|
Chalk Streams
Chalk streams are rivers that rise from springs in landscapes with chalk bedrock. Since chalk is permeable, water easily percolates through the ground to the water table and chalk streams therefore receive little surface runoff. As a result, the water in the streams contains little organic matter and sediment and is generally very clear. The beds of the rivers are generally composed of clean, compacted gravel and flints, which provide good spawning grounds for Salmonidae fish species. Since they are primarily fed by aquifers, the flow rate, mineral content and temperature range of chalk streams shows less seasonal variation than other rivers. They are mildly alkaline and contain high levels of nitrate, phosphate, potassium and silicate. In addition to algae and diatoms, the streams provide a suitable habitat for macrophytes (including water crowfoot) and oxygen levels are generally supportive of coarse fish populations. Of the 210 rivers classified as chalk streams glo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalkstream
Chalk streams are rivers that rise from springs in landscapes with chalk bedrock. Since chalk is permeable, water easily percolates through the ground to the water table and chalk streams therefore receive little surface runoff. As a result, the water in the streams contains little organic matter and sediment and is generally very clear. The beds of the rivers are generally composed of clean, compacted gravel and flints, which provide good spawning grounds for Salmonidae fish species. Since they are primarily fed by aquifers, the flow rate, mineral content and temperature range of chalk streams shows less seasonal variation than other rivers. They are mildly alkaline and contain high levels of nitrate, phosphate, potassium and silicate. In addition to algae and diatoms, the streams provide a suitable habitat for macrophytes (including water crowfoot) and oxygen levels are generally supportive of coarse fish populations. Of the 210 rivers classified as chalk streams global ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquifer
An aquifer is an underground layer of water-bearing material, consisting of permeability (Earth sciences), permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The study of water flow in aquifers and the characterization of aquifers is called ''hydrogeology''. Related concepts include aquitard, a bed (geology), bed of low permeability along an aquifer, and aquiclude (or ''aquifuge''), a solid and impermeable region underlying or overlying an aquifer, the pressure of which could lead to the formation of a confined aquifer. Aquifers can be classified as saturated versus unsaturated; aquifers versus aquitards; confined versus unconfined; isotropic versus anisotropic; porous, karst, or fractured; and transboundary aquifer. Groundwater from aquifers can be sustainably harvested by humans through the use of qanats leading to a well. This groundwater is a major source of fresh water for many regions, althoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United Kingdom Biodiversity Action Plan
The United Kingdom Biodiversity Action Plan (UK BAP) was the UK government's response to the Convention on Biological Diversity, opened for signature at the Rio Earth Summit in 1992. The UK was the first country to produce a national Biodiversity Action Plan. It was published in 1994 and created action plans for priority species and habitats in the UK that were most under threat so as to support their recovery. Purpose The UK Biodiversity Action Plan summarised the most threatened or rapidly declining biological resources of the United Kingdom, and gave detailed plans for their conservation. Individual 'Action Plans' were provided for these habitats and species, and a reporting mechanism was established to demonstrate how the UK BAP was contributing to the United Kingdom's commitment to help reduce or halt the significant losses in global biodiversity, highlighted by the international Convention on Biological Diversity. The original publication included action plans for 45 habi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural England
Natural England is a non-departmental public body in the United Kingdom sponsored by the Department for Environment, Food and Rural Affairs. It is responsible for ensuring that England's natural environment, including its land, flora and fauna, freshwater and marine environments, geology and soils, are protected and enhanced. It also has a responsibility to help people enjoy, understand and access the natural environment. Natural England focuses its activities and resources on four strategic outcomes: * a healthy natural environment * enjoyment of the natural environment * sustainable use of the natural environment * a secure environmental future Roles and responsibilities As a non-departmental public body (NDPB), Natural England is independent of government. However, the Secretary of State for Environment, Food & Rural Affairs has the legal power to issue guidance to Natural England on various matters. Its powers include defining ancient woodlands, awarding grants, designatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environment Agency
The Environment Agency (EA) is a non-departmental public body, established in 1996 and sponsored by the United Kingdom government's Department for Environment, Food and Rural Affairs, with responsibilities relating to the protection and enhancement of the environment (biophysical), environment in England (and until 2013 also Wales). Based in Bristol, the Environment Agency is responsible for flood management, waste management, regulating land and water pollution, and conservation. Roles and responsibilities Purpose The Environment Agency's stated purpose is, "to protect or enhance the environment, taken as a whole" so as to promote "the objective of achieving sustainable development" (taken from the Environment Act 1995, section 4). Protection of the environment relates to threats such as flood and pollution. The vision statement, vision of the agency is of "a rich, healthy and diverse environment for present and future generations". Scope The Environment Agency's remit c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coarse Fishing
