نتایج جستجو برای: oak tree
تعداد نتایج: 178464 فیلتر نتایج به سال:
Recent mortality in coast live oak (Quercus agrifolia), California black oak (Q. kelloggii), and tanoak (Lithocarpus densiflorus) exceeds historical levels in forests affected by the pathogen Phytophthora ramorum. We assessed the balance between recent mortality and seedling populations in these species to examine the status of regeneration in stands with varying levels of mortality caused by P...
The penetration of solar erythemal ultraviolet radiation has been measured in the shade of a gum (Eucalyptus sp.) and a she oak (Casaurina) tree, both on a horizontal plane and with polysulphone dosimeters to human anatomical sites. This has provided new data useful for protection strategies against harmful ultraviolet radiation. For larger solar zenith angles, the relative penetration of solar...
Acorns are an important wildlife food resource and seed source for oak regeneration. Most acorn production studies note wide and consistent differences in acorn productivity among individuals, but none clearly demonstrate determinants of productivity. Acorn production by black, northern red, scarlet, chestnut and white oak was measured from 1993 to 1997 in the southern Appalachians was measured...
The acorn woodpecker is among the most common primary cavity nesting bird of the Oregon white oak woodlands. In most of their range, acorn woodpeckers are dependent on granaries for acorn storage, yet little is known about their selection of granary sites. We compared habitat characteristics within 12 m of granary and non-granary trees at 20 acorn woodpecker colonies in Benton County, Oregon du...
Advance regeneration in 52 mature mixed-oak stands was analyzed and described. Red maple (Acer rubrum L.) was the most abundant species in the study area. Among oak (Quercus) species, northern red oak (Q. rubra L.) was the most abundant within the Allegheny Plateau physiographic province, whereas chestnut oak (Q. montana L.) was the most abundant within the Ridge and Valley physiographic provin...
To modeling of Suitability Iranian Oak site to establish coppice regenerations, chahartagh forest reserve, Ardal region, chaharmehal and Bakhtiari Province, southern Zagros forest, and southwest Iranian state was selected. To modeling Suitability Iranian Oak used the physiographic element, soil depth, climatology and distance from village selected. To this study used the raster formats by pixel...
To modeling of Suitability Iranian Oak site to establish coppice regenerations, chahartagh forest reserve, Ardal region, chaharmehal and Bakhtiari Province, southern Zagros forest, and southwest Iranian state was selected. To modeling Suitability Iranian Oak used the physiographic element, soil depth, climatology and distance from village selected. To this study used the raster formats by pixel...
The ambrosia beetle, Platypus koryoensis (Murayama), vectors the Korean oak wilt (KOW) pathogen, Raffaelea quercus-mongolicae K.H. Kim, Y.J. Choi, & H.D. Shin, in Korea, which is highly lethal to Mongolian oak, Quercus mongolica Fisch., and is considered a major threat to forest ecosystem health. We characterized the attack pattern of P. koryoensis along the lower trunk of 240 Mongolian oaks i...
Cork oak woodlands (montado) are agroforestry systems distributed all over the Mediterranean basin with a very important social, economic and ecological value. A generalized cork oak decline has been occurring in the last decades jeopardizing its future sustainability. It is unknown how loss of tree cover affects microbial processes that are consuming greenhouse gases in the montado ecosystem. ...
-To compare methods for bottomland hardwood reforestation on marginal farmlands in the Mississippi Alluvial Valley, four afforestation treatments (natural colonization, sown oak acorns, planted oak seedlings, cottonwood–oak interplant) were established in 1995 on former soybean cropland. Natural, sown, and planted-oak plots were not managed after establishment. Interplant plots received intensi...
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