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Balsam Woolly Adelgid
Balsam woolly adelgids (''Adelges piceae'') are small wingless insects that infest and kill firs, especially balsam fir and Fraser fir. They are an invasive species from Europe introduced to the United States around 1900. Because this species is not native to the United States, the Fraser fir has not evolved any type of defense against it. Reproduction These insects typically lay about one hundred eggs and have three generations per year. The adelgid attacks the tree by feeding in fissures within the bark of trees larger than about four centimeters in diameter at breast height. As it feeds, it releases toxins contained within its saliva. These toxins reduce the conductance of sapwood being built, which causes water stress and kills the trees. Impact The Great Smoky Mountains National Park, straddling North Carolina and Tennessee in the Southeastern United States, contains about 75% of all southern spruce-fir ecosystems. These ecosystems covered vast portions of the Southea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julius Theodor Christian Ratzeburg
Julius Theodor Christian Ratzeburg (16 February 1801– 24 October 1871) was a German zoologist, botanist, entomologist, and forester. Biography Ratzeburg was born in Berlin, the son of a professor at the veterinary school of the University of Berlin. He studied medicine and natural sciences in Berlin and was primarily interested in botany. He became a private lecturer at the University of Berlin in 1828, when he was in contact with Alexander and Wilhelm von Humboldt. Two years later, he became professor of natural history there at the invitation of Friedrich Wilhelm Leopold Pfeil (1783-1859). He founded the botanic garden of forestry at Eberswalde, working there until his retirement in 1869. He returned to Berlin, where he resided until his death. Ratzeburg was the author of important works on forestry and forest entomology, and is considered the founder of the latter discipline. He was notably interested in parasitic species. From 1827 to 1834, he wrote ''Medizinische Zoo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canopy (forest)
In biology, the canopy is the aboveground portion of a plant cropping or crop, formed by the collection of individual plant crowns. In forest ecology, canopy also refers to the upper layer or habitat zone, formed by mature tree crowns and including other biological organisms (epiphytes, lianas, arboreal animals, etc.). The communities that inhabit the canopy layer are thought to be involved in maintaining forest diversity, resilience, and functioning. Sometimes the term canopy is used to refer to the extent of the outer layer of leaves of an individual tree or group of trees. Shade trees normally have a dense canopy that blocks light from lower growing plants. Observation Early observations of canopies were made from the ground using binoculars or by examining fallen material. Researchers would sometimes erroneously rely on extrapolation by using more reachable samples taken from the understory. In some cases, they would use unconventional methods such as chairs sus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washington (U
Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered on Washington, D.C. * George Washington (1732–1799), the first president of the United States Washington may also refer to: Places England * Washington, Tyne and Wear, a town in the City of Sunderland metropolitan borough ** Washington Old Hall, ancestral home of the family of George Washington * Washington, West Sussex, a village and civil parish Greenland * Cape Washington, Greenland * Washington Land Philippines * New Washington, Aklan, a municipality *Washington, a barangay in Catarman, Northern Samar *Washington, a barangay in Escalante, Negros Occidental *Washington, a barangay in San Jacinto, Masbate *Washington, a barangay in Surigao City United States * Washington, Wisconsin (other) * Fort Washington ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subalpine Fir
''Abies lasiocarpa'', the subalpine fir or Rocky Mountain fir, is a western North American fir tree. Description ''Abies lasiocarpa'' is a medium-sized evergreen conifer with a very narrow conic crown, growing to tall, exceptionally , with a trunk up to thick, exceptionally . The bark on young trees is smooth, gray, and with resin blisters, becoming rough and fissured or scaly on old trees. The lowest branches can be observed growing above ground level. The leaves are flat and needle-like, long, glaucous green above with a broad stripe of stomata, and two blue-white stomatal bands below; the fresh leaf scars are reddish (tan on the inland variety). They are arranged spirally on the shoot, but with the leaf bases twisted to be arranged to the sides of and above the shoot, with few or none below the shoot. The cones are erect, long, dark purple with fine yellow-brown pubescence, ripening brown and disintegrating to release the winged seeds in early fall. Taxonomy There are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abies Amabilis
''Abies amabilis'', commonly known as the Pacific silver fir, is a fir native to the Pacific Northwest of North America, occurring in the Pacific Coast Ranges and the Cascade Range. It is also commonly referred to as the white fir, red fir, lovely fir, Amabilis fir, Cascades fir, or silver fir. The species name is Latin for 'lovely'. Description The tree is a large evergreen conifer growing to , exceptionally tall, and with a trunk diameter of up to , exceptionally . The bark on younger trees is light grey, thin and covered with resin blisters. On older trees, it darkens and develops scales and furrows. The leaves are needle-like, flattened, long and wide by thick, matte dark green above, and with two white bands of stomata below, and slightly notched at the tip. The leaf arrangement is spiral on the shoot, but with each leaf variably twisted at the base so they lie flat to either side of and above the shoot, with none below the shoot. The shoots are orange-red with dense ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grand Fir
