Treesearch

Critical height sampling (CHS) estimates cubic volume per unit area by multiplying the sum of critical heights measured on trees tallied in a horizontal point sample (HPS) by the HPS basal area factor. One of the barriers to practical application of CHS is the fact that trees near the field location of the point-sampling sample point have critical heights that occur quite high on the stem, making them difficult to view from the sample point. To surmount this difficulty, use of the "antithetic variate" associated with the critical height together with importance sampling from the cylindrical...

Limited information is available on how soil and leaf populations of the sudden oak death pathogen, Phytophthora ramorum, may differ in their response to changing weather conditions, and their corresponding role in initiating the next disease cycle after unfavorable weather conditions. We sampled and cultured from 425 trees in six sites, three times at the end of a 3-year-long drought and twice during a wet year that followed. Soil was also sampled twice with similar frequency and design used for sampling leaves. Ten microsatellites were used for genetic analyses on cultures from successful...

Urban forest monitoring data are essential to assess the impacts of tree planting campaigns and management programs. Local practitioners have monitoring projects that have not been well documented in the urban forestry literature. To learn more about practitioner-driven monitoring efforts, the authors surveyed 32 local urban forestry organizations across the United States about the goals, challenges, methods, and uses of their monitoring programs, using an e-mailed questionnaire. Non-profit organizations, municipal agencies, state agencies, and utilities participated. One-half of the...

The second completed annual inventory of Kansas' forests reports 2.4 million acres of forest land, roughly 5 percent of the total land area in the State. Softwood forests account for 4.4 percent of the total timberland area. Oak/hickory forest types make up 55 percent of the total hardwood forest land area. Elm/ash/cottonwood accounts for more than 32 percent of the timberland area. Kansas' forests have continued to increase in volume. In 2010, net volume of growing stock on timberland was an estimated 1.45 billion cubic feet compared with 0.5 billion cubic feet in 1965. Live-tree biomass...

The UNECE region's economic recovery has been sluggish; national income in more than half of the region’s countries has yet to return to 2008 levels and unemployment remains high. Numerous risks remain that could endanger even moderate growth in 2014 and beyond as the eurozone crisis appears to be deepening. Further deterioration in the eurozone or an economic downturn in a major country might have significant implications not only for the European Union but also for the global economy. The European housing construction market is still stagnant due to the ongoing sovereign debt crisis, a...

Substantial knowledge has been generated in the U.S. about the resource base for forest and other residue-derived biomass for bioenergy including co-firing in power plants. However, a lack of understanding regarding power plant-level operations and manager perceptions of drivers of biomass co-firing remains. This study gathered information from U.S. power plant managers to identify drivers behind co-firing, determine key conditions influencing past and current use, and explore future prospects for biomass in co-firing. Most of the biomass used in co-firing was woody biomass procured within...

Past studies have established measures of co-firing potential at varying spatial scales to assess opportunities for renewable energy generation from woody biomass. This study estimated physical availability, within ecological and public policy constraints, and associated harvesting and delivery costs of woody biomass for co-firing in selected power plants of the Northern U.S. Procurement regimes were assessed for direct sources of woody biomass from timberland including logging residues (slash, by-products), small-diameter trees, and integrated harvest (logging residues and small-diameter...

Forests, covering about 30% of the earth’s land area, are a major component in the global ecosystem, influencing the carbon cycle, climate change, habitat protection, clean water supplies, and sustainable economies (FAO 2011). Globally, the vast cellulosic resource found in forests provides about half of all major industrial raw materials for renewable energy, chemical feedstock, and biocomposites (Winandy et al. 2008). Although forests and forest products have been used since the dawn of time, exciting new opportunities are emerging for sustainably meeting global energy needs and simultane...

Polyvinyl alcohol (PVA)–cellulose nanofibril (CNF)–multiwalled carbon nanotube (MWCNT) hybrid organic aerogels were prepared using an environmentally friendly freeze-drying process with renewable materials. The material properties of these “green” hybrid aerogels were characterized extensively using various techniques. It was found that adding a small amount of CNFs and MWCNTs increased the mechanical properties of the PVA aerogels drastically. The mechanical properties of the hybrid aerogels showed an exponential dependency on the relative aerogel densities. These low-density hybrid...

ASHRAE Standard 160, Criteria for Moisture-Control Design Analysis in Buildings, specifies moisture design criteria in buildings to prevent moisture damage such as fungal activity and corrosion. While there has been much research on mold and decay fungi in wood buildings, it is often overlooked that wet wood is corrosive to the metal screws or nails used to fasten it. Currently, corrosion design in Standard 160 is based upon relative humidity criteria that were developed for atmospheric corrosion. However, the corrosion of metals embedded with wood is controlled by wood chemistry and...