Owens pupfish
The Owens pupfish is a rare species of fish in the family Cyprinodontidae, the pupfish. It is endemic to California in the United States, it is a federally listed endangered species of the United States. This pupfish is up to 5 centimetres long, the largest males sometimes longer; the male is blue-gray. The female is greenish brown with a whitish belly; the pupfish tolerates a wide range of water conditions. Its native habitat includes desert marshes with water temperatures up to 33 °C in the summer and layers of ice during the winter; the water in some areas has four times the salt content of the ocean, as well as low oxygen. This fish was once common in the Owens Valley of California, occurring in most water bodies between Fish Slough and Lone Pine, which are 70 miles apart, it occurred in associated sloughs and marshes. At that time the Paiute people dried them for the winter; the diversion of water from the Owens River to the Los Angeles Metropolitan Area during the California Water Wars eliminated most of the water bodies that were the pupfish's habitat.
Predation by introduced species of fish may have decimated remaining populations. By 1942 this pupfish was believed to be extinct, it was rediscovered in 1964. When they were transferred to a safer location, the entire global population of this pupfish was contained in two buckets; the California Department of Fish and Game established six populations in managed refuge using these fish. Four of these populations remain today. Threats to the four populations include the encroachment of cattails into the waterways; the plant clogs the habitat and collects detritus, which eliminates the pupfish's breeding substrates. The CDFG tends the four populations. Introduced species of aquatic organisms pose a threat, they include predatory fish such as largemouth bass, smallmouth bass, brown trout, bluegill, as well as crayfish and bullfrogs. The severe reduction of the species into a single small population may have created a genetic bottleneck. Other local Cyprinodon include Death Valley pupfish, Shoshone pupfish, the extinct Tecopa pupfish, Devils Hole pupfish, the desert pupfish.
Gimenez Dixon, M. 1996. Cyprinodon radiosus. 2011 IUCN Red List of Threatened Species. Downloaded on 28 September 2011. Terrill, C. Pister's Pupfish myurbanwild.com
Death Valley
Death Valley is a desert valley located in Eastern California, in the northern Mojave Desert bordering the Great Basin Desert. It is one of the hottest places in the world along with deserts in the Middle East. Death Valley's Badwater Basin is the point of the lowest elevation in North America, at 282 feet below sea level; this point is 84.6 miles east-southeast of Mount Whitney, the highest point in the contiguous United States, with an elevation of 14,505 feet. On the afternoon of July 10, 1913, the United States Weather Bureau recorded a high temperature of 134 °F at Furnace Creek in Death Valley; this temperature stands as the highest ambient air temperature recorded at the surface of the Earth. Located near the border of California and Nevada, in the Great Basin, east of the Sierra Nevada mountains, Death Valley constitutes much of Death Valley National Park and is the principal feature of the Mojave and Colorado Deserts Biosphere Reserve, it is located in Inyo County, California. It runs from north to south between the Amargosa Range on the east and the Panamint Range on the west.
It has an area of about 3,000 sq mi. The highest point in Death Valley itself is Telescope Peak in the Panamint Range, which has an elevation of 11,043 feet. Death Valley is an excellent example of a graben, or a downdropped block of land between two mountain ranges, it lies at the southern end of a geological trough known as Walker Lane. The valley is bisected by a right lateral strike slip fault system, represented by the Death Valley Fault and the Furnace Creek Fault; the eastern end of the left lateral Garlock Fault intersects the Death Valley Fault. Furnace Creek and the Amargosa River flow through the valley but disappear into the sands of the valley floor. Death Valley contains salt pans. According to current geological consensus, at various times during the middle of the Pleistocene era, which ended 10,000–12,000 years ago, an inland lake referred to as Lake Manly formed in Death Valley. Lake Manly was nearly 100 miles long and 600 feet deep, the end-basin in a chain of lakes that began with Mono Lake in the north and continued through multiple basins down the Owens River Valley through Searles and China Lakes and the Panamint Valley to the immediate west.
As the area turned to desert, the water evaporated, leaving the abundance of evaporitic salts such as common sodium salts and borax, which were exploited during the modern history of the region 1883 to 1907. Death Valley has a subtropical, hot desert climate, with long hot summers and short, mild winters, as well as little rainfall; as a general rule, lower altitudes tend to have higher temperatures. When the sun heats the ground, that heat is radiated upward, but the dense below-sea-level air absorbs some of this radiation and radiates some of it back towards the ground. In addition, the high valley walls trap rising hot air and recycle it back down to the valley floor, where it is heated by compression; this process is important in Death Valley, as it provides its specific climate and geography. The valley is surrounded by mountains, while its surface is flat and devoid of plants, so much of the sun's heat can reach the ground, absorbed by soil and rock; when air at ground level is heated, it begins to rise, moving up past steep, high mountain ranges, which cools sinking back down towards the valley more compressed.