''Abies grandis'' (grand fir, giant fir, lowland white fir, great silver fir, western white fir, Vancouver fir, or Oregon fir) is a fir native to the Pacific Northwest and Northern California of North America, occurring at altitudes of sea level to . It is a major constituent of the Grand Fir/Douglas Fir Ecoregion of the Cascade Range. The tree typically grows to in height, and may be the tallest ''Abies'' species in the world. There are two varieties, the taller coast grand fir, found west of the Cascade Mountains, and the shorter interior grand fir, found east of the Cascades. It was first described in 1831 by David Douglas. It is closely related to white fir. The bark was historically believed to have medicinal properties, and it is popular in the United States as a Christmas tree. Its lumber is a softwood, and it is harvested as a hem fir. It is used in paper-making, as well as construction for framing and flooring, where it is desired for its resistance to splitting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spruce-fir Moss Spider
The spruce-fir moss spider (''Microhexura montivaga'') is an endangered species of spider found at high elevations in the southern Appalachian Mountains. First identified in 1923, it inhabits moss that grows on rocks underneath the forest canopy. Description ''M. montivaga'' is one of the smallest mygalomorph spiders, with adults only measuring 3 to 4 mm (about 1/8 inch). The coloration varies from light brown to yellow-brown to a darker reddish brown, with no markings on the abdomen. The chelicerae project forward, and one pair of spinnerets is very long. It possesses a second pair of book lungs, which appear as light patches behind the genital furrow. Distribution and habitat ''M. multivaga'' is known from Fraser fir and red spruce forests on mountain peaks at and above in the Southern Appalachian Mountains of North Carolina, Virginia and Tennessee. It has been recorded from Clingmans Dome and Mount Collins (both very small populations), Mount Le Conte, Mount Mitc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollutant
A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oil) or anthropogenic in origin (i.e. manufactured materials or byproducts from biodegradation). Pollutants result in environmental pollution or become public health concerns when they reach a concentration high enough to have significant negative impacts. A pollutant may cause long- or short-term damage by changing the growth rate of plant or animal species, or by interfering with human amenities, comfort, health, or property values. Some pollutants are biodegradable and therefore will not persist in the environment in the long term. However, the degradation products of some pollutants are themselves polluting such as the products DDE and DDD produced from the degradation of DDT. Pollution has widespread negative impacts on the envir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ozone
Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lower atmosphere to ( dioxygen). Ozone is formed from dioxygen by the action of ultraviolet (UV) light and electrical discharges within the Earth's atmosphere. It is present in very low concentrations throughout the latter, with its highest concentration high in the ozone layer of the stratosphere, which absorbs most of the Sun's ultraviolet (UV) radiation. Ozone's odour is reminiscent of chlorine, and detectable by many people at concentrations of as little as in air. Ozone's O3 structure was determined in 1865. The molecule was later proven to have a bent structure and to be weakly diamagnetic. In standard conditions, ozone is a pale blue gas that condenses at cryogenic temperatures to a dark blue liquid and finally a violet-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Rain
Acid rain is rain or any other form of precipitation that is unusually acidic, meaning that it has elevated levels of hydrogen ions (low pH). Most water, including drinking water, has a neutral pH that exists between 6.5 and 8.5, but acid rain has a pH level lower than this and ranges from 4–5 on average. The more acidic the acid rain is, the lower its pH is. Acid rain can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulphur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids. Acid rain has been shown to have adverse impacts on forests, freshwaters, soils, microbes, insects and aquatic life-forms. In ecosystems, persistent acid rain reduces tree bark durability, leaving flora more susceptible to environmental stressors such as drought, heat/cold and pest infestation. Acid rain is also capable of detrimenting soil composition by stripping it of nutrients such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asheville Citizen-Times
The ''Asheville Citizen-Times'' is an American, English language daily newspaper of Asheville, North Carolina. It was formed in 1991 as a result of a merger of the morning ''Asheville Citizen'' and the afternoon ''Asheville Times''. It is owned by Gannett. History Founded in 1870 as a weekly, the ''Citizen'' became a daily newspaper in 1885. Writers Thomas Wolfe, O. Henry, both buried in Asheville, and F. Scott Fitzgerald, a common visitor to Asheville, frequently could be found in the newsroom in earlier days. In 1930 the ''Citizen'' came under common ownership with the ''Times'', which was first established in 1896 as the ''Asheville Gazette''. The latter paper merged with a short-lived rival, the ''Asheville Evening News'', to form the ''Asheville Gazette-News'' and was renamed ''The Asheville Times'' by new owner Charles A. Webb. The ''Citizen'' was in a former YMCA and the press was in the swimming pool. The ''Times'' was in the Jackson Building. The ''Citizen'' had to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Spruce
''Picea rubens'', commonly known as red spruce, is a species of spruce native to eastern North America, ranging from eastern Quebec and Nova Scotia, west to the Adirondack Mountains and south through New England along the Appalachians to western North Carolina.Farjon, A. (1990). ''Pinaceae. Drawings and Descriptions of the Genera''. Koeltz Scientific Books . This species is also known as yellow spruce, West Virginia spruce, eastern spruce, and he-balsam. Description Red spruce is a perennial, shade-tolerant, late successional coniferous tree that under optimal conditions grows to tall with a trunk diameter of about , though exceptional specimens can reach tall and in diameter. It has a narrow conical crown. The leaves are needle-like, yellow-green, long, four-sided, curved, with a sharp point, and extend from all sides of the twig. The bark is gray-brown on the surface and red-brown on the inside, thin, and scaly. The wood is light, soft, has narrow rings, and has a sligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
