Treesearch

Wood protection systems are needed for engineered composite products that are susceptible to moisture and biodeterioration. Protection systems using nano-materials are being developed to enhance the durability of wood-based composites through improved resistance to biodeterioration, reduced environmental impact from chemical leaching, and improved resistance to ultraviolet (UV) degradation. Three approaches will be presented: (1) direct application of nanometals to wood-based products, (2) slow release of biocides embedded in nano-polymer matrices, and (3) controlled delivery of biocides...

Depending on the severity, fire damage can compromise the structural integrity of wood structures such as buildings or residences. Fire damage of wood structures can incorporate several models that address (1) the type, cause, and spread of the fire, (2) the thermal gradients and fire-resistance ratings, and (3) the residual load capacity (Figure 6.1). If there is a danger of local collapse, immediate concerns about the stability of free-standing residual parts of a fire-damaged building will need to be addressed very quickly [1]. Assuming that the structural fire is contained, then under...

The Sirex noctilio (woodwasp - Amylostereum areolatum (fungus) complex has caused substantial losses to pine industries in its introduced range. The nematode Deladenus siricidicola that parasitizes S. noctilio and feeds on A. areolatum is widely used as a biological control agent for S. noctilio, but not with consistent success. This variable success could be due to factors that influence the feeding and reproductive ability of the nematode on A. Areolatum. We test two main hypotehese that emerge from this prediction. First, we compared the survival of D. siticidicola on the South African...

Accounting for both climate change and natural disturbances—which typically result in greenhouse gas emissions—is necessary to begin managing forest carbon sequestration. Gaining a complete understanding of forest carbon dynamics is, however, challenging in systems characterized by historic over-utilization, diverse soils and tree species, and frequent disturbance. In order to elucidate the cascading effects of potential climate change on such systems, we projected forest carbon dynamics, including soil carbon changes, and shifts in tree species composition as a consequence of...

Distribution of fishes, both occupancy and abundance, is often correlated with landscape-scale characteristics (e.g., geology, climate, and human disturbance). Understanding these relationships is essential for effective conservation of depressed populations. We used landscape characteristics to explain the distribution of coho salmon (Oncorhynchus kisutch) in the Oregon Plan data set, one of the first long-term, probabilistic salmon monitoring data sets covering the full range of potential habitat. First we compared data structure and model performance between the Oregon Plan data set and...

A distributed air pollutant dry deposition modeling systemwas developed with a geographic information system (GIS) to enhance the functionality of i-Tree Eco (i-Tree, 2011). With the developed system, temperature, leaf area index (LAI) and air pollutant concentration in a spatially distributed form can be estimated, and based on these and other input variables, dry deposition of carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter less than 10 microns (PM10) to trees can be spatially quantified. Employing nationally available road network, traffic...

Hawaii and the U.S.-affiliated Pacific islands, including Guam, American Samoa, Commonwealth of Northern Mariana Islands, Federated States of Micronesia, Republic of Palau, and the Marshall Islands (fig. A1-3), contain a high diversity of flora, fauna, ecosystems, geographies, and cultures, with climates ranging from lowland tropical to alpine desert. Forest ecosystems range from equatorial mangrove swamps to subalpine dry forests on high islands, with most other forest life zones between. As a result, associated climate change effects and potential management strategies vary across the...

American chestnut was eliminated as a canopy tree from the Appalachian region of North America with the introduction of chestnut blight in the early 1900s. Breeding programs initiated in the 1980s have produced seedling lines that display the pure American morphology with potential resistance to chestnut blight. More work is required to assess their field performance in field sites representative of their native range. This study used American (Castanea dentata) and backcrossed hybrid chestnuts (C. dentata × C. mollissima) on an abandoned coal mine in southeastern Ohio. Half of the seeds...

Castanea sativa Mill. is an ecologically and economically important species in Europe, not only as a forest tree, but also as a fruit tree. It is dramatically threatened by ink disease caused by Phytophthora spp., introduced during the nineteenth century. To limit its impact, C. mollissima and C. crenata, which proved to be tolerant species, were imported from China and Japan to Europe at the beginning of the twentieth century, together with the agent of chestnut blight (Cryphonectria parasitica) which is now spreading throughout Europe. A clonal selection has resulted in the use of a few...

In the 20th century, elms across Europe and North America were devastated by two pandemics of Dutch elm disease (DED), caused by the introduction of two fungal pathogens: Ophiostoma ulmi, followed by O. novo-ulmi. At the end of 1920s, research into a resistance to DED began in Europe and then in the United States. No worthwhile resistance was ever found within the native European or American elms. The Dutch team resorted to hybridizing European elms, from which the first cultivars exhibiting a resistance were obtained during the 1930s, but these clones did not have sufficient resistance to...