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Grasslands
A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceous plant, herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on Earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area. Definitions Included among the variety of definitions for grasslands are: * "...any plant community, including harvested forages, in which grasses and/or legumes make up the dominant vegetation." * "...terrestrial ecosystems dominated by herbaceous and shrub vegetation, and maintained by fire, grazing, drought and/or freezing temperatures." (Pilot Assessm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biodiversity & Ecology
Biodiversity is the variability of life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and phylogenetic diversity. Diversity is not distributed evenly on Earth. It is greater in the tropics as a result of the warm climate and high primary productivity in the region near the equator. Tropical forest ecosystems cover less than one-fifth of Earth's terrestrial area and contain about 50% of the world's species. There are latitudinal gradients in species diversity for both marine and terrestrial taxa. Since life began on Earth, six major mass extinctions and several minor events have led to large and sudden drops in biodiversity. The Phanerozoic aeon (the last 540 million years) marked a rapid growth in biodiversity via the Cambrian explosion. In this period, the majority of multicellular phyla first appeared. The next 400 million years included repeated, massive biodiversity losses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western United States
The Western United States (also called the American West, the Western States, the Far West, the Western territories, and the West) is List of regions of the United States, census regions United States Census Bureau. As American settlement in the U.S. Manifest destiny, expanded westward, the meaning of the term ''the West'' changed. Before around 1800, the crest of the Appalachian Mountains was seen as the American frontier, western frontier. The frontier moved westward and eventually the lands west of the Mississippi River were considered ''the West''. The U.S. Census Bureau's definition of the 13 westernmost states includes the Rocky Mountains and the Great Basin to the West Coast of the United States, Pacific Coast, and the mid-Pacific islands state, Hawaii. To the east of the Western United States is the Midwestern United States and the Southern United States, with Canada to the north and Mexico to the south. The West contains several major biomes, including arid and Sem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bamboo
Bamboos are a diverse group of mostly evergreen perennial plant, perennial flowering plants making up the subfamily (biology), subfamily Bambusoideae of the grass family Poaceae. Giant bamboos are the largest members of the grass family, in the case of ''Dendrocalamus sinicus'' having individual stalks (Culm (botany), culms) reaching a length of , up to in thickness and a weight of up to . The internodes of bamboos can also be of great length. ''Kinabaluchloa, Kinabaluchloa wrayi'' has internodes up to in length. and ''Arthrostylidium schomburgkii'' has internodes up to in length, exceeded in length only by Cyperus papyrus, papyrus. By contrast, the stalks of the tiny bamboo Raddiella, ''Raddiella vanessiae'' of the savannas of French Guiana measure only in length by about in width. The origin of the word "bamboo" is uncertain, but it most likely comes from the Dutch language, Dutch or Portuguese language, Portuguese language, which originally borrowed it from Malay langua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rice
Rice is a cereal grain and in its Domestication, domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species ''Oryza sativa'' (Asian rice)—or, much less commonly, ''Oryza glaberrima'' (African rice). Asian rice was domesticated in China some 13,500 to 8,200 years ago; African rice was domesticated in Africa about 3,000 years ago. Rice has become commonplace in many cultures worldwide; in 2023, 800 million tons were produced, placing it third after sugarcane and maize. Only some 8% of rice is traded internationally. China, India, and Indonesia are the largest consumers of rice. A substantial amount of the rice produced in developing nations is lost after harvest through factors such as poor transport and storage. Rice yields can be reduced by pests including insects, rodents, and birds, as well as by weeds, and by List of rice diseases, diseases such as rice blast. Traditional rice polyc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytolith
