Treesearch

Variable retention harvesting (VRH) systems have gained wide use in many different forest types across the globe, but largely have been implemented in forests characterized by severe, infrequent disturbance regimes. There has been less attention given to developing VRH approaches in forests that are characterized as having a mixed-severity disturbance regime that often results in only partial mortality of canopy trees in spatially heterogeneous patterns. One example of such a forest type is red pine (Pinus resinosa Ait.)-dominated ecosystem of the western Great Lakes region of North...

Invasive Asian earthworms are increasingly common in the eastern USA where they are a major cause of terrestrial ecosystem disturbance. Among these, Amynthas agrestis (Crazy Worm, Alabama Jumper, and other common names) has been shown to alter above and belowground food webs. Life-history traits of these earthworms are largely unknown, particularly in their invaded range. Here, we sought to answer questions about temperature effects on hatching success for cocoons of this species, using specimens collected from the southern Appalachian Mountains. We conducted 2 experiments investigating...

Forests have a prominent role in carbon sequestration and storage. Climate change and anthropogenic forcing have altered the dominant characteristics of some forested ecosystems through changes to their disturbance regimes, particularly fire. Ecosystems that historically burned frequently, like pinelands in the southeastern United States, risk changes in their structure and function when the fire regime they require is altered. Although the carbon storage potential in an unburned southeastern U.S. forest would be larger, this scenario is unrealistic due to the likelihood of wildfire....

Future alongshore benthic species shoreline lengths undergoing both sea level rise and relative sea level lowering (postglacial isostatic rebound) where SE Alaska Natives regularly conduct traditional and cultural harvests were approximated. From 30-km radii of six community centers, shorelines were examined by merging relevant portions of the NOAA ShoreZone database (utilizing alongshore bioband length segments as accounting units) with nearshore bathymetry and measures of mean global sea-level rise along with local GPS information of isostatic rebound rate. For this analysis, adjustments...

Background: Increasingly frequent and severe drought in the western United States has contributed to morefrequent and severe wildfires, longer fire seasons, and more frequent bark beetle outbreaks that kill largenumbers of trees. Climate change is expected to perpetuate these trends, especially in montane ecosystems,calling for improved strategies for managing Western forests and conserving the wildlife that they support.Woodboring beetles (e.g., Buprestidae and Cerambycidae) colonize dead and weakened trees and speedsuccession of habitats altered by fire or bark beetles, while serving as...

Extreme wildfires in coniferous forests produce large areas of dead trees (snags) that are expected to provide much needed habitat for the Black-backed Woodpecker, a postfire associate. In an attempt to better understand extreme fire effects (including increasing fire size and decreasing diversity of fire effects), we monitored Black-backed Woodpeckers during the 2014 and 2015 breeding seasons following two wildfires (the 2013 Rim and 2014 King fire) that burned in the Sierra Nevada, USA under extreme fire conditions. Despite an extensive sampling effort including 1025 broadcast surveys...

Much of California, U.S. experienced a severe drought in 2012–2015 inciting a large tree mortality event in the central and southern Sierra Nevada. We assessed causal agents and rates of tree mortality, and short-term impacts to forest structure and composition based on a network of 11.3-m fixed-radius plots installed within three elevation bands on the Eldorado, Stanislaus, Sierra and Sequoia National Forests (914–1219, 1219–1524 and 1524–1829 m on the Eldorado, Stanislaus, Sierra; 1219–1524, 1524–1829, and 1829–2134 m on the Sequoia), where tree mortality was most severe. About 48.9% of...

This field guide provides 74 photographs that depict observed fuel loads within the Southern Appalachian Mountains. The guide contains instructions on how to select a reference photograph and utilize the fuel loading information to aid in prescribed fire planning.

The theory of the natural hedge states that agricultural yields and prices are inversely related. Actuarial rules for U.S. crop revenue insurance assume that dependence between yield and price is constant across all counties within a state and that dependence can be adequately described by the Gaussian copula.We use nonlinear measures of association and a selection of bivariate copulas to empirically characterize spatially-varying dependence between prices and yields and examine premium rate sensitivity for all corn producing counties in the United States. A simulation analysis across...

Marbled Murrelets are threatened seabirds that nest predominantly in old-growth forests in the southern part of their western North America range. Little is known about causes of nest failure, timing of parental visits, and nest reuse because it is difficult to locate and monitor nests of this cryptic species. We used radio telemetry to locate murrelet nests from 2004 to 2008 in northwestern Washington and southeastern British Columbia. We monitored four nests with video cameras to document causes of nest failure, and we visited 15 nests after the nesting season to infer nest fate. We also...