33%, respectively). Our laboratory and field experiments indicate that wrapping docks fouled by C. savignyi with polyethylene tarps may be an effective management option to locally-control and reduce the spread of this tunicate species from marina habitats, which serve as hubs for non-native species transport via hull fouling. These results inform the development of a rapid response plan for C. savignyi in the state of Washington and may be a viable control method for other high priority non-native tunicates pending further work on species-specific tolerances to low DO.

We examined the patterns of space use and spatial organization of radio-tagged fishers (Pekania pennanti) in boreal mixed-wood forests in northeastern British Columbia, Canada between 2005 and 2009 to gain a better understanding of broad-scale population processes. We collected point locations from 17 radio-tagged fishers and estimated home ranges using the 95% isopleth of the utilisation distribution generated from the fixed kernel method. Aggregate home ranges averaged 30.6 km² for females (SD = 14.5, n = 13) and 210.3 km² for males (SD = 45.2, n = 4). Overlap of home ranges was common among individuals: 8 of 13 females had home ranges that overlapped portions of up to 3 other female home ranges, whereas home ranges of males overlapped 1 to 3 other males' home ranges, and male home ranges overlapped home ranges of 1 to 6 radio-tagged females. None of the observed instances of overlap were of parents and offspring. Given that the adult fishers that we radio-tagged had substantial omental and mesenteric fat deposits, we hypothesize that the patterns of space use that we observed were influenced by the distribution and abundance of resources needed for successful reproduction, rather than food.

The Point Arena mountain beaver (Aplodontia rufa nigra) is federally listed as an endangered subspecies that is restricted to a small geographic range in coastal Mendocino County, California. Management of this imperiled taxon requires accurate information on its demography and vital rates. We developed noninvasive survey methods, using hair snares to sample DNA and to estimate abundance and survival at two sites, Kinney Beach and Alder Creek, within Manchester State Park. We extracted DNA and genotyped 371 hair samples resulting in the identification of a total of 54 individuals during annual sampling from 2006–2009. Estimated population numbers were small, ranging from 9–18 individuals at Kinney Beach and 14–18 individuals at Alder Creek. Neither location demonstrated a trend in abundance over the 4-year sample period. There was weak support (evidence ratio 2.15) for higher apparent survival probabilities at Alder Creek (0.75) than Kinney Beach (0.59) and no support for time or site effects on recruitment. Recruitment ranged from 0.25 to 0.46 and was highest during the same interval (2007–2008) at both locations. The time series of estimates from 2006–2009 does not suggest that abundance at either study site is declining; while reassuring, concern still remains due to low total numbers at this, one of the few protected sites for this endangered subspecies.

The importance of climate warming on forests is recognized worldwide and has increased attention on the significance of both timberline advance and alpine meadow invasion by forests. Successful seedling regeneration in alpine meadows depends on availability of suitable substrates, or microsites, for seedling establishment. We sought to determine whether wood microsites (i.e., nurse logs), which are regeneration sites in Pacific Northwest subalpine forests, promoted regeneration at timberline-alpine meadow borders. To determine the ecological role of wood microsites, we examined mechanisms forming wood microsites; compared density, survival, and percent nitrogen content of seedlings growing on wood microsites to adjacent soil substrates; and compared substrate moisture, temperature, and percent nitrogen content. Wood microsites, at 13 of 14 randomly selected sites, were characterized by highly decayed downed wood (> 75% decay class five) originating from tree fall (66%), snow avalanches (17%), forest fires (15%), and by human cutting (2%). Although no differences in percent nitrogen content were detected, greater seedling densities, greater seedling survival, higher temperatures, and higher moisture contents were found on wood microsites compared to adjacent soil. We suggest that greater seedling density and seedling survival on wood microsites was associated with factors including heightened moisture and increased temperature. Assuming sustained downed wood input from timberline trees and continued viable seed input, we expect wood microsites will facilitate accelerated alpine meadow conifer invasion via wood microsites associated with climate warming.

Changing seasonal soil moisture regimes caused by global warming may alter plant community composition in sensitive or endangered habitats such as wetlands and oak savannas. To evaluate such changes, an understanding of typical seasonal soil moisture regimes is necessary. The primary objective of this study was to document seasonal soil moisture patterns in herbaceous plant communities across a range of soils typical of Willamette Valley wet prairie, floodplain, and oak savanna habitats. Volumetric soil moisture data were collected periodically from January 2010 through December 2011 at study sites using time domain reflectometry and converted to plant-available soil moisture using moisture release data for each of the soils. In addition, plant communities, soil texture, and soil chemical attributes were evaluated at all sites. Both 2010 and 2011 experienced unusually high spring rainfall, and soils did not begin dry down until about the third week in June. The length of the dry period was similar in both years, but in 2011 it was shifted from mid-July through early September to early August through early October. Well-drained floodplain soils consistently had the lowest soil moisture contents in both years. Wet prairie sites began to dry down shortly after oak savanna sites, and their rates and severity of dry down were similar. These results suggest that the composition of herbaceous plant communities in wet prairie habitats may be influenced more by winter and spring inundation than by summer drought and that the timing of rainfall events during the dry period could influence plant community composition.

To assess potential impacts of native and invasive terrestrial mammals on near-shore marine ecosystems on islands within the San Juan archipelago, Washington, we surveyed for the presence or non-detection of predatory mammals on a subset of 14 uninhabited islands: 10 that are part of the San Juan Islands National Wildlife Refuge, 3 that are managed by the Bureau of Land Management (BLM), and 1 that is owned by The Nature Conservancy (TNC). We were unable to detect invasive terrestrial mammals on any of the 14 islands. We found native mice (Peromyscus maniculatus) and voles (Microtus townsendi) on one island each, and native raccoons (Procyon lotor pacifica) on three islands. We speculate that the nearly ubiquitous presence of native river otters (Lontra canadensis) along with native predatory birds may be preventing immigrant invasive mammals (primarily house mice [Mus musculus] and rats [Rattus spp.]) from gaining a foot-hold on the islands. Inadequate habitat and/or island size and distance from larger islands and their source populations along with insufficient trap nights may also have contributed to the non-detection of small mammals on the islands we surveyed. For the best chance at keeping these islands free of invaders, we recommend future surveys using continuous measurement methods (e.g., track plates and monitoring blocks) for early detection of future invasions.