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Hosnies Spring
Hosnies Spring formerly Hosnie's Spring or Hosnies Springs) is a wetland on Christmas Island, an Australian external territory in the eastern Indian Ocean. It has been recognised as being of international importance by designation under the Ramsar Convention on Wetlands. History Hosnies Spring was known earlier but the unique ecosystem was noted in late 1980s. It was incorporated into the Christmas Island National Park in 1989, and listed on 11 December 1990 as Ramsar site 512, one of two such sites on the island and the smallest in the world.Anon (2005). In 2010 a proposal was made to increase the area of the Ramsar site to 202 ha. Justification for its Ramsar designation is because it: * is an example of a type of unusual wetland unique to Christmas Island; * supports a unique assemblage of flora locally restricted to the one location, and additionally several endemic and vulnerable species; * is of special value for locally restricted species as well as several endemics. Alth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ramsar Convention
The Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of Ramsar sites (wetlands). It is also known as the Convention on Wetlands. It is named after the city of Ramsar in Iran, where the convention was signed in 1971. Every three years, representatives of the contracting parties meet as the Conference of the Contracting Parties (COP), the policy-making organ of the convention which adopts decisions (resolutions and recommendations) to administer the work of the convention and improve the way in which the parties are able to implement its objectives. COP12 was held in Punta del Este, Uruguay, in 2015. COP13 was held in Dubai, United Arab Emirates, in October 2018. List of wetlands of international importance The list of wetlands of international importance included 2,331 Ramsar sites in May 2018 covering over . The countries with most sites are the United Kingdo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectonic Uplift
Tectonic uplift is the geologic uplift of Earth's surface that is attributed to plate tectonics. While isostatic response is important, an increase in the mean elevation of a region can only occur in response to tectonic processes of crustal thickening (such as mountain building events), changes in the density distribution of the crust and underlying mantle, and flexural support due to the bending of rigid lithosphere. Tectonic uplift results in denudation (processes that wear away the earth's surface) by raising buried rocks closer to the surface. This process can redistribute large loads from an elevated region to a topographically lower area as well – thus promoting an isostatic response in the region of denudation (which can cause local bedrock uplift). The timing, magnitude, and rate of denudation can be estimated by geologists using pressure-temperature studies. Crustal thickening Crustal thickening has an upward component of motion and often occurs when continental crus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers. They first appeared during the Jurassic Period. Description Crabs are generally covered with a thick exoskeleton, composed primarily of highly mineralized chitin, and armed with a pair of chelae (claws). Crabs vary in size from the pea crab, a few millimeters wide, to the Japanese spider crab, with a leg span up to . Several other groups of crustaceans with similar appearances – such as king crabs and porcelain crabs – are not true crabs, but have evolved features similar to true crabs through a process known as carcinisation. Environment Crabs are found in all of the world's oceans, as well as in fresh w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birds Of Christmas Island
The Birds of Christmas Island form a heterogeneous group of 162 species. There is a core group of 4 endemics that have evolved on the remote island in the eastern Indian Ocean for thousands of years, attended by a suite of regular migrants, opportunists and occasional visitors. Some 200 km from the nearest land, Java, Christmas Island was not occupied by humans until the late 19th century. It is now an Australian territory. The natural vegetation of most of the 140 km² island is rainforest, to which the endemic landbirds are adapted, while the seabirds have taken advantage of a breeding location which had no major natural predators. This list's taxonomic treatment (designation and sequence of orders, families and species) and nomenclature (common and scientific names) follow the conventions of ''The Clements Checklist of Birds of the World'', 2022 edition. The family accounts at the beginning of each heading reflect this taxonomy, as do the species counts in each fam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diameter At Breast Height
Diameter at breast height, or DBH, is a standard method of expressing the diameter of the trunk or bole of a standing tree. DBH is one of the most common dendrometric measurements. Tree trunks are measured at the height of an adult's breast, which is defined differently in different countries and situations. In many countries, DBH is measured at approximately above ground. Global variation and scientific precision The height can make a substantial difference to the measured diameter. In the United States, DBH is typically measured at above ground. In some countries, such as Australia, New Zealand, Burma, India, Malaysia, and South Africa, breast height diameter has historically been measured at a height of , but because of much active research into allometrics that are being applied to trees and forests, the convention of is more appropriate. Ornamental trees are usually measured at 1.5 metres above ground. Some authors have argued that the term DBH should be aboli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruguiera Sexangula
