نتایج جستجو برای: pine trees
تعداد نتایج: 104582 فیلتر نتایج به سال:
A time and motion study was conducted to determine the produciivity and cost of an in-woods chipping operation when processing whole mall-diameter trees for biomoss. The study removed biomass from two overstocked stands and compared the cost of this treatment to existing alternatives. The treatment stands consisted of a 30-year-old longleaf pine stand and o 37-year-old loblolly pine stand. In t...
Replicated circular openings ranging in size from 0.1 to 1 ha were cleared in 1996 at Blodgett Forest Research Station, California, and planted with seedlings of six native species. After 5 years of postharvest growth, heights were measured and analyzed according to species, opening size, and location within opening. The sequence of mean height from tallest to shortest, according to species, wa...
The mountain pine beetle, Dendroctonus ponderosae, is a significant pest of lodgepole pine in British Columbia (BC), where it has recently reached an unprecedented outbreak level. Although it is native to western North America, the beetle can now be viewed as a native invasive because for the first time in recorded history it has begun to reproduce in native jack pine stands within the North Am...
The white pine weevil, Pissodes strobi Peck (Coleoptera: Curculionidae), is a serious forest pest in young pine and spruce plantations in much of Canada and the northern US (Mitchell et al., 1990; Alfaro et al., 1995). Adults emerge in early spring to begin feeding and egg laying in the secondary phloem of the1-year-old terminal leader of young trees (Silver, 1968). Upon hatching, larvae mine d...
Resin flow is the primary means of natural defense against southern pine beetle (Dendroctonus frontalis Zimm.), the most important insect pest of Pinus spp. in the southern United States. As a result, factors affecting resin flow are of interest to researchers and forest managers. We examined the influence of fertilization, artificial wounding and fungal inoculation on resin flow in 6- and 12-y...
A recent outbreak of mountain pine beetle (MPB) has spread over more than 25 million hectares of pine forests in western North America, affecting pine species of sensitive boreal and mountain ecosystems. During initial host colonization, female MPB produce and release the aggregation pheromone trans-verbenol to coordinate a mass attack of individual trees. trans-Verbenol is formed by hydroxylat...
abstract- to study the effect of tree roots on increasing water infiltration in soil and also to determine and assess the coefficients of different infiltration models, some infiltration tests were performed in three tree plantation areas in badjgah, fars province with different soil textures (clay loam for pear plantation, sandy loam for grape plantation, loamy sand for pine trees). in each pl...
To determine if either herbaceous or woody plants are more competitive with longleaf pine (Pinuspalustris P. Mill.) seedlings, two vegetation management treatments-herbaceous plant control (HPC, No or Yes) and woody plant control (WPC, No or Yes) were applied in newly established longleaf pine plantings in a randomized complete block 2 x 2 factorial design in two studies (a = 0.05). Both studie...
We radiotracked 17 male northern long-eared bats (Myotis septentrionalis) to 43-day roosts and 23 females to 49-day roosts in the Ouachita Mountains of central Arkansas during summers 2000–2005. We compared characteristics of roost trees between males and females, and compared characteristics of sites surrounding roosts with random locations for each sex. Roosts were located in cavities, crevic...
The wood products industry is using herbicides to control competing vegetation, as well as fertilizers to increase growth in southern pine. In 1987, a longterm monitoring study was established to determine the growth potential of loblolly pine (Pinus taeda L.) in the southeastern United States (Borders and Bailey 2001). Very intensive cultural practices were applied including intensive mechanic...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید