600 State Street
600 State Street
Davis R.,U.S. Department of Agriculture |
Yang Z.,Oregon State University |
Yost A.,600 State Street |
Belongie C.,U.S. Department of Agriculture |
Cohen W.,U.S. Department of Agriculture
Forest Ecology and Management | Year: 2017
We modeled the normal fire environment for occurrence of large forest wildfires (>40 ha) for the Pacific Northwest Region of the United States. Large forest wildfire occurrence data from the recent climate normal period (1971–2000) was used as the response variable and fire season precipitation, maximum temperature, slope, and elevation were used as predictor variables. A projection of our model onto the 2001–2030 climate normal period showed strong agreement between model predictions and the area of forest burned by large wildfires from 2001 to 2015 (independent fire data). We then used downscaled climate projections for two greenhouse gas concentration scenarios and over 30 climate models to project changes in environmental suitability for large forest fires over the 21st century. Results indicated an increasing proportion of forested area with fire environments more suitable for the occurrence of large wildfires over the next century for all ecoregions but less pronounced for the Coast Range and Puget Lowlands. The largest increases occurred on federal lands, while private and state lands showed less. We calculated fire rotation periods for the recent historical and current climate and examined the relative differences between them and our modeled large wildfire suitability classes. By the end of the century, the models predicted shorter fire rotation periods, with cooler/moister forests experiencing larger magnitudes of change than warmer/drier forests. Modeling products, including a set of time series maps, can provide forest resource managers, fire protection agencies, and policy-makers empirical estimates of how much and where climate change might affect the geographic distribution of large wildfires and effect fire rotations. © 2017
Klocko A.L.,Oregon State University |
Meilan R.,Purdue University |
James R.R.,Utah State University |
Viswanath V.,Global Institute of Intellectual Property GIIP |
And 7 more authors.
Canadian Journal of Forest Research | Year: 2014
The stability and value of transgenic pest resistance for promoting tree growth are poorly understood. These data are essential for determining if such trees could be beneficial to commercial growers in the face of substantial regulatory and marketing costs. We investigated growth and insect resistance in hybrid poplar expressing the cry3Aa transgene in two field trials. An initial screening of 502 trees comprising 51 transgenic gene insertion events in four clonal backgrounds (Populus trichocarpa × Populus deltoides, clones 24-305, 50-197, and 198-434; and P. deltoides × Populus nigra, clone OP-367) resulted in transgenic trees with greatly reduced insect damage. A large-scale study of 402 trees from nine insertion events in clone OP-367, conducted over two growing seasons, demonstrated reduced tree damage and significantly increased volume growth (mean 14%). Quantification of Cry3Aa protein indicated high levels of expression, which continued after 14 years of annual or biannual coppice in a clone bank. With integrated management, the cry3Aa gene appears to be a highly effective tool for protecting against leaf beetle damage and improving yields from poplar plantations.
Ager A.A.,U.S. Department of Agriculture |
Finney M.A.,U.S. Department of Agriculture |
Mcmahan A.,U.S. Department of Agriculture |
Cathcart J.,600 State Street
Natural Hazards and Earth System Science | Year: 2010
Wildfire simulation modelling was used to examine whether fuel reduction treatments can potentially reduce future wildfire emissions and provide carbon benefits. In contrast to previous reports, the current study modelled landscape scale effects of fuel treatments on fire spread and intensity, and used a probabilistic framework to quantify wildfire effects on carbon pools to account for stochastic wildfire occurrence. The study area was a 68 474 ha watershed located on the Fremont-Winema National Forest in southeastern Oregon, USA. Fuel reduction treatments were simulated on 10% of the watershed (19% of federal forestland). We simulated 30 000 wildfires with random ignition locations under both treated and untreated landscapes to estimate the change in burn probability by flame length class resulting from the treatments. Carbon loss functions were then calculated with the Forest Vegetation Simulator for each stand in the study area to quantify change in carbon as a function of flame length. We then calculated the expected change in carbon from a random ignition and wildfire as the sum of the product of the carbon loss and the burn probabilities by flame length class. The expected carbon difference between the non-treatment and treatment scenarios was then calculated to quantify the effect of fuel treatments. Overall, the results show that the carbon loss from implementing fuel reduction treatments exceeded the expected carbon benefit associated with lowered burn probabilities and reduced fire severity on the treated landscape. Thus, fuel management activities resulted in an expected net loss of carbon immediately after treatment. However, the findings represent a point in time estimate (wildfire immediately after treatments), and a temporal analysis with a probabilistic framework used here is needed to model carbon dynamics over the life cycle of the fuel treatments. Of particular importance is the long-term balance between emissions from the decay of dead trees killed by fire and carbon sequestration by forest regeneration following wildfire. © Author(s) 2008.