''Bruguiera sexangula'', commonly called the upriver orange mangrove, is a mangrove shrub or tree usually growing up to 15 m, occasionally 30 m, in height. Description ''Bruguiera sexangula'' may grow as a single-stemmed tree or multi-stemmed shrub. It has short buttresses at the base of the trunk, and knee-like air-breathing roots, or pneumatophores. The bark is a smooth grey-brown colour. The smooth, glossy green leaves are simple and opposite, elliptic to elliptic-oblong, 9.5–20 cm long, 3–7 cm wide, with a pointed apex and a 6 cm petiole, occurring in clusters at the end of the branches.Mangrove Web. The flowers have a pale yellow-green to pinkish-orange calyx with 12–14 lobes, 20–24 stamens and 10–12 creamy-orange, bi-lobed petals. The green, cigar-shaped viviparous propagule grows from within the calyx and is 5–12 cm long and 1–2 cm wide. Distribution and habitat This mangrove is distributed eastwards along the tropical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruguiera Gymnorhiza
''Bruguiera gymnorhiza'', the large-leafed orange mangrove or oriental mangrove,) is a mangrove tree that grows usually to 7-20m high, but sometimes up to 35m, that belongs to the family Rhizophoraceae. It is found on the seaward side of mangrove swamps, often in the company of ''Rhizophora''. It grows from the Western Pacific across Indian Ocean coasts to Cape Province, South Africa. Description A tree that can grow up to 35m, though usually smaller, around 7-20m, it has a glabrous, smoothish, trunk with reddish brown bark (the bark is sometimes fibrous, sometimes lightish brown or grey). The tree develops short prop-roots rather than long stilt-roots. The green elliptic leaves are 5–15 cm long. Flowers are solitary, with white or cream petals, that soon turn brown up to 1.5 cm long, pinkish-green to reddish brown calyx. The fruit are turbinate (spinning-top shaped), 2 cm long, when mature, the spindle-shaped fruits drop and become embedded in the mud in an upr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mangrove
A mangrove is a shrub or tree that grows in coastal saline water, saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evolution in several plant families. They occur worldwide in the tropics and subtropics and even some temperate coastal areas, mainly between latitudes 30° N and 30° S, with the greatest mangrove area within 5° of the equator. Mangrove plant families first appeared during the Late Cretaceous to Paleocene epochs, and became widely distributed in part due to the plate tectonics, movement of tectonic plates. The oldest known fossils of Nypa fruticans, mangrove palm date to 75 million years ago. Mangroves are salt-tolerant trees, also called halophytes, and are adapted to live in harsh coastal conditions. They contain a complex salt filtration system and a complex root system to cope with saltwater immersion and wave action. They are ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring (hydrosphere)
A spring is a point of exit at which groundwater from an aquifer flows out on top of Earth's crust (pedosphere) and becomes surface water. It is a component of the hydrosphere. Springs have long been important for humans as a source of fresh water, especially in arid regions which have relatively little annual rainfall. Springs are driven out onto the surface by various natural forces, such as gravity and hydrostatic pressure. Their yield varies widely from a volumetric flow rate of nearly zero to more than for the biggest springs. Formation Springs are formed when groundwater flows onto the surface. This typically happens when the groundwater table reaches above the surface level. Springs may also be formed as a result of karst topography, aquifers, or volcanic activity. Springs also have been observed on the ocean floor, spewing hot water directly into the ocean. Springs formed as a result of karst topography create karst springs, in which ground water travels throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Above Mean Sea Level
Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The combination of unit of measurement and the physical quantity (height) is called "metres above mean sea level" in the metric system, while in United States customary and imperial units it would be called "feet above mean sea level". Mean sea levels are affected by climate change and other factors and change over time. For this and other reasons, recorded measurements of elevation above sea level at a reference time in history might differ from the actual elevation of a given location over sea level at a given moment. Uses Metres above sea level is the standard measurement of the elevation or altitude of: * Geographic locations such as towns, mountains and other landmarks. * The top of buildings and other structures. * Flying objects such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Terrace
A raised beach, coastal terrace,Pinter, N (2010): 'Coastal Terraces, Sealevel, and Active Tectonics' (educational exercise), from 2/04/2011/ref> or perched coastline is a relatively flat, horizontal or gently inclined surface of marine origin,Pirazzoli, PA (2005a): 'Marine Terraces', in Schwartz, ML (ed) ''Encyclopedia of Coastal Science.'' Springer, Dordrecht, pp. 632–633 mostly an old abrasion platform which has been lifted out of the sphere of wave activity (sometimes called "tread"). Thus, it lies above or under the current sea level, depending on the time of its formation.Strahler AH; Strahler AN (2005): ''Physische Geographie.'' Ulmer, Stuttgart, 686 p.Leser, H (ed)(2005): ‚''Wörterbuch Allgemeine Geographie.'' Westermann&Deutscher Taschenbuch Verlag, Braunschweig, 1119 p. It is bounded by a steeper ascending slope on the landward side and a steeper descending slope on the seaward side (sometimes called "riser"). Due to its generally flat shape, it is often used for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cliff
In geography and geology, a cliff is an area of rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually composed of rock that is resistant to weathering and erosion. The sedimentary rocks that are most likely to form cliffs include sandstone, limestone, chalk, and dolomite. Igneous rocks such as granite and basalt also often form cliffs. An escarpment (or scarp) is a type of cliff formed by the movement of a geologic fault, a landslide, or sometimes by rock slides or falling rocks which change the differential erosion of the rock layers. Most cliffs have some form of scree slope at their base. In arid areas or under high cliffs, they are generally exposed jumbles of fallen rock. In areas of higher moisture, a soil slope may obscure the talus. Many cliffs also fea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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