|
Leersia Hexandra
''Leersia hexandra'' is a species of grass known by the common names southern cutgrass, clubhead cutgrass, and swamp rice grass.''Leersia hexandra''. Pacific Island Ecosystems at Risk (PIER). It has a distribution. It is also an in many regions, sometimes becoming invasive, and it is an agricultural weed of various crops, especially |
Olof Swartz
Olof Peter Swartz (21 September 1760 – 19 September 1818) was a Swedish botanist and taxonomist. He is best known for his taxonomic work and studies into pteridophytes. Biography Olof Swartz attended the University of Uppsala where he studied under Carl Linnaeus the Younger (1741–1783) and received his doctorate in 1781. He first traveled in 1780 to Lapland in the company of several other botanists. In 1783 he sailed for North America and the West Indies, primarily in the area of Jamaica and Hispaniola, to collect botanical specimens. His botanical collection, of an impressive 6000 specimens, is now held by the Swedish Museum of Natural History, as part of the Regnellian herbarium. By 1786 he left for London to prepare his collection. There he met naturalist Joseph Banks (1743–1820), who was impressed with his knowledge of Botany. He was offered a position with the British East India Company as a travelling physician, but turned it down, and returned to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oryza
''Oryza'' is a genus of plants in the grass family. It includes the major food crop rice (species ''Oryza sativa'' and ''Oryza glaberrima''). Members of the genus grow as tall, wetland grasses, growing to tall; the genus includes both annual and perennial species. ''Oryza'' is situated in tribe Oryzeae, which is characterized morphologically by its single-flowered spikelets whose glumes are almost completely suppressed. In ''Oryza'', two sterile lemma simulate glumes. The tribe Oryzeae is in subfamily Ehrhartoideae, a group of Poaceae tribes with certain features of internal leaf anatomy in common. The most distinctive leaf characteristics of this subfamily are the arm cells and fusoid cells found in their leaves.Heywood, V.H. Flowering Plants of the World 1993 Oxford University Press One species, Asian rice ( ''O. sativa''), provides 20% of global grain and is a food crop of major global importance. The species are divided into two subgroups within the genus. Species Inside ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dominance (ecology)
Ecological dominance is the degree to which one or several species have a major influence controlling the other species in their ecological community (because of their large size, population, productivity, or related factors) or make up more of the biomass. Most ecological communities are defined by their dominant species. *In many examples of wet woodland in western Europe, the dominant tree is alder ('' Alnus glutinosa''). *In temperate bogs, the dominant vegetation is usually species of ''Sphagnum ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, peat moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store wa ...'' moss. *Tide, Tidal swamps in the tropics are usually dominated by species of mangrove (''Rhizophoraceae'') *Some sea floor communities are dominated by brittle stars. *Exposed rocky shorelines are dominated by Sessility (zool ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and the Indian Ocean to the east; Mozambique and Malawi to the south; Zambia to the southwest; and Rwanda, Burundi, and the Democratic Republic of the Congo to the west. Mount Kilimanjaro, Africa's highest mountain, is in northeastern Tanzania. According to the United Nations, Tanzania has a population of million, making it the most populous country located entirely south of the equator. Many important hominid fossils have been found in Tanzania, such as 6-million-year-old Pliocene hominid fossils. The genus Australopithecus ranged across Africa between 4 and 2 million years ago, and the oldest remains of the genus '' Homo'' are found near Lake Olduvai. Following the rise of '' Homo erectus'' 1.8 million years ago, humanit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Bird
A water bird, alternatively waterbird or aquatic bird, is a bird that lives on or around water. In some definitions, the term ''water bird'' is especially applied to birds in freshwater ecosystems, although others make no distinction from seabirds that inhabit marine environments. Some water birds (e.g. wading birds) are more terrestrial while others (e.g. waterfowls) are more aquatic, and their adaptations will vary depending on their environment. These adaptations include webbed feet, beaks, and legs adapted to feed in the water, and the ability to dive from the surface or the air to catch prey in water. The term ''aquatic bird'' is sometimes also used in this context. A related term that has a narrower meaning is waterfowl. Some piscivorous birds of prey, such as ospreys and sea eagles, hunt aquatic prey but do not stay in water for long and lives predominantly over dry land, and are not considered water birds. The term waterbird is also used in the context of conservati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drought
A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, and O. Zolina, 2021Water Cycle Changes In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1055–1210, doi:10.1017/9781009157896.010. This means that a drought is "a moisture deficit relative to the average water availability at a given location and season". A drought can last for days, months or years. Drought ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperate Climate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout the year and more distinct seasonal changes compared to tropical climates, where such variations are often small and usually only have precipitation changes. In temperate climates, not only do latitudinal positions influence temperature changes, but sea currents, prevailing wind direction, continentality (how large a landmass is) and altitude also shape temperate climates. The Köppen climate classification defines a climate as "temperate" C, when the mean temperature is above but below in the coldest month to account for the persistency of frost. However, other climate classifications set the minimum at . Zones and climates The north temperate zone extends from the Tropic of Cancer (approximately 23.5° north latitude) to the Arct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropics
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to as the tropical zone and the torrid zone (see geographical zone). In terms of climate, the tropics receive sunlight that is more direct than the rest of Earth and are generally hotter and wetter as they aren't affected as much by the solar seasons. The word "tropical" sometimes refers to this sort of climate in the zone rather than to the geographical zone itself. The tropical zone includes deserts and snow-capped mountains, which are not tropical in the climatic sense. The tropics are distinguished from the other climatic and biomatic regions of Earth, which are the middle latitudes and the polar regions on either side of the equatorial zone. The tropics constitute 40% of Earth's surface area and contain 36% of Earth's landmass. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floodplain
A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudie, A. S., 2004, ''Encyclopedia of Geomorphology'', vol. 1. Routledge, New York. The soils usually consist of clays, silts, sands, and gravels deposited during floods. Because the regular flooding of floodplains can deposit nutrients and water, floodplains frequently have high soil fertility; some important agricultural regions, such as the Mississippi river basin and the Nile, rely heavily on the flood plains. Agricultural regions as well as urban areas have developed near or on floodplains to take advantage of the rich soil and fresh water. However, the risk of flooding has led to increasing efforts to control flooding. Formation Most floodplains are formed by deposition on the inside of river meanders and by overbank flow. Wherev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irrigation
Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has been developed by many cultures around the world. Irrigation helps to grow crops, maintain landscapes, and revegetate disturbed soils in dry areas and during times of below-average rainfall. In addition to these uses, irrigation is also employed to protect crops from frost, suppress weed growth in grain fields, and prevent soil consolidation. It is also used to cool livestock, reduce dust, dispose of sewage, and support mining operations. Drainage, which involves the removal of surface and sub-surface water from a given location, is often studied in conjunction with irrigation. There are several methods of irrigation that differ in how water is supplied to plants. Surface irrigation, also known as gravity irrigation, is the oldest form of irr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swamp
A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in creating this environment. Swamps vary in size and are located all around the world. The water of a swamp may be fresh water, brackish water, or seawater. Freshwater swamps form along large rivers or lakes where they are critically dependent upon rainwater and seasonal flooding to maintain natural water level fluctuations.Hughes, F.M.R. (ed.). 2003. The Flooded Forest: Guidance for policy makers and river managers in Europe on the restoration of floodplain forests. FLOBAR2, Department of Geography, University of Cambridge, Cambridge, UK. 96 p. Saltwater swamps are found along tropical and subtropical coastlines. Some swamps have hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodic inu ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