Niwa C.G.,U.S. Department of Agriculture |
Overhulser D.L.,600 State Street
USDA Forest Service - Research Note PNW-RN | Year: 2015
A detailed procedure is described for monitoring western spruce budworm with pheromone-baited sticky traps and interpreting the results to predict defoliation the following year. Information provided includes timing of the survey, how to obtain traps and baits, how many traps are needed, trap assembly, field placement of traps, and how to evaluate the catches. © 2015, USDA Forest Service. All rights reserved.
Maguire D.A.,Oregon State University |
Mainwaring D.B.,Oregon State University |
Kanaskie A.,600 State Street
Canadian Journal of Forest Research | Year: 2011
Swiss needle cast, a foliar disease caused by the Ascomycete Phaeocryptopus gaeumannii (T. Rohde) Petr., continues to afflict Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in north coastal Oregon. Permanent plots were installed in 1998 to assess growth impacts and monitor disease severity. Gross periodic annual increment was measured for three 2- year growth periods and one 4-year growth period and ranged from 0.37 to 31.74 m 3·ha -1·year -1. Foliage retention, defined as the average number of annual needle age classes held by a tree, was also estimated as an index of disease severity. Assuming negligible losses in stands with maximum needle retention (approximately 3.9 years), growth losses in net periodic annual increment reached slightly over 50% in stands with the lowest needle retention (approximately 1 year). Mixed-effects regression models supported a consistent relationship between foliage retention and both gross and net periodic annual increment among the four growth periods. Periodic annual mortality ranged from 0 to 19.12 m 3·ha -1·year -1 but was not significantly influenced by Swiss needle cast as measured by average foliage retention. Minimum and maximum foliage retention has fluctuated annually from 1998 to 2008 on the permanent plots, but growth losses at a given level of foliage retention appear to have remained stable. Estimated growth losses are similar to those reported for comparable levels of defoliation by other agents.
Groom J.D.,Oregon State University |
Dent L.,600 State Street |
Madsen L.J.,Oregon State University
Water Resources Research | Year: 2011
Oregon's forested coastal watersheds support important cold-water fisheries of salmon and steelhead (Oncorhynchus spp.) as well as forestry-dependent local economies. Riparian timber harvest restrictions in Oregon and elsewhere are designed to protect stream habitat characteristics while enabling upland timber harvest. We present an assessment of riparian leave tree rule effectiveness at protecting streams from temperature increases in the Oregon Coast Range. We evaluated temperature responses to timber harvest at 33 privately owned and state forest sites with Oregon's water quality temperature antidegradation standard, the Protecting Cold Water (PCW) criterion. At each site we evaluated stream temperature patterns before and after harvest upstream, within, and downstream of harvest units. We developed a method for detecting stream temperature change between years that adhered as closely as possible to Oregon's water quality rule language. The procedure provided an exceedance history across sites that allowed us to quantify background and treatment (timber harvest) PCW exceedance rates. For streams adjacent to harvested areas on privately owned lands, preharvest to postharvest year comparisons exhibited a 40% probability of exceedance. Sites managed according to the more stringent state forest riparian standards did not exhibit exceedance rates that differed from preharvest, control, or downstream rates (5%). These results will inform policy discussion regarding the sufficiency of Oregon's forest practices regulation at protecting stream temperature. The analysis process itself may assist other states and countries in developing and evaluating their forest management and water quality antidegradation regulations. Copyright 2011 by the American Geophysical Union.
