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No-analog (ecology)
In paleoecology and ecological forecasting, a no-analog community or climate is one that is compositionally different from a (typically modern) baseline for measurement. Alternative naming conventions to describe no-analog communities and climates may include novel, emerging, mosaic, disharmonious and intermingled. Modern climates, communities and ecosystems are often studied in an attempt to understand no-analogs that have happened in the past and those that may occur in the future. This use of a modern analog to study the past draws on the concept of uniformitarianism. Along with the use of these modern analogs, actualistic studies and taphonomy are additional tools that are used in understanding no-analogs. Statistical tools are also used to identify no-analogs and their baselines, often through the use of dissimilarity analyses or analog matching Study of no-analog fossil remains are often carefully evaluated as to rule out mixing of fossils in an assemblage due to erosion, ani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleoecology
Paleoecology (also spelled palaeoecology) is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs a variety of fields including paleontology, ecology, climatology and biology. Paleoecology emerged from the field of paleontology in the 1950s, though paleontologists have conducted paleoecological studies since the creation of paleontology in the 1700s and 1800s. Combining the investigative approach of searching for fossils with the theoretical approach of Charles Darwin and Alexander von Humboldt, paleoecology began as paleontologists began examining both the ancient organisms they discovered and the reconstructed environments in which they lived. Visual depictions of past marine and terrestrial communities have been considered an early form of paleoecology. Overview of paleoecological approaches * Classic paleoecology uses data from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusca
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gastropod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Distribution
Species distribution —or species dispersion — is the manner in which a biological taxon is spatially arranged. The geographic limits of a particular taxon's distribution is its range, often represented as shaded areas on a map. Patterns of distribution change depending on the scale at which they are viewed, from the arrangement of individuals within a small family unit, to patterns within a population, or the distribution of the entire species as a whole (range). Species distribution is not to be confused with dispersal, which is the movement of individuals away from their region of origin or from a population center of high density. Range In biology, the range of a species is the geographical area within which that species can be found. Within that range, distribution is the general structure of the species population, while dispersion is the variation in its population density. Range is often described with the following qualities: * Sometimes a distinction is made betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megafauna
In terrestrial zoology, the megafauna (from Greek μέγας ''megas'' "large" and New Latin ''fauna'' "animal life") comprises the large or giant animals of an area, habitat, or geological period, extinct and/or extant. The most common thresholds used are weight over see page 17 (i.e., having a mass comparable to or larger than a human) or over a tonne, (i.e., having a mass comparable to or larger than an ox). The first of these include many species not popularly thought of as overly large, and being the only few large animals left in a given range/area, such as white-tailed deer, Thomson's gazelle, and red kangaroo. In practice, the most common usage encountered in academic and popular writing describes land mammals roughly larger than a human that are not (solely) domesticated. The term is especially associated with the Pleistocene megafauna – the land animals often larger than their extant counterparts that are considered archetypical of the last ice age, such as mammoth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Regime
A fire regime is the pattern, frequency, and intensity of the bushfires and wildfires that prevail in an area over long periods of time. It is an integral part of fire ecology, and renewal for certain types of ecosystems. A fire regime describes the spatial and temporal patterns and ecosystem impacts of fire on the landscape, and provides an integrative approach to identifying the impacts of fire at an ecosystem or landscape level.Morgan, Penelope; Hardy; Swetnam; Rollins; Long (1999)"Mapping fire regimes across time and space: Understanding coarse and fine-scale fire patterns"(PDF). ''International Journal of Wildland Fire''. 10: 329–342 – via Google Scholar. If fires are too frequent, plants may be killed before they have matured, or before they have set sufficient seed to ensure population recovery. If fires are too infrequent, plants may mature, senesce, and die without ever releasing their seed. Fire regimes can change with the spatial and temporal variations in topography, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.Oxford University Press – Why Geography Matters: More Than Ever (book) – "Holocene Humanity" section https://books.google.com/books?id=7P0_sWIcBNsC The Holocene corresponds with the rapid proliferation, growth and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larch