This air is reheated by the sun to a higher temperature, moving up the mountain again, whereby the air moves up and down in a circular motion in cycles, similar to how a convection oven works. This heated air increases ground temperature markedly, forming the hot wind currents that are trapped by atmospheric pressure and mountains and thus stay within the valley; such hot wind currents contribute to perpetual drought-like conditions in Death Valley and prevent much cloud formation from passing through the confines of the valley, where precipitation is in the form of a virga. Death Valley holds temperature records because it has an unusually high number of factors that lead to high atmospheric temperatures; the depth and shape of Death Valley influence its summer temperatures. The valley is a long, narrow basin 282 feet below sea level, yet is walled by high, steep mountain ranges; the clear, dry air and sparse plant cover allow sunlight to heat the desert surface. Summer nights provide little relief.
Moving masses of super-heated air blow through the valley creating high temperatures. The hottest air temperature recorded in Death Valley was 134 °F on July 10, 1913, at Greenland Ranch, the highest atmospheric temperature recorded on earth. A report of a temperature of 58 °C recorded in Libya in 1922 was determined to be inaccurate. During the heat wave that peaked with that record, five consecutive days reached 129 above; some meteorologists dispute the accuracy of the 1913 temperature measurement. The highest surface temperature recorded in Death Valley was 201.0 °F on July 15, 1972, at Furnace Creek, the highest ground surface temperature recorded on earth, as well as the only recorded surface temperature of above 200 °F. The greatest number of consecutive days with a maximum temperature of 100 °F or above was 154 days in the summer of 2001; the summer of 1996 had 40 days over 120 °F, 105 days over 110 °F. The summer of 1917 had 52 days where the temperature
Saratoga Springs pupfish
The Saratoga Springs pupfish is a subspecies of the Amargosa pupfish of the family Cyprinodontidae. The native population is endemic to Saratoga Springs, a small wetland in Death Valley National Park in the United States; the pupfish is a member of the genus Cyprinodon. Most divergence of Cyprinodon species took place during the early-to-mid Pleistocene, a time when pluvial lakes intermittently filled the now-desert region, though some may have occurred during the last 10,000 years; the evaporation of the lakes resulted in the geographic isolation of small Cyprinodon populations and the speciation of C. nevadensis. Ichthyologists Rosa Smith Eigenmann and Carl H. Eigenmann first identified Cyprinodon nevadensis in 1889. Authors considered it the same species as Cyprinodon macularius. In the 1940s, Robert Rush Miller again described C. nevadensis as a distinct species, identified six subspecies, including C. n. nevadensis. Other subspecies include the Amargosa River pupfish, the Ash Meadows pupfish, the Warm Springs pupfish, the Shoshone pupfish, the extinct Tecopa pupfish.
Male Saratoga Springs pupfish are bright blue in color. The fish have a standard length of 4 cm, the total length is greater than 5 cm; the diet of C. n. nevadensis is typical of pupfishes. Cyanobacteria are the primary food source, for which their lengthy guts are well adapted. Ostracods and the larvae of chironomids provide seasonal nutrition. Mating behavior is similar to other spring-dwellers. Males defend territories. While the fish are capable of surviving a wide range of temperatures, reproduction is limited to a narrower range; the fish is only known to occur at Saratoga Springs. A 30-foot diameter, 3–6 feet deep spring pool overflows into several ponds totaling about 4–6 acres; the temperature at the spring is a near constant 82–84 degrees Fahrenheit, while the ponds fluctuate seasonally between 50 and 120 degrees Fahrenheit. Fish at all life stages are found in the ponds, but juvenile fish are not known to occur in the spring itself. A population was introduced at Lake Tuendae, an artificial pond in Zzyzx, but reports conflict as to its continued survival there.