Peterson E.,Oregon State University |
Hansen E.,Oregon State University |
Kanaskie A.,600 State Street
Forest Ecology and Management | Year: 2014
The pathogen, Phytophthora ramorum, causal agent of sudden oak death (SOD) of oaks and tanoaks, continues to expand its range within Oregon despite an effort to eradicate it from native forests. With its early detection and prompt removal of infected hosts, the Oregon SOD eradication program has produced a landscape distribution of disease resulting predominantly from the long distance (100. m to 4. km) dispersal of inoculum between sites. Using a regionally restricted randomization test reflecting the south to north intensification of the SOD epidemic in Oregon, we assessed if the movement of P. ramorum between sites was spatially dependant upon roads and streams, topographic features associated with the landscape-scale movement of soil and water borne inoculum of related Phytophthora spp. Dissimilar to other forest Phytophthora spp. we found no association between SOD sites and the road network. We did, however, determine that SOD sites are occurring closer to streams than would be expected by chance, especially in regions with microclimates less conducive to establishment. Environmental conditions and/or dispersal mechanisms associated with streams may contribute to the distribution of SOD in Oregon tanoak forests. Monitoring and management should therefore concentrate on susceptible forests in close proximity to streams, especially in stands further inland from a coastal climate. © 2013 Elsevier B.V.
Peterson E.K.,Oregon State University |
Hansen E.M.,Oregon State University |
Kanaskie A.,600 State Street
Phytopathology | Year: 2015
An effort to eradicate Phytophthora ramorum, causal agent of sudden oak death, has been underway since its discovery in Oregon forests. Using an information-theoretical approach, we sought to model yearly variation in the size of newly infested areas and dispersal distance. Maximum dispersal distances were best modeled by spring and winter precipitation 2 years before detection, and infestation size the year prior. Infestation size was best modeled by infestation size and spring precipitation the year prior. In our interpretation, there is a 2-year delay between the introduction of inoculum and onset of mortality for a majority of sites. The year-long gap in between allows ample time for the production of inoculum contributing to the spread of P. ramorum. This is supported by epidemic development following changes in eradication protocols precipitated by an outbreak in 2011, attributable to a 2009 treatment delay and an uncharacteristically wet spring in 2010. Posteradication, we have observed an increase in the total area of new outbreaks and increased frequency in dispersal distances greater than 4 km. Although the eradication program has not eliminated P. ramorum from Oregon forests, it has likely moderated this epidemic, emphasizing the need for prompt treatment of future invasive forest pathogens. © 2015 The American Phytopathological Society.
