|
Bristlecone Pine
The term bristlecone pine covers three species of pine tree (family Pinaceae, genus ''Pinus'', subsection ''Balfourianae''). All three species are long-lived and highly resilient to harsh weather and bad soils. One of the three species, ''Pinus longaeva'', is among the longest-lived life forms on Earth. The oldest of this species is more than 4,800 years old, making it the oldest known individual of any species. Many scientists are curious as to why this tree is able to live so long. In one study, they discovered that ''Pinus longaeva'' has higher levels of telomerase activity, which further slows or prevents the attrition rate of telomeres. This potentially contributes to the extended life of the bristlecone pine. Despite their potential age and low reproductive rate, bristlecone pines, particularly ''Pinus longaeva'', are usually a first-succession species, tending to occupy new open ground. They generally compete poorly in less-than-harsh environments, making them hard to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Aristata
''Pinus aristata'', the Rocky Mountain bristlecone pine or Colorado bristlecone pine is a long-lived species of bristlecone pine tree native to the United States. It is found in the Rocky Mountains in Colorado and northern New Mexico, with an isolated population in the San Francisco Peaks of Arizona. It is found at very high altitudes, from in cold, dry subalpine climate conditions, often at the tree line, although it also forms extensive closed-canopy stands at somewhat lower elevations. Description ''Pinus aristata'' is a medium-size tree, commonly reaching in height and occasionally as much as in their natural habitat. In favorable conditions they are straight and upright trees, but they become increasingly stunted, short, and twisted the closer they grow to timberline. The crown of the tree is flattened, irregular, or round in shape when fully mature. The trunk can be very substantial, commonly and up to in diameter, and tapers very noticeably towards the top. The bar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Longaeva
''Pinus longaeva'' (commonly referred to as the Great Basin bristlecone pine, intermountain bristlecone pine, or western bristlecone pine) is a long-living species of bristlecone pine tree found in the higher mountains of California, Nevada, and Utah. In 1987, the bristlecone pine was designated one of Nevada's List of U.S. state trees, state trees. Methuselah (pine tree), Methuselah is a Great Basin bristlecone pine that is years old and has been credited as the oldest known living non-Vegetative reproduction, clonal organism on Earth. Description It is a medium-size tree, reaching tall and with a trunk diameter of up to . The bark is bright orange-yellow, thin and scaly at the base of the trunk. The Pine#Foliage, needles are in fascicles of five, stout, long, deep green to blue-green on the outer face, with stomata confined to a bright white band on the inner surfaces. The leaves show the longest persistence of any plant, with some remaining green for 45 years (Ewers & Schm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium
Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic table), it occurs naturally only in combination with other elements and almost always has an oxidation state of +2. It reacts readily with air to form a thin Passivation (chemistry), passivation coating of magnesium oxide that inhibits further corrosion of the metal. The free metal burns with a brilliant-white light. The metal is obtained mainly by electrolysis of magnesium Salt (chemistry), salts obtained from brine. It is less dense than aluminium and is used primarily as a component in strong and lightweight magnesium alloy, alloys that contain aluminium. In the cosmos, magnesium is produced in large, aging stars by the sequential addition of three Helium nucleus, helium nuclei to a carbon nucleus. When such stars explo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium
Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossils of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name comes from Latin ''calx'' " lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and pharmaceuticals for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolomite (rock)
Dolomite (also known as dolomite rock, dolostone or dolomitic rock) is a sedimentary rock, sedimentary carbonate rock that contains a high percentage of the mineral Dolomite (mineral), dolomite, CaMg(CO3)2. It occurs widely, often in association with limestone and evaporites, though it is less abundant than limestone and rare in Cenozoic rock beds (beds less than about 66 million years in age). One of the first geologists to distinguish dolomite from limestone was Déodat Gratet de Dolomieu, a French mineralogist and geologist after whom it is named. He recognized and described the distinct characteristics of dolomite in the late 18th century, differentiating it from limestone. Most dolomite was formed as a magnesium replacement of limestone or of Lime (mineral), lime mud before lithification. The geological process of conversion of calcite to dolomite is known as dolomitization and any intermediate product is known as dolomitic limestone. The "dolomite problem" refers to the v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree Line
The tree line is the edge of a habitat at which trees are capable of growing and beyond which they are not. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually low temperatures, extreme snowpack, or associated lack of available moisture). The tree line is sometimes distinguished from a lower timberline, which is the line below which trees form a forest with a closed Canopy (biology), canopy. At the tree line, tree growth is often sparse, stunted, and deformed by wind and cold. This is sometimes known as (German for "crooked wood"). The tree line often appears well-defined, but it can be a more gradual transition. Trees grow shorter and often at lower densities as they approach the tree line, above which they are unable to grow at all. Given a certain latitude, the tree line is approximately 300 to 1000 meters below the permanent snow line and roughly parallel to it. Causes Due to their vertical s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Owens Valley
