Treesearch

The construction of low-rise nonresidential buildings is an important market for lumber, engineered wood products, and structural and nonstructural wood panels in the United States. This report examines low-rise nonresidential buildings of six or fewer stories. Those with more than six stories are normally severely restricted by building codes from being wood framed.

Jeffrey pine, Pinus jeffreyi Greville and Balfour, is a dominant yellow pine and important overstory component of forests growing on diverse sites from southwestern Oregon to Baja California to western Nevada. The Jeffrey pine beetle, Dedroctonus jeffreyi Hopkins (Coleoptera: Curculionidae: Scolytinae), is monophagous on Jeffrey pine and its primary insect pest. Despite the importance of P. jeffreyi, difficult terrain, environmental concerns, and lack of roads can constrain pest management activities. Semiochemicals are often easier to apply and more environmentally acceptable than other...

We studied patterns of conifer regeneration over 12 years as part of a regional-scale experiment in variable-retention harvest in the Pacific Northwest, the DEMO Study. We compared survival and height growth of planted conifers and density and seral composition of natural regeneration among treatments with differing retention levels (15% versus 40%) and patterns (dispersed versus aggregated) replicated across a range of latitudes and forest zones. We also assessed plot-scale relationships of natural regeneration with overstory density and basal area, competing vegetation, and slash...

Urbanization processes challenge ecosystem health in many metropolitan areas. New policy and program approaches are needed to restore and sustain natural systems as public agencies and organizations face greater demands and declining budgets. Environmental stewardship is an often overlooked intervention strategy, and the full potential of civic engagement by citizens on behalf of ecosystem health is little understood. Using a coupled systems approach, integrated analysis of social and ecological footprints can lead to greater theoretical understanding and more effective programs at the...

The rapid worldwide emergence of the amphibian pathogen Batrachochytrium dendrobatidis (Bd) is having a profound negative impact on biodiversity. However, global research efforts are fragmented and an overarching synthesis of global infection data is lacking. Here, we provide results from a community tool for the compilation of worldwide Bd presence and report on the analyses of data collated over a four-year period. Using this online database, we analysed: 1) spatial and taxonomic patterns of infection, including amphibian families that appear over- and under-infected; 2) relationships...

Managing forests for resilience is crucial in the face of uncertain future environmental conditions. Because harvest gap size alters the species diversity and vertical and horizontal structural heterogeneity, there may be an optimum range of gap sizes for conferring resilience to environmental uncertainty. We examined the impacts of different harvest gap sizes on structure and composition in northern hardwood forests of the upper Great Lakes region, USA using a robustly-designed experiment consisting of six harvest gap sizes replicated 12 times with over a decade of repeated measurements....

The longest active study of the effects of thinning and pruning on growth of loblolly pine (Pinus taeda L.) was established by Dr. James D. Burton in 1970 in a typical 12-year-old loblolly pine (plantation was 11 years old) stand planted by then the Georgia-Pacific Corporation in the southeastern corner of Arkansas. Basal area has been maintained at 30, 50, 70, and 90 square feet per acre by periodic thinnings. Within each level of basal area plots were pruned in two stages at 12 and 15 years, finally clearing the bole to heights of 33, 26, and 22 feet and reducing crown lengths to 25, 40,...

Body size and development time are two critical phenotypic traits that can be highly adaptive in insects. Recent population genetic analyses and crossing experiments with the mountain pine beetle (Dendroctonus ponderosae Hopkins) have described substantial levels of neutral molecular genetic differentiation, genetic differences in phenotypic traits, and reproductive isolation. To determine whether genetic differences in adaptive phenotypic traits exist that correspond to reproductive boundaries, we conducted a common garden experiment with seven D. ponderosae populations previously used to...

A gap exists in the understanding of the effectiveness of forest road best management practices (BMP) in controlling sediment movement and minimizing risks of sediment delivery to forest streams. The objective of this paper is to report the findings of investigations to assess sediment travel distances downslope of forest roads in the Appalachian region, relate sediment travel distances to BMP recommendations, and describe the deposition patterns within buffer zones. A total of 164 randomly selected sediment deposition zones were measured downslope of the road lead-off ditch structures for...

US forestlands are increasingly subject to disturbances including wildfire, insects and disease, and urban and exurban development. Devising strategies for addressing these “forest threats” depends on anticipating where individual disturbances are most likely and where they might occur in combination. However, many spatial data sets describing forest threats are produced at fine scales but are intended only for coarse-scale planning and policy purposes. We demonstrate one way to combine and display forest threat data at their appropriate spatial scales, using spatial data characterizing...