The Saratoga Springs pupfish carries no official conservation status. The state of California has identified it as qualifying as threatened based on its limited distribution and the possibility that distant groundwater pumping may deplete the aquifer that supplies Saratoga Springs; the aquifer may extend to as far away as western Utah. Groundwater depletion in the Las Vegas Valley, 75 miles to the northeast, is of particular concern. In order to protect the pupfish and several other sensitive species, the National Park Service prohibits visitors from entering the wetland at Saratoga Springs. Death Valley geology field trip: Saratoga and Valley Springs
Ice age
An ice age is a long period of reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth is in the Quaternary glaciation, known in popular terminology as the Ice Age. Individual pulses of cold climate are termed "glacial periods", intermittent warm periods are called "interglacials", with both climatic pulses part of the Quaternary or other periods in Earth's history. In the terminology of glaciology, ice age implies the presence of extensive ice sheets in both northern and southern hemispheres. By this definition, we are in an interglacial period—the Holocene; the amount of heat trapping gases emitted into Earth's Oceans and atmosphere will prevent the next ice age, which otherwise would begin in around 50,000 years, more glacial cycles. In 1742, Pierre Martel, an engineer and geographer living in Geneva, visited the valley of Chamonix in the Alps of Savoy. Two years he published an account of his journey.
He reported that the inhabitants of that valley attributed the dispersal of erratic boulders to the glaciers, saying that they had once extended much farther. Similar explanations were reported from other regions of the Alps. In 1815 the carpenter and chamois hunter Jean-Pierre Perraudin explained erratic boulders in the Val de Bagnes in the Swiss canton of Valais as being due to glaciers extending further. An unknown woodcutter from Meiringen in the Bernese Oberland advocated a similar idea in a discussion with the Swiss-German geologist Jean de Charpentier in 1834. Comparable explanations are known from the Val de Ferret in the Valais and the Seeland in western Switzerland and in Goethe's scientific work; such explanations could be found in other parts of the world. When the Bavarian naturalist Ernst von Bibra visited the Chilean Andes in 1849–1850, the natives attributed fossil moraines to the former action of glaciers. Meanwhile, European scholars had begun to wonder. From the middle of the 18th century, some discussed ice as a means of transport.
The Swedish mining expert Daniel Tilas was, in 1742, the first person to suggest drifting sea ice in order to explain the presence of erratic boulders in the Scandinavian and Baltic regions. In 1795, the Scottish philosopher and gentleman naturalist, James Hutton, explained erratic boulders in the Alps by the action of glaciers. Two decades in 1818, the Swedish botanist Göran Wahlenberg published his theory of a glaciation of the Scandinavian peninsula, he regarded glaciation as a regional phenomenon. Only a few years the Danish-Norwegian geologist Jens Esmark argued a sequence of worldwide ice ages. In a paper published in 1824, Esmark proposed changes in climate as the cause of those glaciations, he attempted to show. During the following years, Esmark's ideas were discussed and taken over in parts by Swedish and German scientists. At the University of Edinburgh Robert Jameson seemed to be open to Esmark's ideas, as reviewed by Norwegian professor of glaciology Bjørn G. Andersen. Jameson's remarks about ancient glaciers in Scotland were most prompted by Esmark.
In Germany, Albrecht Reinhard Bernhardi, a geologist and professor of forestry at an academy in Dreissigacker, since incorporated in the southern Thuringian city of Meiningen, adopted Esmark's theory. In a paper published in 1832, Bernhardi speculated about former polar ice caps reaching as far as the temperate zones of the globe. In 1829, independently of these debates, the Swiss civil engineer Ignaz Venetz explained the dispersal of erratic boulders in the Alps, the nearby Jura Mountains, the North German Plain as being due to huge glaciers; when he read his paper before the Schweizerische Naturforschende Gesellschaft, most scientists remained sceptical. Venetz convinced his friend Jean de Charpentier. De Charpentier transformed Venetz's idea into a theory with a glaciation limited to the Alps, his thoughts resembled Wahlenberg's theory. In fact, both men shared the same volcanistic, or in de Charpentier's case rather plutonistic assumptions, about the Earth's history. In 1834, de Charpentier presented his paper before the Schweizerische Naturforschende Gesellschaft.
In the meantime, the German botanist Karl Friedrich Schimper was studying mosses which were growing on erratic boulders in the alpine upland of Bavaria. He began to wonder. During the summer of 1835 he made some excursions to the Bavarian Alps. Schimper came to the conclusion that ice must have been the means of transport for the boulders in the alpine upland. In the winter of 1835 to 1836 he held. Schimper assumed that there must have been global times of obliteration with a cold climate and frozen water. Schimper spent the summer months of 1836 at Devens, near Bex, in the Swiss Alps with his former university friend Louis Agassiz and Jean de Charpentier. Schimper, de Charpentier and Venetz convinced Agassiz that there had been a time of glaciation. During the winter of 1836/37, Agassiz and Schimper developed the theory of a sequence of glaciations, they drew upon the preceding works of Venetz, de Charpentier and on their own fieldwork. Agassiz appears to have been familiar with Bernhardi's paper at that time.
