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Over-exploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term applies to natural resources such as water aquifers, grazing pastures and forests, wild medicinal plants, fish stocks and other wildlife. In ecology, overexploitation describes one of the five main activities threatening global biodiversity. Ecologists use the term to describe populations that are harvested at an unsustainable rate, given their natural rates of mortality and capacities for reproduction. This can result in extinction at the population level and even extinction of whole species. In conservation biology, the term is usually used in the context of human economic activity that involves the taking of biological resources, or organisms, in larger numbers than their populations can withstand. The term is also used and defined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overfishing
Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in the species becoming increasingly underpopulated in that area. Overfishing can occur in water bodies of any sizes, such as ponds, wetlands, rivers, lakes or oceans, and can result in resource depletion, reduced biological growth rates and low biomass levels. Sustained overfishing can lead to critical depensation, where the fish population is no longer able to sustain itself. Some forms of overfishing, such as the overfishing of sharks, has led to the upset of entire marine ecosystems. Types of overfishing include: growth overfishing, recruitment overfishing, ecosystem overfishing. The ability of a fishery to recover from overfishing depends on whether its overall carrying capacity and the variety of ecological conditions are suitable f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mamo
Mamo or woowoo is a common name for two species of extinct birds. Together with the extant ʻIʻiwi they make up the genus ''Drepanis''. These nectarivorous finches were endemic to Hawaii but are now extinct. The Hawaiian name may be related to the name of the ōō ('' Moho nobilis''), a bird with a similar appearance. Another name for the mamo was ''ōō-nuku-umu'', meaning "ōō with the sucking beak". Two species are known. Hawaii mamo The Hawaii mamo (''Drepanis pacifica'') was about in length. Its plumage was glossy black with yellow rumps and thigh feathers and a small yellow shoulder patch. The tail was black and there was a white basal primary patch and white shafts along the primaries. The bill was long, curved and black. Legs were dark gray or black This was a shy species that lived in the forest canopy and fed on the nectar of ''Lobelia'' species that possess curved, tubular flowers. Its call was a long, plaintive whistle. The bright golden-yellow feath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Haasts Eagle Attacking New Zealand Moa
In folklore, giants (from Ancient Greek: '' gigas'', cognate giga-) are beings of human-like appearance, but are at times prodigious in size and strength or bear an otherwise notable appearance. The word ''giant'' is first attested in 1297 from Robert of Gloucester's chronicle. It is derived from the '' Gigantes'' ( grc-gre, Γίγαντες) of Greek mythology. Fairy tales such as ''Jack the Giant Killer'' have formed the modern perception of giants as dimwitted ogres, sometimes said to eat humans, while other giants tend to eat the livestock. The antagonist in ''Jack and the Beanstalk'' is often described as a giant. In some more recent portrayals, like those of Jonathan Swift and Roald Dahl, some giants are both intelligent and friendly. Literary and cultural analysis Giants appear in the folklore of cultures worldwide as they represent a relatively simple concept. Representing the human body enlarged to the point of being monstrous, giants evoke terror and remind humans o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fauna
Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is ''flora'', and for fungi, it is ''funga''. Flora, fauna, funga and other forms of life are collectively referred to as ''Biota (ecology), biota''. Zoologists and paleontologists use ''fauna'' to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess Shale fauna". Paleontology, Paleontologists sometimes refer to a sequence of faunal stages, which is a series of rocks all containing similar fossils. The study of animals of a particular region is called faunistics. Etymology ''Fauna of Madagascar, Fauna'' comes from the name Fauna (deity), Fauna, a Roman goddess of earth and fertility, the Roman god Faunus, and the related forest spirits called Fauns. All three words are cognates of the name of the Greek god Pan (god), Pan, and ''panis'' is the Greek language, Greek equivalent of fauna. ''Fauna'' is also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora
Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms ''gut flora'' or ''skin flora''. Etymology The word "flora" comes from the Latin name of Flora (mythology), Flora, the goddess of plants, flowers, and fertility in Roman mythology. The technical term "flora" is then derived from a metonymy of this goddess at the end of the sixteenth century. It was first used in poetry to denote the natural vegetation of an area, but soon also assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century. The distinction between vegetation (the general appearance of a community) and flora (the taxonomic composition of a community) was first made by Jules Thurmann (1849). Prior to this, the two terms were used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endangered Species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and invasive species. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration. Human activity is a significant cause in causing some species to become endangered. Conservation status The conservation status of a species indicates the likelihood that it will become extinct. Multiple factors are considered when assessing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquifer
An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials ( gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characteristics. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology. Related terms include aquitard, which is a bed of low permeability along an aquifer, and aquiclude (or ''aquifuge''), which is a solid, impermeable area underlying or overlying an aquifer, the pressure of which could create a confined aquifer. The classification of aquifers is as follows: Saturated versus unsaturated; aquifers versus aquitards; confined versus unconfined; isotropic versus anisotropic; porous, karst, or fractured; transboundary aquifer. Challenges for using groundwater include: overdrafting (extracting groundwater beyond the equilibrium yield of the aquifer), groundwater-related subsidence of land, groundwater becoming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overdrafting
Overdrafting is the process of extracting groundwater beyond the equilibrium yield of an aquifer. Groundwater is one of the largest sources of fresh water and is found underground. Groundwater depletion is comparable to a bank account in which more money is withdrawn than deposited. The primary cause of groundwater depletion is the excessive pumping of groundwater up from underground aquifers. There are two sets of yields: safe yield and sustainable yield. Safe yield is the amount of groundwater that can be withdrawn over a period of time without exceeding the long-term recharge rate or affecting the aquifer integrity. Sustainable yield is the amount of water extraction that can be sustained indefinitely without negative hydrological impacts, taking into account both recharge rate and surface water impacts. There are two types of aquifers: confined and unconfined. In confined aquifers, there is an overbearing layer called aquitard, which contains impermeable materials through whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest Management
Forest management is a branch of forestry concerned with overall administrative, legal, economic, and social aspects, as well as scientific and technical aspects, such as silviculture, protection, and forest regulation. This includes management for timber, aesthetics, recreation, urban values, water, wildlife, inland and nearshore fisheries, wood products, plant genetic resources, and other forest resource values. Management objectives can be for conservation, utilisation, or a mixture of the two. Techniques include timber extraction, planting and replanting of different species, building and maintenance of roads and pathways through forests, and preventing fire. Definition The forest is a natural system that can supply different products and services. Forests supply water, mitigate climate change, provide habitats for wildlife including many pollinators which are essential for sustainable food production, provide timber and fuelwood, serve as a source of non-wood forest produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overlogging
Overlogging is a form of overexploitation caused by legal or illegal logging activities that lead to unsustainable or irrecoverable deforestation and permanent habitat destruction for forest wildlife. Causes The use of poor logging practices and heavy machinery leads to overlogged forests. Norman Myers argued that forms of environmental degradation like overlogging are a consequence of " perverse subsidies." The production of disposable tissues significantly contributes to the effects of overlogging. In rural China, overlogging is related to the need for firewood as fuel. Overlogging is often associated with attempts at reducing the " Third world debt," although it is not restricted to developing countries. Effects With the developed world's growing demand for pulp and paper, overlogging is an imminent threat to Earth's forests. In central Japan, forests located closer to power plants were found to be more vulnerable to overlogging. Overlogging has caused significant da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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