Treesearch

Scientists and natural resource managers use bioindicators for overcoming the limitations of instrument-based monitoring networks. Low sampling costs make lichen bioindicators an invaluable tool for detecting finer scaled patterns in air quality than can be detected using instruments. Between 1989 and 2012, three Forest Service programs collected more than 8,300 surveys of epiphytic lichen communities, creating one of the largest systematically sampled lichen datasets in the world. More than 90 studies use these data as a baseline for tracking air quality, climate, and other changes on...

Questions: What are the rate, reversibility, and degree of symmetry in plant species compositional change in response to the addition and removal of cattle grazing in the shortgrass steppe? Specifically, how does the imposition and removal of grazing affect the abundance of perennial C4 shortgrasses and C3 midgrasses that are of primary importance for livestock production in the region?Location: Shortgrass steppe, northeastern Colorado, USA, in the North American Great Plains.Methods: We evaluate rates and magnitude of basal cover change in newly ungrazed and newly grazed sites (established...

This report presents considerations of potential hazards and mitigation measures associated with conducting field research in the context of a pathogenic epidemic or pandemic situation. We use an example of a specific risk assessment developed for advising decisions on initiating or continuing field activities (in this case, markresight and passive acoustic monitoring) associated with ongoing research of northern spotted owls (Strix occidentalis caurina) in the Pacific Northwest region of the United States under conditions imposed by the COVID-19 (severe acute respiratory syndrome coronavir...

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,...

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...

We demonstrate a generalizable approach for assessing climate change effects on tribally important ecosystem goods and services. Indigenous peoples may be highly vulnerable to the impacts of climate change because they rely on ecosystem goods and services, such as traditional foods, hunting, timber production, nontimber forest resources, and cultural resources. However, there are few assessments that have examined the potential impact of climate change on these goods and services and even less that examine ecological, socio-economic, and cultural resources in the Pacific Northwest, USA....

U.S. federal government agencies play an important role in mitigating some risks posed to communities by natural hazard events, especially communities with high proportions of low-income or minority residents. Ongoing efforts of the U.S. Forest Service (USFS) to reduce the buildup of forest fuels on national forests, particularly in dry mixed-conifer forests of the U.S. West, are an example. Federal land management agencies must comply with the Executive Order on Environmental Justice (EJ Order, 59 Fed. Reg 7629, 1994), but there is scant documentation of whether these agencies have...

In Southern California, the Santa Ana winds are famous for their role in spreading large wildfires during the fall/winter season. Combined with Southern California's complex topography, Santa Anas create challenges for modeling wind-fire relationships in this region. Here, we assess heterogeneity of winds during Santa Ana and non-Santa Ana days, on days with and without large-fire ignitions, across a modern high-density observational network of 30 meteorological stations. Wind speeds on Santa Ana days with a large fire ignition (mean windspeed = 5.19 m/s) are significantly higher than on...