Coarse fishing (, ) is a phrase commonly used in United Kingdom, Great Britain and Ireland. It refers to the angling for rough fish, which are fish species considered undesirable as food or game fish. Freshwater game fish are all salmonids, particularly salmon, trout and Salvelinus, char. Generally, coarse fish are freshwater fish that are not salmonids, though there is often disagreement over whether Thymallus, grayling should be classified as a game fish or a coarse fish. Fly fishing is the technique usually used for freshwater game fishing, while other angling techniques are usually used for coarse fishing. The sport of coarse fishing and its techniques are particularly popular in the United Kingdom and mainland Europe, as well as in some former British Commonwealth of Nations, Commonwealth countries and among British expatriates. The distinction between coarse fish and game fish, terms that developed in the United Kingdom in the early 19th century, has no taxonomic basis Bob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygenation (environmental)
Hypoxia (''hypo'': 'below', ''oxia'': 'oxygenated') refers to low oxygen conditions. Hypoxia is problematic for air-breathing organisms, yet it is essential for many anaerobic organisms. Hypoxia applies to many situations, but usually refers to the atmosphere and natural waters. Atmospheric hypoxia Atmospheric hypoxia occurs naturally at high altitudes. Total atmospheric pressure decreases as altitude increases, causing a lower partial pressure of oxygen, which is defined as hypobaric hypoxia. Oxygen remains at 20.9% of the total gas mixture, differing from hypoxic hypoxia, where the percentage of oxygen in the air (or blood) is decreased. This is common in the sealed burrows of some subterranean animals, such as blesmol The blesmols, also known as mole-rats, or African mole-rats, are burrowing rodents of the family Bathyergidae. They represent a distinct evolution of a Subterranean fauna, subterranean life among rodents much like the pocket gophers of North Am ...s. At ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ranunculus
''Ranunculus'' is a large genus of about 1750 species of flowering plants in the family Ranunculaceae. Members of the genus are known as buttercups, spearworts and water crowfoots. The genus is distributed worldwide, primarily in temperate and montane regions. The familiar and widespread buttercup of gardens throughout Northern Europe (and introduced elsewhere) is the creeping buttercup '' Ranunculus repens'', which has extremely tough and tenacious roots. Two other species are also widespread, the bulbous buttercup '' Ranunculus bulbosus'' and the much taller meadow buttercup '' Ranunculus acris''. In ornamental gardens, all three are often regarded as weeds. Buttercups usually flower in the spring, but flowers may be found throughout the summer, especially where the plants are growing as opportunistic colonizers, as in the case of garden weeds. The water crowfoots (''Ranunculus'' subgenus ''Batrachium''), which grow in still or running water, are sometimes treated in a sep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Plants
Aquatic plants, also referred to as hydrophytes, are vascular plants and non-vascular plants that have adapted to live in aquatic environments ( saltwater or freshwater). In lakes, rivers and wetlands, aquatic vegetations provide cover for aquatic animals such as fish, amphibians and aquatic insects, create substrate for benthic invertebrates, produce oxygen via photosynthesis, and serve as food for some herbivorous wildlife. Familiar examples of aquatic plants include waterlily, lotus, duckweeds, mosquito fern, floating heart, water milfoils, mare's tail, water lettuce, water hyacinth, and algae. Aquatic plants require special adaptations for prolonged inundation in water, and for floating at the water surface. The most common adaptation is the presence of lightweight internal packing cells, aerenchyma, but floating leaves and finely dissected leaves are also common.Sculthorpe, C. D. 1967. The Biology of Aquatic Vascular Plants. Reprinted 1985 Edward Arnold, by London.Hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatom
A diatom (Neo-Latin ''diatoma'') is any member of a large group comprising several Genus, genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of Earth's Biomass (ecology), biomass. They generate about 20 to 50 percent of the oxygen produced on the planet each year, take in over 6.7 billion tonnes of silicon each year from the waters in which they live, and constitute nearly half of the organic material found in the oceans. The Protist shell, shells of dead diatoms are a significant component of marine sediment, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up of a system of fresh-water lakes. Diatoms are unicellular organisms: they occur either as solitary cells or in Colony (biology), colonies, which can take the shape of ribb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, such as cyanobacteria, ''Chlorella'', and diatoms, to multicellular macroalgae such as kelp or brown algae which may grow up to in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem that are found in embryophyte, land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a Division (taxonomy), division of green algae which includes, for example, ''Spirogyra'' and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton. Algae constitute a Polyphyly, polyphyletic group because they do not include a common ancestor, and although Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicate
A silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name is also used for any salt of such anions, such as sodium metasilicate; or any ester containing the corresponding chemical group, such as tetramethyl orthosilicate. The name "silicate" is sometimes extended to any anions containing silicon, even if they do not fit the general formula or contain other atoms besides oxygen; such as hexafluorosilicate . Most commonly, silicates are encountered as silicate minerals. For diverse manufacturing, technological, and artistic needs, silicates are versatile materials, both natural (such as granite, gravel, and garnet) and artificial (such as Portland cement, ceramics, glass, and waterglass). Structural principles In most silicates, a silicon atom occupies the center of an idealized tetrahedron whose cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
