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Marazion Marsh
Marazion Marsh is a Royal Society for the Protection of Birds (RSPB) reserve situated in a shallow river valley, half a kilometre to the west of Marazion, Cornwall, UK. It is separated from the coast by a shingle bar and small sand dune system and contains Cornwall's largest reed bed. Geography Marazion Marsh lies to the west of the town of Marazion and east of Penzance. The marsh is in an embayed estuary and is separated from Mount's Bay by a fossilised sand and gravel barrier which (except in extreme weather conditions) prevents access to the marsh by the sea. A discontinuous and eroded sand dune system is crossed by the main Penzance to Marazion road (formally the A394). The recent deposits sit on Lower Devonian Mylor Slates. The Red River (also known as the Marazion River) drains the ''Phragmites'' dominated marsh. The most significant threat to the marsh at present is the runoff of soil particles in the area near the wetland. Because of this, the marsh's catchment is rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society For The Protection Of Birds
The Royal Society for the Protection of Birds (RSPB) is a charitable organisation registered in England and Wales and in Scotland. It was founded in 1889. It works to promote conservation and protection of birds and the wider environment through public awareness campaigns, petitions and through the operation of nature reserves throughout the United Kingdom. In 2020/21 the RSPB had an income of £117 million, 2,000 employees, 12,000 volunteers and 1.1 million members (including 195,000 youth members), making it one of the world's largest wildlife conservation organisations. The RSPB has many local groups and maintains 222 nature reserves. As founders, chief officers and presidents, women have been at the helm of the RSPB for over 85 years. History The origins of the RSPB lie with two groups of women, both formed in 1889: * The Plumage League was founded by Emily Williamson at her house in Didsbury, Manchester, as a protest group campaigning against the use of great crested ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics. Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society Of Arts
The Royal Society for the Encouragement of Arts, Manufactures and Commerce (RSA), also known as the Royal Society of Arts, is a London-based organisation committed to finding practical solutions to social challenges. The RSA acronym is used more frequently than the full legal name (The Royal Society for the Encouragement of Arts, Manufactures and Commerce). The RSA's mission expressed in the founding charter was to "embolden enterprise, enlarge science, refine art, improve our manufacturers and extend our commerce", but also of the need to alleviate poverty and secure full employment. On its website, the RSA characterises itself as "an enlightenment organisation committed to finding innovative practical solutions to today's social challenges". Notable past fellows (before 1914, members) include Charles Dickens, Benjamin Franklin, Stephen Hawking, Karl Marx, Adam Smith, Marie Curie, Nelson Mandela, David Attenborough, Judi Dench, William Hogarth, John Diefenbaker, and Tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victorinus
Marcus Piavonius VictorinusSome of the inscriptions record his name as M. Piavvonius Victorinus, as does the first release of coins from the Colonia mint. A mosaic from Augusta Treverorum (Trier) lists him as Piaonius. was emperor in the Gallic provinces from 268 to 270Martindale, p. 965 or 269 to 271,Polfer, ''Victorinus'' following the brief reign of Marius. He was murdered by a jealous husband whose wife he had tried to seduce. Reign Hailing from Gaul, Victorinus was born to a family of great wealth, and was a soldier under Postumus, the first of the so-called Gallic emperors. He showed considerable ability, as he held the title of tribunus praetorianorum (tribune of the praetorians) in 266/267, and rose swiftly to become co-consul with Postumus in 268.Southern, p. 118 It is also possible that Postumus then elevated him to the post of praetorian prefect.Potter, p. 266 Shortly after putting down a rebellion by Laelianus in 269, Postumus was murdered by his own troops, who a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsh
A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at the edges of lakes and streams, where they form a transition between the aquatic and terrestrial ecosystems. They are often dominated by grasses, rushes or reeds. If woody plants are present they tend to be low-growing shrubs, and the marsh is sometimes called a carr. This form of vegetation is what differentiates marshes from other types of wetland such as swamps, which are dominated by trees, and mires, which are wetlands that have accumulated deposits of acidic peat. Marshes provide habitats for many kinds of invertebrates, fish, amphibians, waterfowl and aquatic mammals. This biological productivity means that marshes contain 0.1% of global sequestered terrestrial carbon. Moreover, they have an outsized influence on climate resi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carr (landform)
A carr is a type of waterlogged wooded terrain that, typically, represents a succession stage between the original reedy marsh and the likely eventual formation of forest in a sub-maritime climate.Whittow, John (1984). ''Dictionary of Physical Geography''. London: Penguin, 1984. . Carrs are wetlands that are dominated by shrubs rather than trees. The carr is one stage in a hydrosere: the progression of vegetation beginning from a terrain submerged by fresh water along a river or lake margin. In sub-maritime regions, it begins with reed-marsh. As the reeds decay, the soil surface eventually rises above the water, creating fens that allow vegetation such as sedge to grow. As this progression continues, riparian trees and bushes appear and a carr landscape is created – in effect a wooded fen in a waterlogged terrain. At this stage, overall, unlike the overwhelming acidity of decaying reeds, the pH is not too acidic and the soil is not too deficient in minerals, making a habitat fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alnus Glutinosa
