Treesearch

Erosion potential was estimated for road approaches during 4 phases of a timber harvesting scheduled for 23 stream crossings in the Virginia Piedmont. The objectives of this study were to: (1) examine four different types of stream crossing structures (steel bridges, pole bridges, standard culverts, and reenforced fords) in order to determine if the type of stream crossing affects erosion potential and (2) evaluate the potential erosion associated with the stream crossing approaches using the Water Erosion Prediction Project (WEPP) for forest roads and the forestry version of the Universal...

Throughout the country, foresters are continually looking at the effects of logging and forest roads on stream discharge and overall stream health. In the Pacific Northwest, a distributed hydrology-soil-vegetation model (DHSVM) has been used to predict the effects of logging on peak discharge in mountainous regions. DHSVM uses elevation, meteorological, vegetation, and soil data to model the hydrology of the catchment explicitly on a grid cell by grid cell scale. The model is unique in its ability to consider the impacts of road networks on catchment hydrology due to the addition of a road...

Bark beetle infested pines are an ephemeral habitat utilized by a diverse assemblage of insects. Although many bark beetle insect associates have little or no measurable impact on bark beetle brood production, some reduce brood production by either competing with brood for the limited phloem tissue or by feeding on brood. Several studies have observed synchrony between the colonization of hosts by bark beetles and the arrival of insect associates. Some insect associates mediate synchrony with bark beetle mass attacks with kairomonal responses to bark beetle aggregation pheromones. The...

Redbay ambrosia beetle, Xyleborus glabratus Eichoff, is an exotic species to North America vectoring a deadly vascular wilt disease of redbay [Persea borbonia (L.) Spreng], swampbay [P. palustris (Raf.) Sarg.], avocado (P. americana Mill.), and sassafras [Sassafras albidum (Nutt.) Nees]. Xyleborus glabratus is attracted to manuka oil lures, which are commercially available, and phoebe oil. Variable efficacy of manuka oil lures and insufficient availability of phoebe oil prompted us to investigate the reasons behind changes in manuka oil lure efficacy and to test cubeb oil, a readily...

In the basement of the Alexandria Forestry Center in Pineville works a scientist who many consider eccentric and few understand what he does, but most know that he works every work day and most weekends as a volunteer even though he retired from the Forest Service's Southern Research Station for nearly 25 years. The scientist, John Moser, has taken a path less traveled. Few know that Moser has published in sciences' most prestigious journals, has frequent international visitors, and has 20 species of insects named in his honor.

The roots of American ginseng have been harvested from the hardwood forests of eastern United States, along-side timber, since the mid-1700s. Very little is known about this non-timber commodity relative to timber, although significant volumes of ginseng root have been harvested from the same forests along with timber. The harvest of ginseng correlated positively and significantly with hardwood forest area, hardwood growing stock volume and timber removals. Also, it correlated with hardwood growing stock on public forest lands in the region. The annual wholesale value of American ginseng...

Active forest restoration in Hawaii’s Hakalau Forest National Wildlife Refuge has produced a network of Acacia koa tree corridors and islands in deforested grasslands. Passive restoration by root suckering has potential to expand tree cover and close gaps between planted stands. This study documents rates of encroachment into grassland, clonal stand structure, and tree architecture. Data were collected from random replicate strip transects that started inside 23-year-old koa plantations and ended either in open grassland or in adjacent planted stands. For the former, sucker densities...

Early in the 20th century, the forests of the South were decimated by aggressive harvesting, resulting in millions of acres of forest land in need of reforestation. Foresighted individuals committed efforts to restore this harvested land to a productive condition. The effort required dedication, cooperation, and leadership. The efforts of this small cadre of individuals resulted in successful restoration of the South’s forests and these new forests became the basis of the South’s economy.

Many forest inventory and monitoring programs are based on a sample of ground plots from which estimates of forest resources are derived. In addition to evaluating metrics such as number of trees or amount of cubic wood volume, it is often desirable to make comparisons between resource attributes. To properly conduct statistical tests for differences, it is imperative that analysts fully understand the underlying sampling design and estimation methods, particularly identifying situations where the estimates being compared do not arise from independent samples. Information from the Forest...

Drought periods are becoming more extreme worldwide and the ability of plants to contribute towards atmospheric flux is being compromised. Properly functioning stomata provide an exit for water that has been absorbed by the roots, funneled into various cell parts, and eventually released into the atmosphere via transpiration. By observing the effects that weather conditions such as climate change may have on stomatal density, distribution, and functioning, it may be possible to elucidate a portion of the mechanisms trees use to survive longer periods of water stress. This study analyzed...