|
Coarse Woody Debris
Coarse woody debris (CWD) or coarse woody habitat (CWH) refers to fallen dead trees and the remains of large branches on the ground in forests and in rivers or wetlands.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p, p. 225-227. A dead standing tree – known as a snag – provides many of the same functions as coarse woody debris. The minimum size required for woody debris to be defined as "coarse" varies by author, ranging from in diameter. Since the 1970s, forest managers worldwide have been encouraged to allow dead trees and woody debris to remain in woodlands, recycling nutrients trapped in the wood and providing food and habitat for a wide range of organisms, thereby improving biodiversity. The amount of coarse woody debris is considered an important criterion for the evaluation and restoration of temperate deciduous forest. Coarse woody debris is also important in wetlands, particularly in d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Woodland
In the United Kingdom, an ancient woodland is a woodland that has existed continuously since 1600 or before in England, Wales and Northern Ireland (or 1750 in Scotland). Planting of woodland was uncommon before those dates, so a wood present in 1600 is likely to have developed naturally. In most ancient woods, the trees and shrubs have been cut down periodically as part of the management cycle. Provided that the area has remained as woodland, the stand is still considered ancient. Since it may have been cut over many times in the past, ancient woodland does not necessarily contain very old trees. For many species of animal and plant, ancient woodland sites provide the sole habitat, and for many others, conditions on these sites are much more suitable than those on other sites. Ancient woodland in the UK, like rainforest in the tropics, is home to rare and threatened species. For these reasons ancient woodland is often described as an irreplaceable resource, or 'critical natural c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium
Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals, all of which have a single valence electron in the outer electron shell, that is easily removed to create an ion with a positive charge – a cation, that combines with anions to form salts. Potassium in nature occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac- colored flame. It is found dissolved in sea water (which is 0.04% potassium by weight), and occurs in many minerals such as orthocl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen Cycle
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmospheric nitrogen, making it the largest source of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems. The nitrogen cycle is of particular interest to ecologists because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition. Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Cycle
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Carbon is the main component of biological compounds as well as a major component of many minerals such as limestone. Along with the nitrogen cycle and the water cycle, the carbon cycle comprises a sequence of events that are key to make Earth capable of sustaining life. It describes the movement of carbon as it is recycled and reused throughout the biosphere, as well as long-term processes of carbon sequestration to and release from carbon sinks. Carbon sinks in the land and the ocean each currently take up about one-quarter of anthropogenic carbon emissions each year. Humans have disturbed the biological carbon cycle for many centuries by modifying land use, and moreover with the recent industrial-scale mining of fossil carbon (coal, petroleum and gas extraction, and cement manufacture) from the geosphere. Carbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decomposition
Decomposition or rot is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is essential for recycling the finite matter that occupies physical space in the biosphere. Bodies of living organisms begin to decompose shortly after death. Animals, such as worms, also help decompose the organic materials. Organisms that do this are known as decomposers or detritivores. Although no two organisms decompose in the same way, they all undergo the same sequential stages of decomposition. The science which studies decomposition is generally referred to as ''taphonomy'' from the Greek word ''taphos'', meaning tomb. Decomposition can also be a gradual process for organisms that have extended periods of dormancy. One can differentiate abiotic decomposition from biotic decomposition ( biodegradation). The former means "the degradat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forests Of Australia
Australia has many forests of importance due to significant features, despite being one of the driest continents. , Australia has approximately 147 million hectares of native forest, which represents about 19% of Australia's land area. The majority of Australia's trees are hardwoods, typically eucalypts, rather than softwoods like pine. While softwoods dominate some native forests, their total area is judged insufficient to constitute a major forest type iAustralia's National Forest Inventory ThForests Australiawebsite provides up-to-date information on Australia's forests. Detailed information on Australia's forests is available froAustralia's State of the Forests Reportsthat are published every five years. Forest types There are 458 forest communities distributed across Australia. These have been grouped into the following seven native forest types, which are characterised by dominant species and the structure of the forest: * Rainforests * Melaleuca forests * Eucalypt forest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Plate, North American Tectonic Plate, Greenland is included as a part of North America geographically. North America covers an area of about , about 16.5% of Earth's land area and about 4.8% of its total surface. North America is the third-largest continent by area, following Asia and Africa, and the list of continents and continental subregions by population, fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in List of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's population. In Americas (terminology)#Human ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Northwest
The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though no official boundary exists, the most common conception includes the U.S. states of Oregon, Washington, and Idaho, and the Canadian province of British Columbia. Some broader conceptions reach north into Alaska and Yukon, south into northern California, and east into western Montana. Other conceptions may be limited to the coastal areas west of the Cascade and Coast mountains. The variety of definitions can be attributed to partially overlapping commonalities of the region's history, culture, geography, society, ecosystems, and other factors. The Northwest Coast is the coastal region of the Pacific Northwest, and the Northwest Plateau (also commonly known as " the Interior" in British Columbia and the Inland Northwest in the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudotsuga Menziesii
The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three varieties: coast Douglas-fir (''P. menziesii'' var. ''menziesii''), Rocky Mountain Douglas-fir (''P. menziesii'' var. ''glauca'') and Mexican Douglas-fir (''P. menziesii'' var. ''lindleyana''). Despite its common names, it is not a true fir (genus ''Abies''), spruce (genus ''Picea''), or pine (genus ''Pinus''). It is also not a hemlock; the genus name ''Pseudotsuga'' means "false hemlock". Description Douglas-firs are medium-size to extremely large evergreen trees, tall (although only ''Pseudotsuga menziesii var. menziesii'', common name coast Douglas-firs, reach heights near 100 m) and commonly reach in diameter, although trees with diameters of almost exist. The largest coast Douglas-firs regularly live over 500 years, with the ol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coppicing
Coppicing is a traditional method of woodland management which exploits the capacity of many species of trees to put out new shoots from their stump or roots if cut down. In a coppiced wood, which is called a copse, young tree stems are repeatedly cut down to near ground level, resulting in a stool. New growth emerges, and after a number of years, the coppiced tree is harvested, and the cycle begins anew. Pollarding is a similar process carried out at a higher level on the tree in order to prevent grazing animals from eating new shoots. '' Daisugi'' (台杉, where ''sugi'' refers to Japanese cedar), is a similar Japanese technique. Many silviculture practices involve cutting and regrowth; coppicing has been of significance in many parts of lowland temperate Europe. The widespread and long-term practice of coppicing as a landscape-scale industry is something that remains of special importance in southern England. Many of the English language terms referenced in this article are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> North America")
