Influence of landscape on resident and anadromous life history types of Oncorhynchus mykiss

2008 ◽  
Vol 65 (6) ◽  
pp. 1013-1023 ◽  
Author(s):  
Shawn R. Narum ◽  
Joseph S. Zendt ◽  
David Graves ◽  
William R. Sharp
Keyword(s):  
Life History ◽  
Oncorhynchus Mykiss ◽  
Pacific Northwest ◽  
Isolation By Distance ◽  
High Elevation ◽  
Steelhead Trout ◽  
Mantel Tests ◽  
Lower Elevation ◽  
The Pacific ◽  
High Gradients

Landscape features can significantly influence genetic and life history diversity of rainbow/steelhead trout, Oncorhynchus mykiss . In this study, heterozygosity of 21 populations of O. mykiss from the Pacific Northwest, USA, was significantly negatively correlated with features such as elevation (P = 0.0023), upstream distance (P = 0.0129), and precipitation (P = 0.0331), and positively correlated with temperature (P = 0.0123). Mantel tests of isolation by distance were significant for anadromous populations (P = 0.007) but not for resident collections (P = 0.061), and suggested that fluvial distance was not the only significant physical variable that influenced genetic structure of life history types. Principal components interpolated to the drainage indicated that high-elevation sites were primarily occupied by the resident form, and high gradients and barriers act to limit anadromous distribution to lower elevation sites. These patterns of O. mykiss life history diversity provide insight regarding the interaction, distribution, and limitations of resident and anadromous forms of the species within this region.

Ecohydrological analysis of Steelhead (Oncorhynchus mykiss) habitat in an effluent dependent stream in the Pacific Northwest, USA

Ecohydrology ◽  
2013 ◽  
Vol 7 (2) ◽  
pp. 557-568 ◽  
Author(s):  
R. Sánchez-Murillo ◽  
E.S. Brooks ◽  
L. Sampson ◽  
J. Boll ◽  
F. Wilhelm
Keyword(s):  
Oncorhynchus Mykiss ◽  
Pacific Northwest ◽  
The Pacific

Precipitation chemistry and deposition at a high-elevation site in the Pacific Northwest United States (1989–2015)

2019 ◽  
Vol 212 ◽  
pp. 221-230 ◽  
Author(s):  
Anne M. Johansen ◽  
Clint Duncan ◽  
Ashleen Reddy ◽  
Naomi Swain ◽  
Mari Sorey ◽  
...  
Keyword(s):  
United States ◽  
Pacific Northwest ◽  
Precipitation Chemistry ◽  
High Elevation ◽  
High Elevation Site ◽  
The Pacific

Spatially overlapping salmon species have varied population response to early life history mortality from increased peak flows

2021 ◽  
pp. 1-10
Author(s):  
Colin L. Nicol ◽  
Jeffrey C. Jorgensen ◽  
Caleb B. Fogel ◽  
Britta Timpane-Padgham ◽  
Timothy J. Beechie
Keyword(s):  
Climate Change ◽  
Life History ◽  
Pacific Northwest ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Early Life History ◽  
Climate Change Scenarios ◽  
Peak Flows ◽  
Multi Stage ◽  
The Pacific

In the Pacific Northwest, USA, climate change is expected to result in a shift in average hydrologic conditions and increase variability. The relative vulnerabilities to peak flow changes among salmonid species within the same basin have not been widely evaluated. We assessed the impacts of predicted increases in peak flows on four salmonid populations in the Chehalis River basin. Coupling observations of peak flows, emissions projections, and multi-stage Beverton–Holt matrix-type life cycle models, we ran 100-year simulations of spawner abundance under baseline, mid-century, and late-century climate change scenarios. Coho (Oncorhynchus kisutch) and spring Chinook salmon (Oncorhynchus tshawytscha) shared the highest projected increase in interannual variability (SD = ±15%). Spring Chinook salmon had the greatest reduction in median spawner abundance (–13% to –15%), followed by coho and fall Chinook salmon (–7% to –9%), then steelhead (Oncorhynchus mykiss) (–4%). Our results show that interspecies and life history variability within a single basin is important to consider. Species with diverse age structures are partially buffered from population variability, which may increase population resilience to climate change.

