Treesearch

Asphalt was becoming an integral part of the urban American landscape by the end of the nineteenth century. Not only was it emerging as the preferred alternative for street paving, its promoters were endorsing it for other purposes as well. Although Baltimore was not in the vanguard when it came to adopting asphalt for road surfaces, it soon followed the trend. Like other cities, it too found other applications for this versatile petroleum product, including the paving of playgrounds and schoolyards. Despite low maintenance costs, widespread use of asphalt as a recreational surface started...

Immunolocalization can be used to precisely visualize the location of specific proteins, cell wall components, or any other molecules within cells or tissues for which specific antibodies are available. Here we describe an immunolocalization protocol for tissue sections of woody Populusstems. The protocol includes descriptions of the required sectioning, fixation, probing, detection, and imaging parameters, as well suggested controls useful in interpreting results.

Forests worldwide are impacted by a wide variety of disturbances that are happening more frequently with more intensity than in the past due to global climate change. Forest managers, therefore, need to identify new ways to quickly and accurately predict post-disturbance forest landscape composition. We suggest the use of Landsat satellite imagery and an image processing tool to map percent canopy cover (PCC) by species and sub-canopy species counts to be used in adaptive forest management strategies. We used zero-inflated models to successfully predict PCC and sub-canopy counts (number of...

The effect of landfill exposure on residual levels of cellulose, hemicellulose, and lignin was investigated on wood materials removed from differing depths in a 5-yr-old landfill cell in western Oregon. There was little evidence of change in the levels of these components with increasing landfill cell depth in softwood lumber, softwood plywood, or hardwood lumber. The results confirm studies at other landfills showing that wood degradation rates under anaerobic conditions in landfills are much slower than predicted and that models to predict these rates need to be modified.

The fungal pathogen Heterobasidion irregulare has caused substantial damage to pine species in much of the south-eastern United States, but the potential for damage from Heterobasidion root disease to forest tree species of the Great Lakes Region has not been thoroughly investigated. In each of three trials in two infested stands, fresh stem discs of six native conifer species were exposed to natural inoculum and examined for the asexual Spiniger stage of H. irregulare after incubation in the laboratory. In the first trial, the fungus was infrequently observed on discs, and differences...

In this study, we extended the spatial weight matrix defined by Getis and Aldstadt (2004) to a more general case to map the distribution of Rosa multiflora, an invasive shrub, across the Upper Midwest counties in a spatial lag model (SLM) context. Both the simulation study and the application to the invasion data of invasive Rosa multiflora collected in 2005-2006 proved that the modified spatial weight matrix outperforms its original case and the contiguity- and nearest distance- based spatial weight matrices in diagnostic statistics and resultant invasion maps. The geographical distributio...

Individuals and families collectively own more than 118 million ha of forestland in the USA. Using data from the USDA Forest Service's National Woodland Owners Survey (NWOS), we characterize ecosystem services being produced on family forests as well as the beneficiaries who enjoy them. Approximately half of family forest owners provide one or more provisioning services. With the exception of logs, the provisioning services provided by the majority of owners are enjoyed directly by owners or their close associates (i.e., family, friends, and neighbors). Similarly, while more than half of...

Thurber’s needlegrass (Achnatherum thurberianum [Piper] Barkworth) is a key restoration species in the Great Basin and surrounding areas, yet comprehensive studies of how climate relates to genetic variation and seed zones for restoration projects are lacking. Potentially adaptive phenotypic traits of 66 diverse populations of Thurber’s needlegrass were measured in common gardens at Central Ferry, Washington and Reno, Nevada in 2012 and 2013. Extensive genetic variation was observed among phenology, morphology, and production traits (P < 0.01), and canonical correlation was used to relate...

Wood-based products can be a sustainable and more environmentally friendly alternative to traditional construction materials because of their reduced contribution to air and water pollution. An integral component of these products is often an adhesive. Because wood is hygroscopic, moisture-induced swelling in the cell walls near the wood–adhesive bond lines can lead to durability and performance issues. Unfortunately, researchers working toward improving the moisture durability of forest products are hindered by an incomplete understanding of the nanoscale mechanisms that contribute to...

Wildfire is a key disturbance agent in forests worldwide, but recent large and costly fires have raised urgent questions about how different current fire regimes are from those of the past. Dendroecological reconstructions of historical fire frequency, severity, spatial variability, and extent, corroborated by other lines of evidence, are essential in addressing these questions. Existing methods can infer the severity of individual fires and stand-level fire regimes. However, novel research designs combining evidence of stand-level fire severity with fire extent are now being used to...