Larches are deciduous conifers in the genus ''Larix'', of the family Pinaceae (subfamily Laricoideae). Growing from tall, they are native to much of the cooler temperate northern hemisphere, on lowlands in the north and high on mountains further south. Larches are among the dominant plants in the boreal forests of Siberia and Canada. Although they are conifers, larches are deciduous trees that lose their needles in the autumn. Etymology The English name Larch ultimately derives from the Latin "larigna," named after the ancient settlement of Larignum. The story of its naming was preserved by Vitruvius: It is worth while to know how this wood was discovered. The divine Caesar, being with his army in the neighbourhood of the Alps, and having ordered the towns to furnish supplies, the inhabitants of a fortified stronghold there, called Larignum, trusting in the natural strength of their defences, refused to obey his command. So the general ordered his forces to the assault. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ostrya
''Ostrya'' is a genus of eight to 10 small deciduous trees belonging to the birch family Betulaceae. Common names include hop-hornbeam and hophornbeam. It may also be called ironwood, a name shared with a number of other plants. The genus is native in southern Europe, southwest and eastern Asia, and North and Central America. They have a conical or irregular crown and a scaly, rough bark. They have alternate and double-toothed birch-like leaves 3–10 cm long. The flowers are produced in spring, with male catkins 5–10 cm long and female aments 2–5 cm long. The fruit form in pendulous clusters 3–8 cm long with 6–20 seeds; each seed is a small nut 2–4 mm long, fully enclosed in a bladder-like involucre. The wood is very hard and heavy. The genus name ''Ostrya'' is derived from the Greek word (), which may be related to () "shell (of an animal)". Regarded as a weed tree by some foresters, this hard and stable wood was historically used to fashion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pine
A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts 187 species names of pines as current, together with more synonyms. The American Conifer Society (ACS) and the Royal Horticultural Society accept 121 species. Pines are commonly found in the Northern Hemisphere. ''Pine'' may also refer to the lumber derived from pine trees; it is one of the more extensively used types of lumber. The pine family is the largest conifer family and there are currently 818 named cultivars (or trinomials) recognized by the ACS. Description Pine trees are evergreen, coniferous resinous trees (or, rarely, shrubs) growing tall, with the majority of species reaching tall. The smallest are Siberian dwarf pine and Potosi pinyon, and the tallest is an tall ponderosa pine located in southern Oregon's Rogue Riv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spruce
A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfamily Piceoideae. Spruces are large trees, from about 20 to 60 m (about 60–200 ft) tall when mature, and have whorled branches and conical form. They can be distinguished from other members of the pine family by their needles (leaves), which are four-sided and attached singly to small persistent peg-like structures (pulvini or sterigmata) on the branches, and by their cones (without any protruding bracts), which hang downwards after they are pollinated. The needles are shed when 4–10 years old, leaving the branches rough with the retained pegs. In other similar genera, the branches are fairly smooth. Spruce are used as food plants by the larvae of some Lepidoptera (moth and butterfly) species, such as the eastern spruce budwo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fraxinus
''Fraxinus'' (), common name, commonly called ash, is a genus of flowering plants in the olive and lilac family, Oleaceae. It contains 45–65 species of usually medium to large trees, mostly deciduous, though a number of Subtropics, subtropical species are evergreen. The genus is widespread across much of Europe, Asia, and North America. The leaf, leaves are opposite leaves, opposite (rarely in Whorl (botany), whorls of three), and mostly pinnate, pinnately compound, though simple in a few species. The seeds, popularly known as "keys" or "helicopter seeds", are a type of fruit known as a samara (fruit), samara. Some ''Fraxinus'' species are Dioecy, dioecious, having male and female flowers on separate plants but sex in ash is expressed as a continuum between male and female individuals, dominated by unisexual trees. With age, ash may change their sexual function from predominantly male and hermaphrodite towards femaleness ; if grown as an ornamental and both sexes are present, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allopatric Speciation
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow. Various geographic changes can arise such as the movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations. These factors can substantially alter a region's geography, resulting in the separation of a species population into isolated subpopulations. The vicariant populations then undergo genetic changes as they become subjected to different selective pressures, experience genetic drift, and accumulate different mutations in the separated populations' gene pools. The barriers prevent the exchange of genetic information betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