Life-history studies of ferns: a consideration of perspective

1985 ◽  
Vol 86 ◽  
pp. 371-380 ◽  
Author(s):  
Michael I. Cousens ◽  
Deborah Grimm Lacey ◽  
Eugene M. Kelly
Keyword(s):  
Life History ◽  
Pacific Northwest ◽  
Habitat Type ◽  
Life Forms ◽  
Safe Sites ◽  
Blechnum Spicant ◽  
The Pacific ◽  
Onoclea Sensibilis ◽  
Lygodium Japonicum ◽  
History Classes

SynopsisAutecology of pteridophytes may be refined by defining the plant community and habitat, and phytogeographic occurrence, of the species studied. Work withBlechnum spicantin the Pacific Northwest, and withLorinserea areolatain the Southeastern U.S.A. has uncovered autecological differences for these species across habitats differing in overstory and hydrology. Natural history observations are necessary to suggest the most appropriate hypotheses to investigate objectively. A modification of Daubenmire's Canopy-Coverage method provides a grid across which many factors may be recorded or tested in repeatable objective manner. Such an analysis was used to test the association betweenL. areolatalife-history classes and hummocks in hardwood swamps. Contingency tables were used to disprove the null hypothesis thatL. areolatawas distributed randomly with regard to hummocks. Hummocks were thus ‘safe sites’ for the completion of the life-cycle ofL. areolata, and additional considerations of safe sites forLygodium japonicumandDryopteris ludovicianaare introduced. Analysis of biomass and coverage ofOnoclea sensibiliswhere it is very abundant suggests that it is highly susceptible to competition where it shares plots withL. areolata.The concept of the optimum habitat with regard to abundance of the taxon, frequency of the habitat-type, successful reproduction, and susceptibility to competition between similar life forms is discussed.

Contrasting Climatic Histories for the Snake River Plain, Idaho, Resulting from Multiple Thermal Maxima

1986 ◽  
Vol 26 (3) ◽  
pp. 321-339 ◽  
Author(s):  
Owen K. Davis ◽  
John C. Sheppard ◽  
Susan Robertson
Keyword(s):  
Pacific Northwest ◽  
Late Quaternary ◽  
High Elevation ◽  
Snake River Plain ◽  
Early Holocene ◽  
Snake River ◽  
Limiting Factor ◽  
Summer Drought ◽  
The Pacific ◽  
River Plain

Ten sites near the Snake River Plain have consistent differences in their climatic histories. Sites at low elevation reflect the “early Holocene xerothermic” of the Pacific Northwest, whereas most climatic chronologies at high elevation indicate maximum warmth or aridity somewhat later, ca. 6000 yr ago. This elevational contrast in climatic histories is duplicated at three sites from the central Snake River Plain. For sites in such close proximity, the different chronologies cannot be explained by changes in atmospheric circulation during the late Quaternary. Rather, the differences are best explained by the autecology of the plants involved and the changing seasonal climate. The seasonal climatic sequence predicted by multiple thermal maxima explains the high- and low-elevation chronologies. During the early Holocene, maximum insolation and intensified summer drought in July forced low-elevation vegetation upward. However, moisture was not a limiting factor at high elevation, where vegetation moved upward in response to increased length of growing season coincident with maximum September insolation 6000 yr ago.

scholarly journals Impacts of the July 2012 Siberian fire plume on air quality in the Pacific Northwest

2017 ◽  
Vol 17 (4) ◽  
pp. 2593-2611 ◽  
Author(s):  
Andrew D. Teakles ◽  
Rita So ◽  
Bruce Ainslie ◽  
Robert Nissen ◽  
Corinne Schiller ◽  
...  
Keyword(s):  
British Columbia ◽  
Air Quality ◽  
Pacific Northwest ◽  
Quality Standards ◽  
High Elevation ◽  
Monitoring Site ◽  
Smoke Plume ◽  
Air Quality Standards ◽  
The Pacific ◽  
Modis Aod

