Treesearch

The hemlock woolly adelgid (HWA), Adelges tsugae (Hemiptera: Adelgidae), is an invasive forest pest that threatens the existence of eastern hemlock (Tsuga canadensis (L.) Carr.) and Carolina hemlock (T. caroliniana Engelm.) in the eastern United States. It is a small, aphid like insect with piercing-sucking mouthparts that it uses to penetrate its host plant and feed off the xylem ray parenchyma cells (Young et al. 1995). The hemlock woolly adelgid is native to eastern Asia and northwestern North America where it feeds on, but does not kill, its host (Annand 1924, Havill et al. 2006). The...

Eucalyptus is the most widely planted hardwood crop in world-wide tropical and subtropical regions because of its high growth rate, broad adaptability, and multipurpose wood properties. Until the 1970s, the Eucalyptus plantations in Brazil were practically disease free. However, plantations have continued to expand into warmer and more humid areas that are more favorable to pathogen infection. Furthermore, the use of high-yielding genotypes with unknown disease resistance, the implementation of clonal forestry, and the introduction of new management techniques have favored the emergence of...

An increase in the demand for wood for energy, including liquid fuels, bioelectricity, and pellets, has the potential to affect traditional wood users, forestland uses, management intensities, and, ultimately, carbon sequestration. Recent studies have shown that increases in bioenergy harvests could lead to displacement of traditional wood-using industries in the short run and intensive management, land use change, and sawtimber market impacts in the long-run. We simulate timber markets, as well as land use response and carbon outcomes resulting from projections of both traditional and...

There are about 11.3 million private forest owners in the United States; of those, 10.4 million are family forest owners who control 62% of the nation's private timberland. South Carolina has about 262,000 family forest owners who control almost two-thirds of the state's private timberland (Butler, 2008). In the recent past, these ownerships were generally called nonindustrial private forests (NI PF). Due to development and growth of various corporate ownerships, the definition of NIPF became muddled. Today this unincorporated individual, family trust estate, and partnership-owned timberlan...

Research activities aimed at developing resistance to pests (insect, pathogens, mammals) in forest trees can be documented back over 5 decades. While a substantial body of research has been published on resistances in forest trees, not much of this work has made its way into applied tree improvement programs. There are several reasons for this, e.g.: (i) a new or interesting incursion is noticed, and studies are developed that work on materials not related to a breeding program; (ii) adequate infection or artificial inoculation techniques are too expensive and a large enough population...

Forest modeling applications that cover large geographic area can benefit from the use of widely-held knowledge about relationships between forest attributes and topographic variables. A noteworthy example involved the coupling of field survey data from the Forest Inventory Analysis (FIA) program of USDA Forest Service with digital elevation model (DEM) data in attempts to explain how topographic characteristics influence forest productivity, vegetation composition, fire behavior, and other phenomena. Because U.S. federal law prohibits the release of actual FIA plot coordinates, only...

With the advent of free Landsat data stretching back decades, there has been a surge of interest in utilizing remotely sensed data in multitemporal analysis for estimation of biophysical parameters. Such analysis is confounded by cloud cover and other image-specific problems, which result in missing data at various aperiodic times of the year. While there is a wealth of information contained in remotely sensed time series, the analysis of such time series is severely limited due to the missing data. This paper illustrates a technique which can greatly expand the possibilities of such...

The economic recession affected southern forests and related industries substantially, particularly those sectors most closely related to home construction. Between 2005 and 2009, for example, the three primary forestry sectors – wood manufacturing, paper manufacturing, and forestry and logging – lost more than 110,000 jobs in the southern United States. This article assesses the effects of the recession on the Southern U.S. by reviewing existing data related to economic and resource impacts, including employment, timber product output, production facilities, state economies, exports, and...

The different plant defenses existing within a given taxon have been commonly assumed to trade-off among each other because of both evolutionary and physiological reasons. The higher the efficiency of a single defensive trait, the lower selective pressure for other redundant defenses expected. On the other hand, production of multiple defenses might be constrained by the resources required for maintaining, at a time, increased growth and reproductive rates. However, different defensive traits do not need to always be redundant, and plants require the combination of multiple defenses to...

Individual papers are available at https://www.fs.usda.gov/psw/publications/documents/psw_gtr240/ The Fourth International Workshop on the Genetics of Host-Parasite Interactions in Forestry: Disease and Insect Resistance in Forest Trees provided a forum for research and management options and successes which have occurred over the last 30 years (the previous workshop was held in 1980 in Wageningen, The Netherlands). Eighty-eight submissions from oral and poster presentations at the 2011 workshop held in Eugene, Oregon provide a worldwide, comprehensive update on many aspects of research...