Treesearch

Forest ecosystems store large amounts of carbon and can be important sources, or sinks, of the atmospheric carbon dioxide that is contributing to global warming. Understanding the carbon storage potential of different forests and their response to management and disturbance events are fundamental to developing policies and scenarios to partially offset greenhouse gas emissions. Projections of live tree carbon accumulation are handled differently in different models, with inconsistent results. We developed growth-and-yield style models to predict stand-level live tree carbon density as a...

Urban smoke exposure events from large wildfires have become increasingly common in California and throughout the western United States. The ability to study the impacts of high smoke aerosol exposures from these events on the public is limited by the availability of high-quality, spatially resolved estimates of aerosol concentrations. Methods for assigning aerosol exposure often employ multiple data sets that are time-consuming to create and difficult to reproduce. As these events have gone from occasional to nearly annual in frequency, the need for rapid smoke exposure assessments has...

Data from tree cores and disks were used to develop biomass and carbon mass taper models for five major Sierra Nevada conifer species. These taper models were used to predict masses of tree boles, tree bole portions, branch, and foliage using carbon fraction data for oven-dried and living tissues. Taper models developed using core data were well modeled to disk data with R2 values ranging from 0.98 to 0.99 by inclusion of a calibration parameter. The fit of the final models suggests our approach can be used to include large diameter trees that cannot be cut down in biomass data collection...

Both elevated temperature and reduced precipitation have been related to growth declines in Douglas-fir (Pseudotsuga menziesii) in the northwest U.S. However, the impact of high vapor pressure deficit (VPD) on Douglas-fir growth and physiological stress is not fully understood. We investigated how inter- and intra-annual rainfall and VPD correlated to the radial growth and carbon isotope signature (δ13C) of latewood for ~ 50-year-old Douglas-fir trees in the western Cascade Mountains in Oregon. Latewood δ13C reflects variation in stomatal restriction of photosynthetic gas exchange and,...

While there has been extensive research on resident sentiment towards tourism, few have explored the uniqueness of gateway communities and their relationship to the Protected Areas (PA) surrounding them. This study explores how resident trust of PA managers and support for PAs surrounding their community can spillover to explain additional variance in resident support or opposition to tourism. To test this, traditional antecedents to resident support for tourism, like psychological, social, and political empowerment and the economic benefits from tourism, were modeled independently and in...

This report traces the flow of timber harvested in Alaska during calendar year 2019, describes the composition and operations of the state’s primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as trends in timber harvest, production, log exports, sales of primary wood products, employment, and emerging issues for Alaska’s forest industry.

Coastal giant salamanders (Dicamptodon tenebrosus) have lived in forests of the Pacific Northwest for tens of thousands of years. Their survivability is a testament to their ability to withstand and adapt to long-term changes. But can they withstand a succession of more rapid changes resulting from human intrusion and compounded by climate change? Dede Olson, a scientist with the USDA Forest Service Pacific Northwest Research Station, has studied the intersection of salamanders and forest management practices for more than 30 years. She recently conducted studies of how the management of...

Fire suppression has increased competitive tree encroachment of Oregon white oak (Quercus garryanna Douglas ex Hook) ecosystems, threatening maintenance of this important species. Restoration of oak ecosystems is ideal to address this threat but not always possible, giving rise to a need for novel treatments that will allow oak to persist on an altered landscape. We tested the effect of three release treatments centered around individual Oregon oak trees within four forested sites that had developed following encroachment and overtopping by Douglas-fir (Pseudotsuga menziesii[Mirb.] Franco...

Inland wetlands are critical carbon reservoirs storing 30% of global soil organic carbon (SOC) within 6% of the land surface. However, forested regions contain SOC-rich wetlands that are not included in current maps, which we refer to as ‘cryptic carbon’. Here, to demonstrate the magnitude and distribution of cryptic carbon, we measure and map SOC stocks as a function of a continuous, upland-to-wetland gradient across the Hoh River Watershed (HRW) in the Pacific Northwest of the U.S., comprising 68,145 ha. Total catchment SOC at 30 cm depth (5.0 TgC) is between estimates from global SOC...

Population monitoring is an essential component of biodiversity conservation and management, but low detection probabilities for rare and/or cryptic species makes estimating abundance and occupancy challenging. Passive acoustic monitoring combined with machine learning algorithms represents a potential path forward to effectively and efficiently monitor the occurrence of rare vocalizing species across entire forest landscapes. Our objectives were to develop and implement a convolutional neural network (PNW-Cnet) to identify vocalizations of a rare and threatened forest nesting bird species...