Abstract. Biomass burning emissions emit a significant amount of trace gases and aerosols and can affect atmospheric chemistry and radiative forcing for hundreds or thousands of kilometres downwind. They can also contribute to exceedances of air quality standards and have negative impacts on human health. We present a case study of an intense wildfire plume from Siberia that affected the air quality across the Pacific Northwest on 6–10 July 2012. Using satellite measurements (MODIS True Colour RGB imagery and MODIS AOD), we track the wildfire smoke plume from its origin in Siberia to the Pacific Northwest where subsidence ahead of a subtropical Pacific High made the plume settle over the region. The normalized enhancement ratios of O3 and PM1 relative to CO of 0.26 and 0.08 are consistent with a plume aged 6–10 days. The aerosol mass in the plume was mainly submicron in diameter (PM1 ∕ PM2.5 = 0.96) and the part of the plume sampled at the Whistler High Elevation Monitoring Site (2182 m a.s.l.) was 88 % organic material. Stable atmospheric conditions along the coast limited the initial entrainment of the plume and caused local anthropogenic emissions to build up. A synthesis of air quality from the regional surface monitoring networks describes changes in ambient O3 and PM2.5 during the event and contrasts them to baseline air quality estimates from the AURAMS chemical transport model without wildfire emissions. Overall, the smoke plume contributed significantly to the exceedances in O3 and PM2.5 air quality standards and objectives that occurred at several communities in the region during the event. Peak enhancements in 8 h O3 of 34–44 ppbv and 24 h PM2.5 of 10–32 µg m−3 were attributed to the effects of the smoke plume across the Interior of British Columbia and at the Whistler Peak High Elevation Site. Lesser enhancements of 10–12 ppbv for 8 h O3 and of 4–9 µg m−3 for 24 h PM2.5 occurred across coastal British Columbia and Washington State. The findings suggest that the large air quality impacts seen during this event were a combination of the efficient transport of the plume across the Pacific, favourable entrainment conditions across the BC interior, and the large scale of the Siberian wildfire emissions. A warming climate increases the risk of increased wildfire activity and events of this scale reoccurring under appropriate meteorological conditions.

scholarly journals Screening of Predatory Mites as Potential Control Agents of Pest Mites in Landscape Plant Nurseries of the Pacific Northwest

2000 ◽  
Vol 18 (4) ◽  
pp. 218-223
Author(s):  
P.D. Pratt ◽  
B.A. Croft
Keyword(s):  
Biological Control ◽  
Life History ◽  
Pacific Northwest ◽  
Spider Mite ◽  
Life History Traits ◽  
Predatory Mites ◽  
Spider Mites ◽  
Landscape Plant ◽  
Landscape Plants ◽  
The Pacific

Abstract To select a biological control agent for suppression of spider mites on landscape plants in western regions of the Pacific Northwest, we compared life history traits of Galendromus occidentalis Nesbitt, Neoseiulus californicus (McGregor) and Neoseiulus fallacis (Garman). We also evaluated abilities of these predatory mites to suppress spider mites in 4 landscape plant species under field conditions. Comparing life history traits from the literature, intrinsic rate of increase was similar between the 2 Neoseiulus species but lower for G. occidentalis. Prey killed per day was greatest for G. occidentalis > N. fallacis > N. californicus. For overwintering abilities, N. fallacis and G. occidentalis are indigenous to the Pacific Northwest and will survive winter assuming overwintering sites are available, but survival of N. californicus is unlikely. Neoseiulus californicus has the widest prey range, G. occidentalis the narrowest, with N. fallacis intermediate. When inoculated into spider mite infested landscape plants, N. fallacis was equally effective at suppressing spider mites as G. occidentalis in either Malus rootstock or Acer shade trees. Further tests with N. fallacis or N. californicus on Spiraea and Rhododendron plants suggested that N. fallacis is equally or more effective at suppressing pest mites, respectively. Compared with the other candidates, N. fallacis was equally effective at controlling pest mites and has a wider prey range than G. occidentalis. Neoseiulus fallacis appears to be the best candidate for biological control of multiple spider mite species on landscape plants in these parts of the Pacific Northwest.

Sign in / Sign up

Export Citation Format

Share Document