Owens Valley (Mono language (California), Mono: ''Payahǖǖnadǖ'', meaning "place of flowing water") is an arid valley of the Owens River in eastern California in the United States. It is located to the east of the Sierra Nevada (U.S.), Sierra Nevada, west of the White Mountains (California), White Mountains and Inyo Mountains, and is split between the Great Basin Desert and the Mojave Desert. The mountain peaks on its west side (including Mount Whitney) reach above in elevation, while the floor of the Owens Valley is at about , making the valley the deepest in the United States. The Sierra Nevada casts the valley in a rain shadow, which makes Owens Valley "the Land of Little Rain". The bed of Owens Lake, now a predominantly dry Endorheic basin, endorheic alkali flat, sits on the southern end of the valley. The current arid nature of the valley is mostly due to the Los Angeles Department of Water and Power diverting the water of the region. The valley provides water to the Los ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green River (Colorado River Tributary)
The Green River, located in the western United States, is the chief tributary of the Colorado River. The watershed of the river, known as the Green River Basin, covers parts of the U.S. states of Wyoming, Utah, and Colorado. The Green River is long, beginning in the Wind River Range of Wyoming and flowing through Wyoming and Utah for most of its course, except for a short segment of in western Colorado. Much of the route traverses the arid Colorado Plateau, where the river has carved some of the most spectacular canyons in the United States. The Green is slightly smaller than Colorado when the two rivers merge but typically carries a larger load of silt. The average yearly mean flow of the river at Green River, Utah is per second. The status of the Green River as a tributary of the Colorado River came about mainly for political reasons. In earlier nomenclature, the Colorado River began at its confluence with the Green River. Above the confluence, Colorado was called the Grand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colorado River
The Colorado River () is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river, the List of longest rivers of the United States (by main stem), 5th longest in the United States, drains an expansive, arid drainage basin, watershed that encompasses parts of seven U.S. states and two Mexican states. The name Colorado derives from the Spanish language for "colored reddish" due to its heavy silt load. Starting in the central Rocky Mountains of Colorado, it flows generally southwest across the Colorado Plateau and through the Grand Canyon before reaching Lake Mead on the Arizona–Nevada border, where it turns south toward the Mexico–United States border, international border. After entering Mexico, the Colorado approaches the mostly dry Colorado River Delta at the tip of the Gulf of California between Baja California and Sonora. Known for its dramatic canyons, whitewater rapids, and eleven National parks of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sierra Nevada (U
The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley (California), Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily in Nevada. The Sierra Nevada is part of the American Cordillera, an almost continuous chain of mountain ranges that forms the western "backbone" of the Americas. The Sierra runs north-south, and its width ranges from to across east–west. Notable features include the General Sherman Tree, the largest tree in the world by volume; Lake Tahoe, the largest alpine lake in North America; Mount Whitney at , the highest point in the contiguous United States; and Yosemite Valley sculpted by glaciers from one-hundred-million-year-old granite, containing List of waterfalls in Yosemite National Park, high waterfalls. The Sierra is home to three national parks, twenty-six wilderness areas, ten national forests, and two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klamath Mountains
The Klamath Mountains are a rugged and lightly populated mountain range in northwestern California and southwestern Oregon in the western United States. As a mountain system within both the greater Pacific Coast Ranges and the California Coast Ranges, the Klamath Mountains have a varied geology, with substantial areas of Serpentine group, serpentinite and marble, and a climate characterized by moderately cold winters with very heavy snowfall and warm, very dry summers with limited rainfall, especially in the south. As a consequence of the geology and soil types, the mountains harbor several endemism, endemic or near-endemic trees, forming one of the largest collections of conifers in the world. The mountains are also home to a diverse array of fish and animal species, including black bears, large cats, owls, eagles, and several species of Pacific salmon. Millions of acres in the mountains are managed by the United States Forest Service. The northernmost and largest sub-range of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arizona
Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the northwest and California to the west, and shares Mexico-United States border, an international border with the Mexican states of Sonora and Baja California to the south and southwest. Its Capital city, capital and List of largest cities, largest city is Phoenix, Arizona, Phoenix, which is the most populous state capital and list of United States cities by population, fifth most populous city in the United States. Arizona is divided into 15 List of counties in Arizona, counties. Arizona is the list of U.S. states and territories by area, 6th-largest state by area and the list of U.S. states and territories by population, 14th-most-populous of the 50 states. It is the 48th state and last of the contiguous United States, contiguous states to be a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
