Treesearch

The Collaborative Forest Landscape Restoration Program (CFLRP), established in 2009, encourages collaborative landscape scale ecosystem restoration efforts on United States Forest Service (USFS) lands. Although the USFS employees have experience engaging in collaborative planning, CFLRP requires collaboration in implementation, a domain where little prior experience can be drawn on for guidance. The purpose of this research is to identify the ways in which CFLRPs collaborative participants and agency personnel conceptualize how stakeholders can contribute to implementation on landscape...

Without large scale disturbances to alter forest structure and open the canopy, historically oak-dominated forests of the central and Appalachian hardwood regions of eastern North America are shifting to dominance by shade-tolerant, ‘mesophytic’ species. In response, prescribed fire is applied with increasing frequency and spatial extent to decrease non-oak species and promote dominance of oak species. However, relatively few studies have examined impacts of repeated fire to forest structure and tree vigor across multiple years and varied terrain. In this study, we examined tree vigor,...

Aim: Deterministic niche theory predicts that increasing environmental heterogeneity increases species richness. In contrast, a recent stochastic model suggests that heterogeneity has a unimodal effect on species richness since high levels of heterogeneity reduce the effective area available per species, thereby increasing the likelihood of stochastic extinction (the ‘area-heterogeneity trade-off’). We tested these contrasting predictions using data on bird distributions in North America.Location: North America.Methods: The effect of heterogeneity on species richness was tested using...

The South’s production of pulpwood increased from 62.7 million cords in 2011 to 63.7 million cords in 2012. Roundwood production decreased by 770,000 cords to 49.3 million cords and accounted for 78 percent of the South’s total pulpwood production. The use of wood residue dropped 15 percent to 14.4 million cords in 2012. Georgia and Alabama led the South in total production, with 10.5 and 10.0 million cords, respectively. In 2012, 82 mills were operating and drawing wood from the 13 Southern States. Pulping capacity of Southern mills increased from 122,218 tons per day in 2011 to 123,427...

Canopy fire hazard evaluation is essential for prioritizing fuel treatments and for assessing potential risk to firefighters during suppression activities. Fire hazard is usually expressed as predicted potential fire behavior, which is sensitive to the methodology used to quantitatively describe fuel profiles: methodologies that assume that fuel is distributed uniformly throughout crowns have been shown to predict less severe fire behavior than those that assume more realistic nonuniform fuel distributions. We used crown fuel data from seven interior western United States conifer species...

Expansion of juniper on U.S. rangelands is a significant environmental concern. Prescribed fire is often recommended to control juniper. To that end, a prescribed burn was conducted in a Great Basin juniper woodland. Conditions were suboptimal; fire did not encroach into mid- or late-seral stages and was patchy in the early-seral stage. This study evaluated the effects of the burn on biological soil crusts of early-seral juniper. Fire reduced moss cover under sagebrush and in shrub interspaces. Mosses were rare under juniper; their cover was unaffected there. Lichens were uncommon under...

Potential effects of hypothesized anthropogenic climate change are raising concerns about the sustainability of development in terms of both people and the rest of the environment. Land use change at the global scale presents many challenges for the research community. Past land use has a definite effect on future ecosystems, but it is challenging to predict future outcomes for biodiversity and productivity of ecosystems. The mechanisms that create complex patterns of forests at different scales (e.g., microscopic, stand-level) will require further systematic analysis.

Divergent natural selection drives a considerable amount of the phenotypic and genetic variation observed in natural populations. For example, variation in the predator community can generate conflicting selection on behavioral, life-history, morphological, and performance traits. Differences in predator regime can subsequently increase phenotypic and genetic variations in the population and result in the evolution of reproductive barriers (ecological speciation) or phenotypic plasticity. We evaluated morphology and swimming performance in field collected Bronze Frog larvae (Lithobates...

Steelhead are the sea-going form of Oncorhynchus mykiss. Rainbow trout,also O. mykiss, remain in freshwater. Each form, or life-history, can produce offspring of the other, but the mechanism for this and potential effects that climate change may have on the species are poorly understood. Forest Service scientist Gordie Reeves, along with colleagues from other federal agencies and Oregon State University, conducted a series of studies to better document the biological processes that affect the life-history expression of O. mykiss. They found that standard metabolic rate and lipid levels...

Molecular dynamics simulation is commonly used to study the properties of nanocellulose-based materials at the atomic scale. It is well known that the accuracy of these simulations strongly depends on the force field that describes energetic interactions. However, since there is no force field developed specifically for cellulose, researchers utilize models parameterized for other materials. In this work, we evaluate three reactive force field (ReaxFF) parameter sets and compare them with two commonly-used non-reactive force fields (COMPASS and GLYCAM) in terms of their ability to predict...