Short-distance (i.e., < 100 km) introductions of diminutive fish species are often not well documented but may have important ecological consequences. Prickly sculpin (Cottus asper), which are native to lowland habitats of the Pacific Northwest, have been introduced in some mountain lakes of western Washington State. The ecology of six introduced populations of prickly sculpin was investigated through daytime minnow trapping, diet analysis, and age and growth analysis. Results of minnow trapping indicated prickly sculpin were abundant in each lake (Nisqually River lakes, mean = 11.3 individuals/trap; Dry Bed Lakes in Satsop River basin, mean = 1.9 individuals/trap). Prickly sculpin diet in the Nisqually River lakes was composed primarily of micro-crustaceans (92% by number of all prey items; dominated by copepods and cladocerans), chironomids, mollusks, and sculpin In the Dry Bed Lakes, the diet was composed primarily of caddisflies, oligochaetes, and micro-crustaceans. In native lentic habitats, prickly sculpin primarily consume macroinvertebrates with the rare occurrence of micro-crustaceans in the diet. Similar to native populations, prickly sculpin in the mountain lakes reached sizes greater than 150 mm total length; however, their growth rates were slower. In conclusion, prickly sculpin were common in the mountain lakes, consumed a variety of prey types and sizes, and grew to a relatively large size; therefore, this species may have important effects on the ecosystem of these lakes. However, additional assessment of their native and introduced distribution and ecology is needed to better understand their potential as an invasive species.

Mountain hemlock growth chronologies were used to reconstruct the mass balance of South Cascade Glacier, an alpine glacier in the North Cascade Range of Washington State. The net balance reconstruction spans 350 years, from 1659 to 2009. Summer and winter balances were reconstructed for 1346–2009 and 1615–2009, respectively. Relationships between mass balance and winter precipitation, temperature, the Pacific Decadal Oscillation index, and the El Niño Southern Oscillation index indicate that these influence glacier balance at various temporal scales. Above-average net, summer, and winter mass balance occurred mainly in 1690–1710, 1810–1820, 1845–1860, 1865–1890, and 1975–1990, and below-average balance periods include 1680–1690, 1790–1810, 1820–1840, and 1930–1960. Above- and below-average reconstructed mass balances at South Cascade Glacier were concurrent with similar periods from other glacier balance reconstructions in the Pacific Northwest region of North America. Agreement among these records suggests that changes in South Cascade Glacier mass balance are good indicators of regional balance fluctuations, and glaciers in the Pacific Northwest are responding similarly to regional external forcings. The current rate of decline, from 2000 to 2009, in the reconstructed balance record has been faster than any decline in a century. This decreasing trend is projected to continue with increasing temperatures, and will likely affect glacier-influenced water resources in the Pacific Northwest.

We gathered baseline data to assess alder tree damage in western Oregon riparian ecosystems. We sought to determine if Phytophthora-type cankers found in Europe or the pathogen Phytophthora alni subsp. alni, which represent a major threat to alder forests in the Pacific Northwest, were present in the study area. Damage was evaluated in 88 transects; information was recorded on damage type (pathogen, insect or wound) and damage location. We evaluated 1445 red alder (Alnus rubra), 682 white alder (Alnus rhombifolia) and 181 thinleaf alder (Alnus incana spp. tenuifolia) trees. We tested the correlation between canopy dieback and canker symptoms because canopy dieback is an important symptom of Phytophthora disease of alder in Europe. We calculated the odds that alder canopy dieback was associated with Phytophthora-type cankers or other biotic cankers. P. alni subsp. alni (the causal agent of alder disease in Europe) was not identified in western Oregon; however, Phytophthora siskiyouensis was isolated from Phytophthora-type cankers which were present on 2% of red alder trees and 3% of white alder trees. The odds of canopy dieback were 5.4 and 4.8 times greater for red and white alder (respectively) with Phytophthora-type canker symptoms than in trees without such cankers. The percentage of trees with canopy dieback was 51%, 32%, and 10% for red, white, and thinleaf alder respectively. Other common damage included wounding, foliar pathogens and insects on red alder. This is the first report of Phytophthora canker of alder in United States forests and first report of P. siskiyouensis isolation from alder in forests anywhere.

