Treesearch

Rapids are common in steep rivers, often forming where flow transitions from supercritical (Froude number, Fr>1) to subcritical (Fr<1) through a hydraulic jump. When upstream Fr is supercritical but close to 1, this transition may occur as an undular hydraulic jump, exhibiting a train of stationary waves downstream of the jump toe. Previous studies proposed a method to estimate discharge using only UHJ wave spacing and channel width combined with a wave dispersion equation for large water depths relative to the UHJ wavelength. This method is based on the hypotheses that, by their presence,...

The Northwest Climate Adaptation Science Center convened 92 researchers and practitioners from 37 different organizations across Washington, Oregon, and Idaho to create a community of practice around the ecological impacts of extreme heat in the region, using the record-breaking 2021 Pacific Northwest heat wave to explore potential impacts and adaptation responses. Through a kick-off meeting, workgroups, and final workshop, participants synthesized the state of knowledge around the biophysical, management and practice, and policy and human dimensions of this topic and identified research...

Concepts and models of fire refugia are increasingly important components of forest management and adaptation discussions in the context of wildland fire, forest and habitat conservation, and global change. Recent stand-replacing fires in mature and old-growth forests of the Pacific Northwest (PNW) region of the western United States have increased land manager and scientific interest in fire refugia that can provide important ecosystem services. Here we provide an overview of fire refugia concepts and products being actively developed and applied in forests of the PNW (Washington, Oregon,...

Climate models predict future increases in the frequency, magnitude, and duration of natural hazard events, including heat waves, droughts, and wildfires. People may be aware of these natural hazards but unfamiliar with new patterns expected under climate change. Ideally, people would take action to protect themselves from natural hazard events—even those with which they have limited prior experience. Doing so would likely reduce the public costs of later assisting individuals impacted by events when they occur. Although a large body of research has examined how people perceive and protect...

The U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station hosted a 2-day regional biomass workshop in May 2022, with the objective of reviewing recent developments, trends, and opportunities in biomass utilization. Day 1 focused on recent research, and Day 2 focused on biomass success stories from practitioners and business owners. About 120 attendees participated in this virtual event.Effective biomass utilization—from forest residues, wood products residues, and thinned or sustainably harvested stands—is one tool that managers have to help mitigate wildfire...

Passive Acoustic Monitoring (PAM) is an increasingly common method for monitoring birds and other sound-producing organisms at scale, but methods that digest these data streams into ecological insight remain underdeveloped. Specifically, using PAM and classification algorithms powered by artificial intelligence (AI) to uncover the phenology of vocal animals is an emerging use of these data but currently lacks standardized, repeatable methods with verified connections to biological phenomena. Here, we articulate specific hypotheses regarding the relationship between avian vocal activity and...

Headwater streams play critical roles in hydrologic and biogeochemical processes and functions, yet their spatial distribution and land cover context remain poorly understood at continental scales, and no dedicated geospatial dataset exists. Building from a high-resolution conterminous United States (CONUS) hydrography network dataset, we quantified the spatial extent, density, and upstream catchment characteristics of headwater stream segments across the CONUS. We identified approximately 8.4 million kilometers of headwater streams, finding that 77% of the total stream network consists of...

Aim: The biogeography and distribution of irruptive forest insect herbivores are driven by population level responses to host availability, temperature, and precipitation. Because the irruptive dynamics of tree‐killing insects such as spruce beetle are regulated by climate, it is imperative to quantify biogeographic drivers and limiters to develop informed predictions and forecasts of future outbreaks. Here, we: (1) identify subcontinental drivers of spruce beetle outbreak distributions, (2) compare drivers and limiters of outbreaks across regions, and (3) develop geospatial hindcasts and...

An increase in the occurrence of large, high severity wildfires in the western Pacific Northwest (PNW), USA, has created an urgent need for science to better inform forest management and policy decisions to maintain source water quality in the region. The western PNW faces similar challenges to other regions with shifting wildfire regimes and large population centers reliant on surface water from forested catchments. However, the uniquely wet and highly seasonal climate of the western PNW suggests that findings from other, more frequently burned regions may not be directly applicable. To...

Passive acoustic monitoring is increasingly used for broad-scale, noninvasive tracking of biodiversity across space and time, but processing the resulting audio data at scale remains a major challenge. To address this, we have iteratively developed PNW-Cnet, a convolutional neural network trained to detect wildlife vocalizations in unprocessed field recordings collected throughout a large, forested region of the western United States. Initially built to identify six owl species, PNW-Cnet has evolved through successive retrainings and dataset expansion. We trained PNW-Cnet v5 on 824,120...