Vaclavik T.,University of North Carolina at Charlotte |
Kanaskie A.,600 State Street |
Hansen E.M.,Oregon State University |
Ohmann J.L.,U.S. Department of Agriculture |
Meentemeyer R.K.,University of North Carolina at Charlotte
Forest Ecology and Management | Year: 2010
An isolated outbreak of the emerging forest disease sudden oak death was discovered in Oregon forests in 2001. Despite considerable control efforts, disease continues to spread from the introduction site due to slow and incomplete detection and eradication. Annual field surveys and laboratory tests between 2001 and 2009 confirmed a total of 802 infested locations. Here, we apply two invasive species distribution models (iSDMs) of sudden oak death establishment and spread risk to target early detection and control further disease spread in Oregon forests. The goal was to develop (1) a model of potential distribution that estimates the level and spatial variability of disease establishment and spread risk for western Oregon, and (2) a model of actual distribution that quantifies the relative likelihood of current invasion in the quarantine area. Our predictions were based on four groups of primary parameters that vary in space and time: climate conditions, topographical factors, abundance and susceptibility of host vegetation, and dispersal pressure. First, we used multi-criteria evaluation to identify large-scale areas at potential risk of infection. We mapped and ranked host abundance and susceptibility using geospatial vegetation data developed with gradient nearest neighbor imputation. The host vegetation and climate variables were parameterized in accordance to their epidemiological importance and the final appraisal scores were summarized by month to represent a cumulative spread risk index, standardized as five categories from very low to very high risk. Second, using the field data for calibration we applied the machine-learning method, maximum entropy, to predict the actual distribution of the sudden oak death epidemic. The dispersal pressure incorporated in the statistical model estimates the force of invasion at all susceptible locations, allowing us to quantify the relative likelihood of current disease incidence rather than its potential distribution. Our predictions show that 65km2 of forested land was invaded by 2009, but further disease spread threatens more than 2100km2 of forests across the western region of Oregon (very high and high risk). Areas at greatest risk of disease spread are concentrated in the southwest region of Oregon where the highest densities of susceptible host species exist. This research identifies high priority locations for early detection and invasion control and illustrates how iSDMs can be used to analyze the actual versus potential distribution of emerging infectious disease in a complex, heterogeneous ecosystem. © 2010 Elsevier B.V.
Kanaskie A.,600 State Street |
Hansen E.,Oregon State University |
Sutton W.,Oregon State University |
Reeser P.,Oregon State University |
Choquette C.,Oregon State University
New Zealand Journal of Forestry Science | Year: 2011
We conducted four experiments to evaluate the effectiveness of phosphonate application to tanoak (Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S.H.Oh) forests in south-western Oregon: (1) aerial application to forest stands; (2) trunk injection; (3) foliar spray of potted seedlings; and (4) foliar spray of stump sprouts. We compared aerial spray treatments: (1) no treatment (unsprayed); (2) low-dose (17.35 kg a.i. ha -1); and (3) high dose (34.5 kg a.i. ha -1), applied by helicopter in a carrier volume of 188 L ha -1 to 4-ha treatment plots. Treatments were applied in November 2007, in May 2008, and in December 2008 and May 2009 (double treatment). At the same time as the aerial application we injected phosphonate into the trunk of nearby mature tanoak trees at the standard label rates of 0.43 g a.i. cm-dbh-1. We used three different biological assays to measure uptake of phosphonate: (1) canopy twig dip in zoospore suspension; (2) in situ bole inoculation with Phytophthora gonapodyides (Petersen) Buisman; and (3) laboratory inoculation of log bolts with Phytophthora ramorum S. Werres, A.W.A.M. de Cock & W.A. Man in 't Veld and P. gonapodyides. We also simulated an aerial spray of potted seedlings, comparing an untreated control, a low dose (2.9 kg a.i. ha -1 applied in 935 L spray solution ha -1), and a high dose (17.35 kg a.i. ha -1applied in 187 L spray solution ha -1). Aerial spray with phosphonate consistently resulted in smaller bole lesions on trees challenge inoculated with Phytophthora gonapodyides in situ and in logs inoculated with P. ramorum. This effect persisted for 18 months post treatment. Results from detached canopy twig assays were variable and showed only small treatment effects. Trunk injection consistently reduced bole lesion size in trees and logs, but gave inconsistent results in the canopy twig assay, possibly due to the twig assay methodology. In the spring and autumn trunk injection treatment, canopy twig lesion length was reduced by 32 percent compared to untreated controls, indicating that trunk-injected phosphonate was mobilised to the outer twigs of the tree crown. Trunk injection with phosphonate resulted in a greater reduction in bole lesion area than aerial spray. Spray application of phosphonate to tanoak seedlings did not protect them from infection when exposed to artificial or natural inoculum of P. ramorum. Foliar application of phosphonate to stump sprouts reduced lesion length by 44% of control in a shoot-dip assay three months post-treatment. © 2011 New Zealand Forest Research Institute Limited, trading as Scion.