''Alnus glutinosa'', the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa. It thrives in wet locations where its association with the bacterium ''Frankia alni'' enables it to grow in poor quality soils. It is a medium-sized, short-lived tree growing to a height of up to 30 metres (98 feet). It has short-stalked rounded leaves and separate male and female flowers in the form of catkins. The small, rounded fruits are cone-like and the seeds are dispersed by wind and water. The common alder provides food and shelter for wildlife, with a number of insects, lichens and fungi being completely dependent on the tree. It is a pioneer species, colonising vacant land and forming mixed forests as other trees appear in its wake. Eventually common alder dies out of woodlands because the seedlings need more light than is available on the forest floor. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbaceous
Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of the ''Shorter Oxford English Dictionary'' defines "herb" as: #"A plant whose stem does not become woody and persistent (as in a tree or shrub) but remains soft and succulent, and dies (completely or down to the root) after flowering"; #"A (freq. aromatic) plant used for flavouring or scent, in medicine, etc.". (See: Herb) The same dictionary defines "herbaceous" as: #"Of the nature of a herb; esp. not forming a woody stem but dying down to the root each year"; #"BOTANY Resembling a leaf in colour or texture. Opp. scarious". Botanical sources differ from each other on the definition of "herb". For instance, the Hunt Institute for Botanical Documentation includes the condition "when persisting over more than one growing season, the parts of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Transgression
A marine transgression is a geologic event during which sea level rises relative to the land and the shoreline moves toward higher ground, which results in flooding. Transgressions can be caused by the land sinking or by the ocean basins filling with water or decreasing in capacity. Transgressions and regressions may be caused by tectonic events such as orogenies, severe climate change such as ice ages or isostatic adjustments following removal of ice or sediment load. During the Cretaceous, seafloor spreading created a relatively shallow Atlantic basin at the expense of deeper Pacific basin. That reduced the world's ocean basin capacity and caused a rise in sea level worldwide. As a result of the sea level rise, the oceans transgressed completely across the central portion of North America and created the Western Interior Seaway from the Gulf of Mexico to the Arctic Ocean. The opposite of transgression is regression in which the sea level falls relative to the land and expo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salinity
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ‰). Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a thermodynamic state variable that, along with temperature and pressure, governs physical characteristics like the density and heat capacity of the water. A contour line of constant salinity is called an ''isohaline'', or sometimes ''isohale''. Definitions Salinity in rivers, lakes, and the ocean is conceptually simple, but technically challenging to define and measure precisely. Conceptually the salinity is the quantity of dissolved salt content of the water. Salts are compounds like sodium chloride, magnesium sulfate, potassium nitrate, and sodium bicarbonate which dissolve into ions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Table
The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated. The water table is the surface where the water pressure head is equal to the atmospheric pressure (where gauge pressure = 0). It may be visualized as the "surface" of the subsurface materials that are saturated with groundwater in a given vicinity. The groundwater may be from precipitation or from groundwater flowing into the aquifer. In areas with sufficient precipitation, water infiltrates through pore spaces in the soil, passing through the unsaturated zone. At increasing depths, water fills in more of the pore spaces in the soils, until a zone of saturation is reached. Below the water table, in the phreatic zone (zone of saturation), layers of permeable rock that yield groundwater are called aquifers. In less permeable soils, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Before Present
Before Present (BP) years, or "years before present", is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because the "present" time changes, standard practice is to use 1 January 1950 as the commencement date (epoch) of the age scale. The abbreviation "BP" has been interpreted retrospectively as "Before Physics", which refers to the time before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere, which scientists must now account for. In a convention that is not always observed, many sources restrict the use of BP dates to those produced with radiocarbon dating; the alternative notation RCYBP stands for the explicit "radio carbon years before present". Usage The BP scale is sometimes used for dates established by means other than radiocarbon dating, such as stratigraphy. This usage differs from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
