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Northwestern United States (northwestern + united_states)
Selected AbstractsThe Late Prehistoric,Early Historic Game Sink in the Northwestern United StatesCONSERVATION BIOLOGY, Issue 1 2002R. Lee Lyman The number of big game killed by the Corps of Discovery in 1805,1806 and recorded by Lewis and Clark suggests that ungulates were abundant in central and eastern Montana and rare in western Montana, central Idaho, and southeastern Washington during the early nineteenth century. Paleoecologists Paul Martin and Chris Szuter conclude that this difference was a function of human predation. They support their conclusion that ungulates would have been abundant in southeastern Washington had humans not hunted them by arguing that the nineteenth-century livestock industry was successful without supplemental feeding. The livestock industry was, however, not consistently successful until artificial feeding was initiated. Archaeological data from eastern Washington indicate that ungulates have been taken by human hunters more frequently than small-mammal prey throughout the last 10,000 years and that ungulates decreased relative to small mammals coincident with changes in climate. Bison ( Bison bison) and elk (Cervus canadensis) were present in eastern Washington throughout the Holocene, but bison were abundant there only during a cooler and moister period; elk have been abundant only in the twentieth century, subsequent to transplants and the extermination of predators. Geographic variation in the abundance of bison across Montana, Idaho, and eastern Washington has been influenced by human predation but has also been influenced by biogeographic history, habitat differences, and climatic change. Resumen: Los datos históricos proveen información valiosa sobre las estructuras de los ecosistemas, sus funciones y procesos. El número de animales de caza grandes que fueron sacrificados por las tropas de descubrimiento en 1805-1806 y registradas por Lewis y Clark sugieren que los ungulados eran abundantes en Montana central y oriental y raros en Montana occidental, Idaho central y el sudeste de Washington durante los inicios del siglo diecinueve. Los paleontólogos Paul Martin y Chris Szuter concluyen que esta diferencia fue causada por la depredación humana. Ellos apoyan su conclusión de que los ungulados podrían haber sido abundantes en el sudeste de Washington si los humanos no los hubieran cazado argumentando que la industria de la ganadería del siglo diecinueve exitosa sin alimento suplementario. Sin embargo, la industria de la ganadería no fue consistentemente exitosa hasta que se inició la alimentación artificial. Los datos arqueológicos de Washington oriental indican que los ungulados fueron eliminados por los cazadores humanos mas frecuentemente que las presas pequeñas de mamíferos a lo largo de los últimos 10,000 años y que la disminución de ungulados, relativa a la de mamíferos pequeños coincidió con cambios en el clima. El bisonte (Bison bison) y el alce (Cervus canadiensis) estuvieron presentes en Washington oriental a lo largo del Holoceno, pero los bisontes fueron abundantes solo durante un periodo mas frío y húmedo; los alces habían sido abundantes solo en el siglo veinte subsecuente a los transplantes y a la exterminación de los depredadores. La variación en la abundancia de alces a lo largo de Montana, Idaho y el oriente de Washington estuvo influenciada por la depredación humana, pero también por la historia biogeográfica, las diferencias en hábitat y el cambio climático. [source] Isolation and characterization of nine microsatellite markers for Brachypodium sylvaticum (Huds.) Beauv., a recently invasive grass species in OregonMOLECULAR ECOLOGY RESOURCES, Issue 6 2008ALISA P. RAMAKRISHNAN Abstract The patterns of genetic diversity caused by rapid range expansions following recent colonizations are best observed using highly polymorphic genetic markers. We characterized nine microsatellite markers for Brachypodium sylvaticum, a bunchgrass invasive in the Northwestern United States and native to Eurasia. Loci exhibited from two to 10 alleles, and generally had high FIS values. These loci will help identify sources of new populations in the region, and they will be useful for studying patterns of genetic diversity during rapid range expansions. [source] Relationship between stream temperature, thermal refugia and rainbow trout Oncorhynchus mykiss abundance in arid-land streams in the northwestern United StatesECOLOGY OF FRESHWATER FISH, Issue 1 2001J. L. Ebersole Abstract , Warm stream temperatures may effectively limit the distribution and abundance of Pacific salmon Oncorhynchus spp. in streams. The