Plant invasions have the potential to disrupt community dynamics and impair essential ecosystem services, including the pollination of native flowers. Invaders most likely to invoke pollinator competition are characterized by conspicuous, resource-rich blooms and long flowering periods, while the natives most likely to be impacted are obligate out-crossers that are sensitive to disturbance or locally rare. We investigated the effects of a widespread showy invader of the Pacific Northwest, Rubus armeniacus (Himalayan blackberry), on an imperiled endemic wildflower, Sidalcea hendersonii. We observed pollinators, quantified pollen deposition and conducted pollen-supplementation experiments on S. hendersonii plants growing at three distances (1 m, 15 m and 50 m) from well-established blackberry patches in five adjacent field plots. Individual R. armeniacus flowers received more than three times as many total visits as S. hendersonii inflorescences; however, there was minimal overlap between the pollinator assemblages visiting the two species. R. armeniacus pollen was present on 67% of S. hendersonii stigmas; however, there was no significant relationship between distance and invasive pollen deposition or distance and natural seed set. Pollen-supplementation experiments revealed that S. hendersonii was moderately pollen-limited at all distances, and reproductive output was actually higher at the distance treatment closest to the invader, suggesting a positive proximity effect unrelated to pollination. Thus, although inconstant pollinator foraging and prodigious heterospecific pollen deposition suggest R. armeniacus influences pollinator interactions, it does not appear that the invader directly limits the reproductive success of S. hendersonii.

Biotic and abiotic factors influence fish populations and distributions. Concerns have been raised about the influence of hatchery fish on wild populations. Carson National Fish Hatchery produces spring Chinook salmon Oncorhynchus tshawytscha in the Wind River, Washington, and some spawn in the river. Managers were concerned that Chinook salmon could negatively affect wild steelhead O. mykiss and that a self-sustaining population of Chinook salmon may develop. Our objectives were to assess: 1) the distribution and populations of juvenile spring Chinook salmon and juvenile steelhead in the upper Wind River; 2) the influence of stream flow and of each population on the other; and 3) if Chinook salmon populations were self-sustaining. We snorkeled to determine distribution and abundance. Flow in the fall influenced upstream distribution and abundance of juvenile Chinook salmon. Juvenile Chinook salmon densities were consistently low (range 0.0 to 5.7 fish 100 m^-2) and not influenced by number of spawners, winter flow magnitude, or steelhead abundance. Juvenile steelhead were distributed through the study section each year. Age-0 and age-1 steelhead densities (age-0 range: 0.04 to 37.0 fish 100 m^-2; age-1 range: 0.02 to 6.21 fish 100 m^-2) were consistently higher than for juvenile Chinook salmon. Steelhead spawner abundance positively influenced juvenile steelhead abundance. During this study, Chinook salmon in the Wind River appear to have had little effect on steelhead. Low juvenile Chinook salmon abundance and a lack of a spawner-to-juvenile relationship suggest Chinook salmon are not self-sustaining and potential for such a population is low under current conditions.

We evaluated the two-year effects of variable-retention harvest on chipmunk (Tamias spp.) abundance () and habitat in mature coniferous forests in western Oregon and Washington because wildlife responses to density/pattern of retained trees remain largely unknown. In a randomized complete-block design, six treatments were applied to 13-ha units at three sites (blocks): four retention levels of original basal area (BA) in an aggregated tree pattern (100, 75, 40, and 15%) and two retention levels in a dispersed tree pattern (15 and 40%). Log-yarding method differed at each site (suspension cable, shovel-loader, or helicopter). We used an information-theoretic approach to compare six candidate regression models for their ability to predict treatment responses of chipmunk and associated habitat variables. Chipmunk had a positive linear relationship with retention level that predicted a 50% reduction in abundance as % BA retention decreased from 100 to 15% (R² = 0.36). Disturbed soil cover was strongly related to the interaction of retention level and block (i.e., yarding method and other site-level differences) (R² = 0.82), and the model predicted disproportionately greater disturbed area for cable yarding (16%) than for shovel (10%) or helicopter (6%) methods as retention decreased from 100 to 15%. Chipmunk had a negative linear relationship with disturbed soil cover that predicted a 70% reduction in the species' abundance as disturbed area increased from 0 to 16% (R² = 0.53). Retention level and yarding method are important considerations when planning harvesting operations because of their potential impacts to small mammal populations.

Increments of a fish otolith are commonly used to estimate age and somatic growth; yet the accuracy of such estimates first requires an understanding of the periodicity with which increments are formed. We conducted a rearing experiment to evaluate daily formation of increments in otoliths from spring Chinook salmon (Oncorhynchus tshawytscha), an anadromous fish from the Yakima River, Washington. Specifically, we compared the known number of post-emergence days that fish were alive to the number of otolith increments formed after an emergence check. Our results indicated daily formation of otolith increments, thus corroborating previous studies and supporting the use of otolith increments to estimate age and somatic growth of individual Chinook salmon. Given the positive relationship between body size and survival to adulthood, continued use of otolith microstructure to quantify age and growth will help identify factors critical for the recovery of listed Chinook salmon populations.