Treesearch

Massive tree mortality has occurred rapidly in frequent-fire-adapted forests of the Sierra Nevada, California. This mortality is a product of acute drought compounded by the long-established removal of a key ecosystem process: frequent, low- to moderate-intensity fire. The recent tree mortality has many implications for the future of these forests and the ecological goods and services they provide to society. Future wildfire hazard following this mortality can be generally characterized by decreased crown fire potential and increased surface fire intensity in the short to intermediate...

With the increase in natural gas production in the United States, land managers need solutions and best practices to mitigate potential negative impacts of forest and soil disturbance and meet landowner objectives and desired conditions. Mitigation often includes the use of native seed mixes for maintaining plant diversity, controlling nonnative invasive species, and erosion control. The area disturbed by installing a buried pipeline to transport natural gas from a gas well near Parsons, WV was used to test the performance of a native seed mix. The seed mix was applied at the recommended...

We provide updated spatial distribution and inventory data for on-road NH3 emissions for the continental United States (U.S.) On-road NH3 emissions were determined from on-road CO2 emissions data and empirical NH3:CO2 vehicle emissions ratios. Emissions of NH3 from on-road sources in urbanized regions are typically 0.1–1.3 t km− 2 yr− 1 while NH3 emissions in agricultural regions generally range from 0.4–5.5 t km− 2 yr− 1, with a few hotspots as high as 5.5–11.2 t km− 2 yr− 1. Counties with higher vehicle NH3 emissions than from agriculture include 40% of the U.S. population. The amount of...

Mountain runoff ultimately reflects the difference between precipitation (P) and evapotranspiration (ET), as modulated by biogeophysical mechanisms that intensify or alleviate drought impacts. These modulating mechanisms are seldom measured and not fully understood. The impact of the warm 2012–15 California drought on the heavily instrumented Kings River basin provides an extraordinary opportunity to enumerate four mechanisms that controlled the impact of drought on mountain hydrology. Two mechanisms intensified the impact: (i) evaporative processes have first access to local precipitation,...

The U.S. Forest Service Forest Inventory and Analysis (FIA) program collects sample plot data on all forest ownerships across the United States. FIA’s primary objective is to determine the extent, condition, volume, growth, and use of trees on the Nation’s forest land through a comprehensive inventory and analysis of the Nation’s forest resources. The FIA program strives for transparency by making the methods and results of the inventory and analysis available to the public. The standard for distributing FIA data is the FIADatabase (FIADB). FIADB data for individual states can be downloaded...

Managers and policy makers are continually working toward a desired future within a context of rapid and turbulent change. To be effective in this context, they must look ahead to anticipate emerging trends, issues, opportunities, and threats. Horizon scanning is a foresight method that can help managers and policy makers develop and maintain a broad and externally focused forward view to anticipate and align decisions with both emerging (near-term) and long-term futures. This article reports on the design and early stage development and implementation of a horizon scanning system establish...

As wildland fires have had increasing negative impacts on a range of human values, in many parts of the United States (U.S.) and around the world, collaborative risk reduction efforts among agencies, homeowners, and fire departments are needed to improve wildfire safety and mitigate risk. Using interview data from 46 senior officers from local fire departments around the U.S., we examine how leadership staff view their departments’ roles and responsibilities in wildfire risk reduction. Overall, our findings indicate that local fire personnel are often performing a variety of mitigation...

A balanced diet and regular exercise are fundamental for good health, and a daily dose of nature may be equally important. Nearly 40 years of research has demonstrated that “metro nature”—nature found in urban environments, such as parks or tree-lined streets—provides positive and measurable health benefits and improves people’s quality of life. A research team led by Kathleen Wolf, a research social scientist with the U.S. Forest Service Pacific Northwest Research Station, found that the health benefits associated with metro nature have a calculable economic impact. The team surveyed...

Young stands are commonly assumed to require centuries to develop into late-successional forest habitat. This viewpoint reflects the fact that young stands often lack many of the structural features that define late-successional habitat, and that these features derive from complex stand dynamics that are difficult to mimic with forest management. Variable density thinning (VDT) is a silvicultural strategy designed to accelerate development of late-successional habitat by applying a variety of harvest intensities within a stand. Previous reports indicate that VDT has had initial success...

Paleoclimate reconstructions are increasingly used to characterize annual climate variability prior to the instrumental record, to improve estimates of climate extremes, and to provide a baseline for climate change projections. To date, paleoclimate records have seen limited engineering use to estimate hydrologic risks because water systems models and managers usually require streamflow input at the monthly scale. This study explores the hypothesis that monthly streamflows can be adequately modeled by statistically decomposing annual flow reconstructions. To test this hypothesis, a...