Treesearch

The wood-pellet trade between the U.S. (United States) and the EU (European Union) has increased substantially recently. This research analyzes the effects of EU biomass imports from the Southeast U.S. on Southeast U.S. timber prices, inventories and production and on EU imports of feedstock. The SRTS (sub-regional timber supply model) was used to simulate market responses to changes in woody biomass consumption in the U.S. and the EU between 2008 and 2038. Results indicate that the price of imported wood pellets in the EU is sensitive to future U.S. renewable energy policies, the developme...

Over a century of fire suppression activities have altered the structure and composition of mixed conifer forests throughout the western United States. In the absence of fire, fuels have accumulated in these forests causing concerns over the potential for catastrophic wildfires. Fuel reduction treatments are being used on federal and state lands to reduce the threat of wildfire by mechanically removing biomass. Although these treatments result in a reduction in fire hazard, their impact on wildlife is less clear. We use a multi-species occupancy modeling approach to build habitat-suitabilit...

Background: As a result of past practices, many of the dry coniferous forests of the western United States contain dense, even-aged stands with uncharacteristically high levels of litter and downed woody debris. These changes to the forest have received considerable attention as they elevate concerns regarding the outcome of wildland fire. However, attempts to reduce biomass through fuel reduction (i.e., thinning of trees) are often opposed by public interest groups whose objectives include maintaining habitat for species of concern such as the spotted owl, Strix occidentalis, the northern...

The invasion and spread of invasive plants is a major problem in forested ecosystems. Invasive plants can displace existing vegetation and in some cases take over the site. With the displacement of native vegetation come major ecosystem changes that may jeopardize ecological processes and functions as well as habitat for wildlife. The disturbance caused during timber harvesting processes creates conditions that encourage the establishment and spread of invasive plants. The machinery and traffic movement within a job site may introduce and spread seeds, roots, and plant parts from one job...

The Southern Forest Futures Project provides a science-based “futuring” analysis of the forests of the 13 States of the Southeastern United States. With findings organized in a set of scenarios and using a combination of computer models and science synthesis, the authors of the Southern Forest Futures Project examine a variety of possible futures that could shape forests and the many ecosystem services and values that forests provide. The science findings and modeling results could inform management and policy analysis of the South’s forests. In the chapters of this technical report, the...

In an effort to improve organizational outcomes, including safety, in wildland fire management, researchers and practitioners have turned to a domain of research on organizational performance known as High Reliability Organizing (HRO). The HRO paradigm emerged in the late 1980s in an effort to identify commonalities among organizations that function under hazardous conditions but experience fewer than their fair share of adverse events (see for instance: Klein and others 1995; Weick and others 1999; Weick and Sutcliffe 2001; Sutcliffe 2011).

Municipal fire departments responded to approximately 53,000 intentionally-set fires annually from 2003 to 2007, according to National Fire Protection Association figures. A disproportionate amount of these fires occur in spatio-temporal clusters, making them predictable and, perhaps, preventable. The objective of this research is to evaluate how the aggregation of data across space and target types (residential, non-residential, vehicle, outdoor and other) affects daily arson forecast accuracy for several target types of arson, and the ability to leverage information quantifying the...

Many functional properties of forests depend on the leaf area; however, measuring leaf area is not trivial in tall evergreen vegetation. As a result, leaf area is generally estimated indirectly by light absorption methods. These indirect methods are widely used, but have never been calibrated against direct measurements in tropical rain forests, either at point or landscape scales. Here, we compare direct harvest leaf area index (LAI) measurements taken across an old-growth tropical rain forest landscape with data from two indirect methods, digital hemispherical photography and the LI-COR...

Despite concern expressed two decades ago, there has been little recent discussion about continuing declines of migrant bird populations. Monitoring efforts have been focused almost exclusively on the breeding grounds. We describe the long-term decline of a winter-resident bird population in Guanica Commonwealth Forest, Puerto Rico, one of the last remaining tracts of high-quality tropical dry forests in the Caribbean. The winter bird community has exhibited dramatic declines, with constant-effort mist netting now capturing about one-third as many birds as it did 20 years ago. Population...

Forecasts of species distributions under future climates are inherently uncertain, but there have been few attempts to describe this uncertainty comprehensively in a probabilistic manner. We developed a Monte Carlo approach that accounts for uncertainty within generalized linear regression models (parameter uncertainty and residual error), uncertainty among competing models (model uncertainty), and uncertainty in future climate conditions (climate uncertainty) to produce site-specific frequency distributions of occurrence probabilities across a species' range. We illustrated the method by...