Treesearch

In the United States, fuel reduction treatments are a standard land management tool to restore the structure and composition of forests that have been degraded by past management. Although treatments can have multiple purposes, their principal objective is to create landscape conditions where wildland fire can be safely managed to help achieve long-term land management goals. One critique is that fuel treatment benefits are unlikely to transpire due to the low probability that treated areas will be burned by a subsequent fire within a treatment’s lifespan, but little quantitative informatio...

A goal of fire management in wilderness is to allow fire to play its natural ecological role without intervention. Unfortunately, most unplanned ignitions in wilderness are suppressed, in part because of the risk they might pose to values outside of the wilderness. We capitalize on recent advances in fire risk analysis to demonstrate a risk-based approach for revealing where unplanned ignitions in wilderness pose little risk to nonwilderness values and therefore where fire can be managed for its longer term ecological benefits. Using a large wilderness area as a case study, we conduct an...

The Wilderness Manager Survey (WMS) was developed in 2014 to support interagency strategic planning for the National Wilderness Preservation System (NWPS) and asked managers about their perceived threats to the NWPS, the need for science information to support decisionmaking, the need for education and training, and the most important problems for managers in the future. The WMS was administered during Feb. 24 to May 19, 2014, to wilderness managers in the four federal agencies who manage the lands of the NWPS, and 368 wilderness managers responded. The important external and internal...

Recent bark beetle outbreaks in North America and Europe have impacted forested landscapes and the provisioning of critical ecosystem services. The scale and intensity of many recent outbreaks are widely believed to be unprecedented. The effects of bark beetle outbreaks on ecosystems are often measured in terms of area affected, host tree mortality rates, and alterations to forest structure and composition. Impacts to human systems focus on changes in property valuation, infrastructure damage from falling trees, landscape aesthetics, and the quality and quantity of timber and water...

Land managers are responsible for developing effective strategies for conserving and restoring Great Basin ecosystems in the face of invasive species, conifer expansion, and altered fire regimes. A warming climate is magnifying the effects of these threats and adding urgency to implementation of management practices that will maintain or improve ecosystem functioning. This Factsheet Series was developed to provide land managers with brief summaries of the best available information on contemporary management issues to facilitate science delivery and foster effective management. Each...

Feral horse herds in the western United States are managed with the goal of maintaining "a thriving natural ecological balance" with their environment. Because rangeland ecology is complex and grazers such as horses can have different effects under different environmental conditions, more data are needed to better inform Appropriate Management Levels and other management decisions. We used long-term grazing exclosures and fenceline contrasts to evaluate the impacts of feral horses on plant communities at five sites across the western United States. These sites ranged from 229 to 413 mm...

Prescribed fire is applied widely as a management tool in North America to meet various objectives such as reducing fuel loads and fuel continuity, returning fire to an ecosystem, enhancing wildlife habitats, improving forage, preparing seedbeds, improving watershed conditions, enhancing nutrient cycling, controlling exotic weeds, and enhancing resilience from climate change. Regardless of the particular objective, fire affects ecosystem structure, composition, and function in many ways.

Since Parresol’s (Can. J. For. Res. 31:865-878, 2001) seminal article on the topic, it has become standard to develop nonlinear tree biomass equations to ensure compatibility among total and component predictions and to fit these equations using multistep generalized least-squares methods. In particular, many studies have specified equations for total tree biomass by aggregating the expectations of M component biomass models and have fit all M+1 equations jointly using seemingly unrelated regression. More recently, an alternative approach has been used wherein compatibility is ensured by...

This paper explores the relationship between forest cover and drinking water treatment costs using results from a 2014 survey by the American Water Works Association (AWWA) that targeted utilities in forested ecoregions in the United States. On the basis of the data collected, there is a negative relationship between forest cover and turbidity, i.e. as forest cover increased, turbidity decreased. However, the relationship between land use and total organic carbon (TOC) is not statistically significant. Within the bounds of the collected data, a conversion of 1% of a watershed from forested...

Background: Locating terrestrial sources and sinks of carbon (C) will be critical to developing strategies that contribute to the climate change mitigation goals of the Paris Agreement. Here we present spatially resolved estimates of net C change across United States (US) forest lands between 2006 and 2010 and attribute them to natural and anthropogenic processes. Results: Forests in the conterminous US sequestered −460 ± 48 Tg C year−1, while C losses from disturbance averaged 191 ± 10 Tg C year−1. Combining estimates of net C losses and gains results in net carbon change of −269 ± 49 Tg...