|
Floral Zone
A floral zone is an area with similar distributions of plant species, usually a horizontal belt determined by elevation.Death Valley Expedition (1891), Historic Expeditions, Smithsonian Museum of Natural History/ref> In a historic report on plant distribution in the United States, '' The Death Valley Expedition: A Biological Survey of Parts of California, Nevada, Arizona, and Utah'', naturalist Clinton Hart Merriam describes ''“Most of the desert shrubs are social plants and are distributed in well-marked belts or zones, the vertical limits of which are fixed by the temperature during the period of growth and reproduction.”'' See also * Altitudinal zonation Altitudinal zonation (or elevational zonation) in mountainous regions describes the natural layering of ecosystems that occurs at distinct elevations due to varying environmental conditions. Temperature, humidity, soil composition, and solar r ... * Life zone References Botany {{botany-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes (the archaea and bacteria). By one definition, plants form the clade Viridiplantae (Latin name for "green plants") which is sister of the Glaucophyta, and consists of the green algae and Embryophyta (land plants). The latter includes the flowering plants, conifers and other gymnosperms, ferns and their allies, hornworts, liverworts, and mosses. Most plants are multicellular organisms. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria. Their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elevation
The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Vertical datum). The term ''elevation'' is mainly used when referring to points on the Earth's surface, while ''altitude'' or ''geopotential height'' is used for points above the surface, such as an aircraft in flight or a spacecraft in orbit, and '' depth'' is used for points below the surface. Elevation is not to be confused with the distance from the center of the Earth. Due to the equatorial bulge, the summits of Mount Everest and Chimborazo have, respectively, the largest elevation and the largest geocentric distance. Aviation In aviation the term elevation or aerodrome elevation is defined by the ICAO as the highest point of the landing area. It is often measured in feet and can be found in approach charts of the aerodrome. It is n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A Biological Survey Of Parts Of California, Nevada, Arizona, And Utah
A, or a, is the first letter and the first vowel of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''a'' (pronounced ), plural ''aes''. It is similar in shape to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version can be written in two forms: the double-storey a and single-storey ɑ. The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. In English grammar, " a", and its variant " an", are indefinite articles. History The earliest certain ancestor of "A" is aleph (also written 'aleph), the first letter of the Phoenician alphabet, which consisted entirely of consonants (for that reason, it is also called an abjad to distinguish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clinton Hart Merriam
Clinton Hart Merriam (December 5, 1855 – March 19, 1942) was an American zoologist, mammalogist, ornithologist, entomologist, ecologist, ethnographer, geographer, naturalist and physician. He was commonly known as the 'father of mammalogy', a branch of zoology referring to the study of mammals. Early life Clinton Hart Merriam was born in New York City in 1855 to Clinton Levi Merriam, a U.S. congressman, and Caroline Hart, a judge's daughter and a graduate of Rutgers Institute. The name Clinton, shared by both father and son, was in honor of New York governor DeWitt Clinton, whom the Merriam family had connections with. To avoid confusion, the younger Merriam went by his first initial combined with his middle name, his mother's maiden name, and thus often appears as C. Hart Merriam in both the literature of his time and thereafter. Although born in New York City, where his parents were staying the winter, the family home and place where Merriam spent his boyhood days was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altitudinal Zonation
Altitudinal zonation (or elevational zonation) in mountainous regions describes the natural layering of ecosystems that occurs at distinct elevations due to varying environmental conditions. Temperature, humidity, soil composition, and solar radiation are important factors in determining altitudinal zones, which consequently support different vegetation and animal species. Altitudinal zonation was first hypothesized by geographer Alexander von Humboldt who noticed that temperature drops with increasing elevation. Zonation also occurs in intertidal and marine environments, as well as on shorelines and in wetlands. Scientist C. Hart Merriam observed that changes in vegetation and animals in altitudinal zones map onto changes expected with increased latitude in his concept of life zones. Today, altitudinal zonation represents a core concept in mountain research. Factors A variety of environmental factors determines the boundaries of altitudinal zones found on mountains, ranging f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Life Zone
The life zone concept was developed by C. Hart Merriam in 1889 as a means of describing areas with similar plant and animal communities. Merriam observed that the changes in these communities with an increase in latitude at a constant elevation are similar to the changes seen with an increase in elevation at a constant latitude. The life zones Merriam identified are most applicable to western North America, being developed on the San Francisco Peaks, Arizona and Cascade Range of the northwestern USA. He tried to develop a system that is applicable across the North American continent, but that system is rarely referred to. The life zones that Merriam identified, along with characteristic plants, are as follows: * Lower Sonoran (low, hot desert): creosote bush, Joshua tree * Upper Sonoran (desert steppe or chaparral): sagebrush, scrub oak, Colorado pinyon, Utah juniper * Transition (open woodlands): ponderosa pine * Canadian (fir forest): Rocky Mountain Douglas fir, quaking aspe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