role of cold thermal refugia created by upwelling groundwater in mediating this effect has been hypothesized but not quantitatively described. Between June 21 and September 15, 1994, rainbow trout O. mykiss abundance within 12 northeast Oregon (USA) stream reaches was inversely correlated with mean ambient maximum stream temperatures (r=,0.7, P<0.05). Some rainbow trout used thermal refugia (1,10 m2 surface area) that were on average 3,8°C colder than ambient stream temperatures. Within the warmest reaches, high ambient stream temperatures (>22°C) persisted from mid-June through August, and on average 10,40% of rainbow trout were observed within thermal refugia during periods of midday maximum stream temperatures. Frequency of cold-water patches within reaches was not significantly associated with rainbow trout density after accounting for the influence of ambient stream temperature (P=0.06; extra sum of squares F -test). Given prolonged high ambient stream temperatures in some reaches, the thermal refugia available in the streams we examined may be too small and too infrequent to sustain high densities of rainbow trout. However, these refugia could allow some rainbow trout to persist, although at low densities, in warm stream reaches. [source] The Role of Social Support in Facilitating Postpartum Women's Return to EmploymentJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 5 2005Marcia Gruis Killien Purpose: More than half of mothers with infants under 1 year are employed. This study explored the role of social support in facilitating women's return to employment during the 1st year postpartum. Design: Analysis of existing longitudinal, repeated-measures questionnaire data gathered at 4 and 12 months postpartum. Participants: 94 postpartum women who were married or partnered, employed, and residing in a large urban area in the northwestern United States. Outcome Measures: Satisfaction with decision to return to work, role performance, work-family balance. Results: Relationships between indicators of social support and return-to-work experiences were absent to modest. Satisfaction with child care was related to satisfaction with the decision to return to work. Workplace support was related to work-family balance at 12 months postpartum. Conclusions: Satisfactory child care arrangements and supportive relationships in the workplace are the most significant facilitators of women's return to work postpartum. [source] Breaking New Ground in Juvenile Justice Settings: Assessing for Competencies in Juvenile OffendersJUVENILE AND FAMILY COURT JOURNAL, Issue 2 2005JULIETTE R. MACKIN ABSTRACT The field of juvenile justice has made great strides in developing a research base of effective practices and principles, including an understanding of risk factors and needs that contribute to juvenile offending. However, the research base and practice of systematic assessment has not yet fully incorporated youth, family, and community strengths. To address this need, three juvenile justice agencies in the northwestern United States participated in a pilot study to develop and implement an assessment tool (the Youth Competency Assessment) and process that would identify and utilize strengths to help balance the risk and needs focus of their assessment and case planning practices. This article provides descriptions and implementation strategies of the three pilot sites. The article concludes with recommended system changes and policy interventions to support ongoing utilization of this kind of strength-based tool in juvenile justice settings, and a clear set of recommendations for other communities wishing to implement strength-based assessment in their own agencies. [source] Pushing north one bottleneck at a time: site frequency spectra tell the history of Sitka spruceMOLECULAR ECOLOGY, Issue 18 2010ARMANDO GERALDES Reconstructing the history of populations is a longstanding goal of molecular ecologists. In addition to a better understanding of the past, it is hoped that this knowledge would also facilitate predictions regarding species' responses to future events such as climate change. The traditional way of doing this is through the fossil record, but these historical records are often incomplete. Inferring historical demography from patterns of nucleotide variability can help to fill these gaps. In this issue of Molecular Ecology, Holliday et al. (2010) glimpse into the demographic past of Sitka spruce, Picea sitchensis, an economically and ecologically important species native to northwestern United States and Canada, by examining the site frequency spectrum (SFS) of 153 loci in six populations covering the species entire range. [source] | ||||||||||