At the beginning of 1837, Schimper coined the term "ice age" for the period of the glaciers. In July 1837 Ag
Integrated Taxonomic Information System
The Integrated Taxonomic Information System is an American partnership of federal agencies designed to provide consistent and reliable information on the taxonomy of biological species. ITIS was formed in 1996 as an interagency group within the US federal government, involving several US federal agencies, has now become an international body, with Canadian and Mexican government agencies participating; the database draws from a large community of taxonomic experts. Primary content staff are housed at the Smithsonian National Museum of Natural History and IT services are provided by a US Geological Survey facility in Denver; the primary focus of ITIS is North American species, but many biological groups exist worldwide and ITIS collaborates with other agencies to increase its global coverage. ITIS provides an automated reference database of common names for species; as of May 2016, it contains over 839,000 scientific names and common names for terrestrial and freshwater taxa from all biological kingdoms.
While the system does focus on North American species at minimum, it includes many species not found in North America among birds, amphibians, bacteria, many reptiles, several plant groups, many invertebrate animal groups. Data presented in ITIS are considered public information, may be distributed and copied, though appropriate citation is requested. ITIS is used as the de facto source of taxonomic data in biodiversity informatics projects. ITIS couples each scientific name with a stable and unique taxonomic serial number as the "common denominator" for accessing information on such issues as invasive species, declining amphibians, migratory birds, fishery stocks, agricultural pests, emerging diseases, it presents the names in a standard classification that contains author, date and bibliographic information related to the names. In addition, common names are available through ITIS in the major official languages of the Americas. ITIS and its international partner, Species 2000, cooperate to annually produce the Catalogue of Life, a checklist and index of the world's species.
The Catalogue of Life's goal was to complete the global checklist of 1.9 million species by 2011. As of May 2012, the Catalogue of Life has reached 1.4 million species—a major milestone in its quest to complete the first up-to-date comprehensive catalogue of all living organisms. ITIS and the Catalogue of Life are core to the Encyclopedia of Life initiative announced May 2007. EOL will be built on various Creative Commons licenses. Of the ~714,000 scientific names in the current database 210,000 were inherited from the database maintained by the National Oceanographic Data Center of the US National Oceanic and Atmospheric Administration; the newer material has been checked to higher standards of taxonomic credibility, over half of the original material has been checked and improved to the same standard. Biological taxonomy is not fixed, opinions about the correct status of taxa at all levels, their correct placement, are revised as a result of new research. Many aspects of classification remain a matter of scientific judgment.
The ITIS database is updated to take account of new research. Records within ITIS include information about how far it has been possible to verify them, its information should be checked against other sources where these are available, against the primary research scientific literature where possible. Agriculture and Agri-Food Canada Comisión Nacional para el Conocimiento y Uso de la Biodiversidad National Oceanic and Atmospheric Administration National Park Service NatureServe Smithsonian Institution United States Department of Agriculture United States Environmental Protection Agency United States Geological Survey United States Fish and Wildlife Service Encyclopedia of Life PlantList Wikispecies World Register of Marine Species Integrated Taxonomic Information System Canada Interface: Integrated Taxonomic Information System Mexico Interface: Sistema Integrado de Información Taxonómica Brasil Interface: Sistema Integrado de Informação Taxonômica –
Mineral
A mineral is, broadly speaking, a solid chemical compound that occurs in pure form. A rock may consist of a single mineral, or may be an aggregate of two or more different minerals, spacially segregated into distinct phases. Compounds that occur only in living beings are excluded, but some minerals are biogenic and/or are organic compounds in the sense of chemistry. Moreover, living beings synthesize inorganic minerals that occur in rocks. In geology and mineralogy, the term "mineral" is reserved for mineral species: crystalline compounds with a well-defined chemical composition and a specific crystal structure. Minerals without a definite crystalline structure, such as opal or obsidian, are more properly called mineraloids. If a chemical compound may occur with different crystal structures, each structure is considered different mineral species. Thus, for example and stishovite are two different minerals consisting of the same compound, silicon dioxide; the International Mineralogical Association is the world's premier standard body for the definition and nomenclature of mineral species.
As of November 2018, the IMA recognizes 5,413 official mineral species. Out of more than 5,500 proposed or traditional ones; the chemical composition of a named mineral species may vary somewhat by the inclusion of small amounts of impurities. Specific varieties of a species sometimes have official names of their own. For example, amethyst is a purple variety of the mineral species quartz; some mineral species can have variable proportions of two or more chemical elements that occupy equivalent positions in the mineral's structure. Sometimes a mineral with variable composition is split into separate species, more or less arbitrarily, forming a mineral group. Besides the essential chemical composition and crystal structure, the description of a mineral species includes its common physical properties such as habit, lustre, colour, tenacity, fracture, specific gravity, fluorescence, radioactivity, as well as its taste or smell and its reaction to acid. Minerals are classified by key chemical constituents.