Phytoliths (from Greek language, Greek, "plant stone") are rigid, microscopic mineral deposits found in some plant tissues, often persisting after the decay of the plant. Although some use "phytolith" to refer to all mineral secretions by plants, it more commonly refers to Silicon dioxide, siliceous plant remains. Phytoliths come in varying shapes and sizes. The plants which exhibit them take up dissolved silica from the groundwater, whereupon it is deposited within different intracellular and extracellular structures of the plant.Piperno, Dolores R. (2006). Phytoliths: A Comprehensive Guide for Archaeologists and Paleoecologists. AltaMira Press . The silica is absorbed in the form of orthosilicic acid, monosilicic acid (Si(OH)4), and is carried by the plant's Circulatory system, vascular system to the cell walls, cell lumen, and intercellular spaces. Depending on the plant Taxon, taxa and soil condition, absorbed silica can range from 0.1% to 10% of the plant's total dry weight ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutionary history, evolution of dinosaurs is a subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, Evolution of birds, having evolved from earlier Theropoda, theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomy (biology), taxonomic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coprolite
A coprolite (also known as a coprolith) is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name is derived from the Greek words κόπρος (''kopros'', meaning "dung") and λίθος (''lithos'', meaning "stone"). They were first described by William Buckland in 1829. Before this, they were known as "fossil fir cones" and "bezoar stones". They serve a valuable purpose in paleontology because they provide direct evidence of the predation and diet of extinct organisms. Coprolites may range in size from a few millimetres to over 60 centimetres. Coprolites, distinct from '' paleofeces'', are fossilized animal dung. Like other fossils, coprolites have had much of their original composition replaced by mineral deposits such as silicates and calcium carbonates. Paleofeces, on the other hand, retain much of their original organic compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geological period of the entire Phanerozoic. The name is derived from the Latin , 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation . The Cretaceous was a period with a relatively warm climate, resulting in high Sea level#Local and eustatic, eustatic sea levels that created numerous shallow Inland sea (geology), inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to the poles. Many of the dominant taxonomic gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organism
An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have been proposed to define what an organism is. Among the most common is that an organism has autonomous reproduction, Cell growth, growth, and metabolism. This would exclude viruses, despite the fact that they evolution, evolve like organisms. Other problematic cases include colonial organisms; a colony of eusocial insects is organised adaptively, and has Germ-Soma Differentiation, germ-soma specialisation, with some insects reproducing, others not, like cells in an animal's body. The body of a siphonophore, a jelly-like marine animal, is composed of organism-like zooids, but the whole structure looks and functions much like an animal such as a jellyfish, the parts collaborating to provide the functions of the colonial organism. The evolutiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graminoid
In botany and ecology, a graminoid refers to a herbaceous plant with a grass-like morphology, i.e., elongated culms with long, blade-like leaves. They are contrasted with forbs, herbaceous plants without grass-like features. The plants most often referred to include the families Poaceae (grasses in the strict sense), Cyperaceae (sedges), and Juncaceae (rushes). These are not closely related but belong to different clades in the order Poales. The grasses (Poaceae) are by far the largest family, with some 12,000 species. Ecology Besides their similar morphology, graminoids share a widespread occurrence and often dominance in open habitats such as grasslands or marshes. They can, however, also be found in the understory of forests. Sedges and rushes tend to prefer wetter habitats than grasses. Gallery File:Pitrus (Juncus effusus) 05.JPG, alt=Common rush in shallow water, Common rush ('' Juncus effusus''), Juncaceae File:Cyperus capitatus 01.jpg, alt=Nutsedge on dune, Nutse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meadow
A meadow ( ) is an open habitat or field, vegetated by grasses, herbs, and other non- woody plants. Trees or shrubs may sparsely populate meadows, as long as they maintain an open character. Meadows can occur naturally under favourable conditions but are often artificially created from cleared shrub or woodland for the production of hay, fodder or livestock. Meadow habitats as a group are characterized as semi-natural grasslands, meaning that they are largely composed of species native to the region, with only limited human intervention. Meadows attract a multitude of wildlife and support flora and fauna that could not thrive in other habitats. They are ecologically important since they provide areas for animal courtship displays, nesting, food gathering, pollinating insects, and sometimes sheltering if the vegetation is high enough. Intensified agricultural practices (too frequent mowing, use of mineral fertilizers, manure and insecticides) may lead to declin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
