Treesearch

This article reports on an interdisciplinary evaluation of the pilot phase of a community-driven civic science project. The project investigates the distribution of heavy metals in air pollution using moss growing on street trees as a bio-indicator in two industrial-adjacent neighborhoods in Seattle, Washington (USA). One goal of the ongoing project is to meaningfully engage local urban youths (eighth to twelfth grade) in the scientific process as civic scientists, and teach them about environmental health, environmental justice, and urban forestry concepts in a place-based, urban-oriented...

Municipal water managers need to know if water will be reliably available from watersheds. Civil engineers need to calculate stream discharge to construct bridges to withstand 100-year floods. A hypothesis proposed in 1997 by Gordon Grant, a research hydrologist with the USDA Forest Service Pacific Northwest Research Station, underlies a method for getting this information from rivers without gauge networks or long-term flow data. Since then, laboratory experiments and field measurements have validated the hypothesis to the degree that it may now be considered a theory.Critical flow is a...

Scotch broom [Cytisus scoparius (L.) Link] is a large nonnative, leguminous shrub that threatens native plant communities by rapidly invading recently disturbed sites, competing vigorously for soil water and nutrients, and imparting soil legacy effects that inhibit native plants. In the Pacific Northwest, logging debris retention after forest harvesting prevents or slows C. scoparius invasions. A series of studies were conducted to determine potential mechanisms by which logging debris modifies the light environment to limit germination and growth of C. scoparius. In laboratory studies,...

Wildfires in dry forest ecosystems in western North America are producing fire effects that are more severe than historical estimates, raising concerns about the resilience of these landscapes to contemporary disturbances. Despite increasing fire activity, relatively little is known about the structure and composition of fire refugia - unburned or low‐severity burned patches where trees survived fire - or the degree to which their understory composition differs from fire‐generated early‐seral forests. Locations: Four recent large fires in dry mixed‐conifer forest in eastern Oregon, USA.

Wilderness areas offer value to society as a source of scientific information. We used fire perimeter records from the upper South Fork Flathead River watershed (Montana) to characterize the area burned one or more times during three periods: the pre-fire exclusion period (1889-1934), the fire exclusion period (1935-1980), and the fire management period (1981-2017). We also quantified the effects of a recent reburn on forest structure and fuels using a before-after-control-impact study design. Total area burned and area burned multiple times depended strongly on time period. The active...

Softwood logs comprise a large portion of forest product exports from the United States. Most of these exports have occurred between the Pacific Northwest region of the United States and several Asian countries. In this study, the extent and degree of market integration of softwood log exports from 1996 to 2018 are examined by co-integration analyses and permanent–transitory decomposition. Softwood log exports to Japan and South Korea appear to be in the same economic market and show a high degree of integration, while trade between the United States and China has evolved more independently...

This resource update is a brief look at some of the basic metrics that describe the status of and changes to forest resources in Arkansas. Estimates presented here are for the survey year 2019 with resource changes compared against the 2018 survey year. This information is based on field data collected using the Forest Inventory and Analysis (FIA) annualized sample design, and it is updated yearly. Arkansas has about 5,700 sample plots across the State; each year, 20 percent of these plots (one panel) are visited and measured by field crews, the data compiled, and new estimates produced....

With many degraded environments undergoing restoration efforts, there is a growing need for the optimization of direct seeding practices. Seeds planted on wildlands are often consumed by rodents, leading to reduced plant establishment. Coating seeds in rodent aversive products may prevent seed-predation. We tested 10 seed-coating formulations containing products expected to deter rodents, namely: ghost and cayenne pepper powders; essential oils from bergamot, neem, and pine; methyl-nonylketone, anthraquinone, activated carbon, beta-cyclodextrin, and a blank coating containing no rodent...

Monitoring elusive, relatively low-density, large predators, such as the grey wolf (Canis lupus), has often been accomplished by live-capture and radiocollaring. Increasingly, non-invasive methods are considered best practice whenever it is possible to use them. Recently, environmental DNA (eDNA) deposited in snow tracks was demonstrated as useful for identifying lynx (Lynx canadensis), fisher (Pekania pennanti), wolverine (Gulo gulo), sika deer (Cervus nippon), red fox (Vulpes vulpes), and the Japanese marten (Martes melampus) to species level using mitochondrial DNA (mtDNA) markers. We...

Restoration guidelines increasingly recognize the importance of genetic attributes in translocating native plant materials (NPMs). However, when species-specific genetic information is unavailable, seed transfer guidelines use climate-informed seed transfer zones (CSTZs) as an approximation. While CSTZs may improve how NPMs are developed and/or matched to restoration sites, they overlook genetic factors that can diminish restoration success and/or deteriorate natural patterns of genetic diversity and environmental factors thatmay introduce unexpected variation. Here, we analyze molecular...