Silicate minerals comprise 90% of the Earth's crust. Other important mineral groups include the native elements, oxides, carbonates and phosphates. One definition of a mineral encompasses the following criteria: Formed by a natural process. Stable or metastable at room temperature. In the simplest sense, this means. Classical examples of exceptions to this rule include native mercury, which crystallizes at −39 °C, water ice, solid only below 0 °C. Modern advances have included extensive study of liquid crystals, which extensively involve mineralogy. Represented by a chemical formula. Minerals are chemical compounds, as such they can be described by fixed or a variable formula. Many mineral groups and species are composed of a solid solution. For example, the olivine group is described by the variable formula 2SiO4, a solid solution of two end-member species, magnesium-rich forsterite and iron-rich fayalite, which are described by a fixed chemical formula. Mineral species themselves could have a variable composition, such as the sulfide mackinawite, 9S8, a ferrous sulfide, but has a significant nickel impurity, reflected in its formula.
Ordered atomic arrangement. This means crystalline. An ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form and cleavage. There have been several recent proposals to classify amorphous substances as minerals; the formal definition of a mineral approved by the IMA in 1995: "A mineral is an element or chemical compound, crystalline and, formed as a result of geological processes." Abiogenic. Biogenic substances are explicitly excluded by the IMA: "Biogenic substances are chemical compounds produced by biological processes without a geological component and are not regarded as minerals. However, if geological processes were involved in the genesis of the compound the product can be accepted as a mineral."The first three general characteristics are less debated than the last two. Mineral classification schemes and their definitions are evolving to match recent advances in mineral science. Recent changes have included the addition of an organic class, in both the new Dana and the Strunz classification schemes.
The organic class includes a rare group of minerals with hydrocarbons. The IMA Commission on New Minerals and Mineral Names adopted in 2009 a hierarchical scheme for the naming and classification of mineral groups and group names and established seven commissions and four working groups to review and classify minerals into an official listing of their published names. According to these new r
Flora
Flora is the plant life occurring in a particular region or time the occurring or indigenous—native plant life. The corresponding term for animal life is fauna. Flora and other forms of life such as fungi are collectively referred to as biota. Sometimes bacteria and fungi are referred to as flora, as in the terms gut flora or skin flora; the word "flora" comes from the Latin name of Flora, the goddess of plants and fertility in Roman mythology. The technical term "flora" is 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 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 and flora was first made by Jules Thurmann. Prior to this, the two terms were used indiscriminately. Plants are grouped into floras based on region, special environment, or climate.
Regions can be distinct habitats like mountain vs. flatland. Floras can mean plant life of a historic era as in fossil flora. Lastly, floras may be subdivided by special environments: Native flora; the native and indigenous flora of an area. Agricultural and horticultural flora; the plants that are deliberately grown by humans. Weed flora. Traditionally this classification was applied to plants regarded as undesirable, studied in efforts to control or eradicate them. Today the designation is less used as a classification of plant life, since it includes three different types of plants: weedy species, invasive species, native and introduced non-weedy species that are agriculturally undesirable. Many native plants considered weeds have been shown to be beneficial or necessary to various ecosystems; the flora of a particular area or time period can be documented in a publication known as a "flora". Floras may require specialist botanical knowledge to use with any effectiveness. Traditionally they are books.
Simon Paulli's Flora Danica of 1648 is the first book titled "Flora" to refer to the plant world of a certain region. It describes medicinal plants growing in Denmark; the Flora Sinensis by the Polish Jesuit Michał Boym is another early example of a book titled "Flora". However, despite its title it covered not only plants, but some animals of the region, China and India. A published flora contains diagnostic keys; these are dichotomous keys, which require the user to examine a plant, decide which one of two alternatives given best applies to the plant. Biome — a major regional group of distinctive plant and animal communities Fauna Fauna and Flora Preservation Society Herbal Horticultural flora Megaflora Pharmacopoeia The Plant List Vegetation — a general term for the plant life of a regionCategoriesFlora by continent Flora by country Flora by region eFloras — a collection of on-line floras Chilebosque — checklist of Chilean native flora Flora of NW Europe with descriptions and a quiz to test your knowledge Flora of Australia Online Flora of New Zealand Series Online
Media related to Cyprinodon salinus at Wikimedia Commons