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Johnson R.C.,Washington State University | Erickson V.J.,Pacific Northwest Region | Mandel N.L.,Pacific Northwest Research Station | Bradley St Clair J.,Pacific Northwest Research Station | Vance-Borland K.W.,The Conservation Planning Institute
Botany | Year: 2010

Seed transfer zones ensure that germplasm selected for restoration is suitable and sustainable in diverse environments. In this study, seed zones were developed for mountain brome (Bromus carinatus Hook. & Arn.) in the Blue Mountains of northeastern Oregon and adjoining Washington. Plants from 148 Blue Mountain seed source locations were evaluated in common-garden studies at two contrasting test sites. Data on phenology, morphology, and production were collected over two growing seasons. Plant traits varied significantly and were frequently correlated with annual precipitation and annual maximum temperature at seed source locations (P < 0.05). Plants from warmer locations generally had higher dry matter production, longer leaves, wider crowns, denser foliage, and greater plant height than those from cooler locations. Regression models of environmental variables with the first two principal components (PC 1 and PC 2) explained 46% and 40% of the total variation, respectively. Maps of PC 1 and PC 2 generally corresponded to elevation, temperature, and precipitation gradients. The regression models developed from PC 1 and PC 2 and environmental variables were used to map seed transfer zones. These maps will be useful in selecting mountain brome seed sources for habitat restoration in the Blue Mountains. Source

Researchers found evidence that the invasive barred owl is playing a pivotal role in the continued decline of spotted owls, although habitat loss and climate variation were also important in some parts of the species range. Barred owls compete with spotted owls for space, food and habitat. This research indicated that since monitoring began spotted owl populations declined 55-77 percent in Washington, 31-68 percent in Oregon and 32-55 percent in California. In addition, population declines are now occurring on study areas in southern Oregon and northern California that were previously experiencing little to no detectable decline through 2009. Dr. Katie Dugger, a research biologist at the USGS Oregon Cooperative Fish and Wildlife Research Unit, Oregon State University and lead author on the report, said that "This study provides strong evidence that barred owls are negatively affecting spotted owl populations. The presence of barred owls was associated with decreasing spotted owl survival rates in some study areas and spotted owls were disappearing from many of their historical breeding territories as those areas were invaded by barred owls." The exception was a small area in California where barred owl removals began in 2009, and where long-term population declines were only 9 percent. Spotted owl populations and survival rates have increased on the latter area since the removal of barred owls started. However, further research on barred owl removal is required in other parts of the spotted owl's range—especially in Washington, where barred owl numbers have been high for a long time. Additionally, said Dugger, "The amount of suitable habitat required by spotted owls for nesting and roosting is important because spotted owl survival, colonization of empty territories, and number of young produced tends to be higher in areas with larger amounts of suitable habitat, at least on some study areas." Relationships between spotted owl populations and climate was complex and variable, but rangewide, the study results suggested that survival of young spotted owls and their ability to become part of the breeding population increased when winters were drier. This may become a factor in population numbers in the future, given climate change predictions for the Pacific Northwest include warmer, wetter winters. The collaborative team of 37 researchers analyzed data from 11 study areas that represented 9 percent of the spotted owl range. During the study, field crews monitored how many owls inhabited different territories, and the yearly survival and reproductive success of banded spotted owls. "This type of collaborative research focused on specific management and conservation objectives provides important information for resource managers and policy decision-makers who manage public resources," said Eric Forsman, a coauthor on the study at the USDA Forest Service, Pacific Northwest Research Station. The paper, "The effects of habitat, climate and barred owls on long-term demography of northern spotted owls," was published in The Condor: Ornithological Applications and authored by Katie M. Dugger, USGS, Oregon Cooperative Fish and Wildlife Research Unit, Oregon State University Department of Fisheries and Wildlife; Eric D. Forsman, USDA Forest Service, Pacific Northwest Research Station; Alan B. Franklin, USDA APHIS National Wildlife Research Center; Raymond Davis, USDA Forest Service, Pacific Northwest Region, and 33 others. Although they do occur in young forests in some areas, northern spotted owls are strongly associated with old forest in most of their range. The U.S. Fish and Wildlife Service listed the northern spotted owl as threatened in 1990 because of the declines in old-growth forest habitat throughout its range in Washington, Oregon and northern California. Explore further: US advances plan to kill barred owls in Northwest

Lesher R.D.,Pacific Northwest Region | Henderson J.A.,Pacific Northwest Region
USDA Forest Service - General Technical Report PNW-GTR | Year: 2010

The ecology and distribution of western redcedar (Thuja plicata) and Alaska yellowcedar (Callitropsis nootkatensis, syn Chamaecyparis nootkatensis) were analyzed based on their occurrence and abundance on 5587 USFS ecology plots on National Forest lands in northwestern Washington. Western redcedar occurred on 40% of the plots, Alaska yellowcedar occurred on 10% of the plots. The ecology is described for these species relative to environmental gradients of elevation, temperature and moisture. Redcedar showed broad ecological amplitude, but was more frequent at lower elevations, warmer temperatures, and towards the drier end of the precipitation gradient, whereas yellowcedar was limited to cooler sites at mid to upper elevations and higher precipitation. The role of these cedars in forest succession and stand development is described based on their abundance and size-class distribution in different stand ages. Source

Henderson J.A.,Pacific Northwest Region | Lesher R.D.,Pacific Northwest Region | Peter D.H.,Pacific Northwest Research Station | Ringo C.D.,Pacific Northwest Region
USDA Forest Service - General Technical Report PNW-GTR | Year: 2012

A gradient-analysis-based model and grid-based map are presented that use the potential vegetation zone as the object of the model. Several new variables are presented that describe the environmental gradients of the landscape at different scales. Boundary algorithms are conceptualized, and then defined, that describe the environmental boundaries between vegetation zones on the Olympic Peninsula, Washington, USA. The model accurately predicted the vegetation zone for 76.4 percent of the 1,497 ecoplots used to build the model. Independent plot sets used to validate the model had an accuracy of 82.1 percent on national forest land, and 71.8 percent on non-national-forest land. This study demonstrated that a model based on boundary algorithms can be an alternative to regression-based models for predicting landscape vegetation patterns. Potential applications of the model and use of the environmental gradients to address ecological questions and resource management issues are presented. Source

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