|
Castilleja Grisea
''Castilleja grisea'' is a rare species of Indian paintbrush known by the common name San Clemente Island Indian paintbrush. It is endemic to San Clemente Island, one of the Channel Islands of California. San Clemente Island is owned by the US Navy so the Navy is involved in a management program to recover this species. Description The San Clemente Island Indian paintbrush is a perennial herb coated densely in long gray hairs. The highly branching stem grows 40 to 60 centimeters tall and bears linear leaves each a few centimeters long. The inflorescence is made up of layers of bracts one to two centimeters long, gray-green in color at the bases and tipped with greenish yellow. Between the bracts emerge dull yellow pouched flowers. The fruit is a capsule about a centimeter long containing tiny seeds with netted surfaces. Distribution This species was once considered to be "relatively common" on its home island.USFWS''Castilleja grisea'' Five-year Review.September, 2007. Since t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castilleja
''Castilleja'', commonly known as paintbrush, Indian paintbrush, or prairie-fire, is a genus of about 200 species of annual and perennial herbaceous plants native to the west of the Americas from Alaska south to the Andes, northern Asia, and one species as far west as the Kola Peninsula in northwestern Russia. These plants are classified in the broomrape family Orobanchaceae (following major rearrangements of the order Lamiales starting around 2001; sources which do not follow these reclassifications may place them in the Scrophulariaceae). They are hemiparasitic on the roots of grasses and forbs. The generic name honors Spanish botanist Domingo Castillejo. Ecology ''Castilleja'' species are eaten by the larvae of some lepidopteran species, including '' Schinia cupes'' (which has been recorded on ''C. exserta'') and ''Schinia pulchripennis'' (which feeds exclusively on ''C. exserta''), and checkerspot butterflies, such as ''Euphydryas'' species. Pollinators aid these plants in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Introduced Species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately or accidentally. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are considered naturalized. The process of human-caused introduction is distinguished from biological colonization, in which species spread to new areas through "natural" (non-human) means such as storms and rafting. The Latin expression neobiota captures the characteristic that these species are ''new'' biota to their environment in terms of established biological network (e.g. food web) relationships. Neobiota can further be divided into neozoa (also: neozoons, sing. neozoon, i.e. animals) and neophyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural History Of The Channel Islands Of California
Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are part of nature, human activity is often understood as a separate category from other natural phenomena. The word ''nature'' is borrowed from the Old French ''nature'' and is derived from the Latin word ''natura'', or "essential qualities, innate disposition", and in ancient times, literally meant "birth". In ancient philosophy, ''natura'' is mostly used as the Latin translation of the Greek word ''physis'' (φύσις), which originally related to the intrinsic characteristics of plants, animals, and other features of the world to develop of their own accord. The concept of nature as a whole, the physical universe, is one of several expansions of the original notion; it began with certain core applications of the word φύσις by pre-Socr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Flora Of California
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Variability
Genetic variability is either the presence of, or the generation of, genetic differences. It is defined as "the formation of individuals differing in genotype, or the presence of genotypically different individuals, in contrast to environmentally induced differences which, as a rule, cause only temporary, nonheritable changes of the phenotype". Genetic variability in a population is important for biodiversity. Causes There are many sources of genetic variability in a population: *Homologous recombination is a significant source of variability. During meiosis in sexual organisms, two homologous chromosomes cross over one another and exchange genetic material. The chromosomes then split apart and are ready to contribute to forming an offspring. Recombination is random and is governed by its own set of genes. Being controlled by genes means that recombination is variable in frequency. *Immigration, emigration, and translocation – each of these is the movement of an individual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Exercise
A military exercise or war game is the employment of military resources in training for military operations, either exploring the effects of warfare or testing strategies without actual combat. This also serves the purpose of ensuring the combat readiness of garrisoned or deployable forces prior to deployment from a home base. While both war games and military exercises aim to simulate real conditions and scenarios for the purpose of preparing and analyzing those scenarios, the distinction between a war game and a military exercise is determined, primarily, by the involvement of actual military forces within the simulation, or lack thereof. Military exercises focus on the simulation of real, full-scale military operations in controlled hostile conditions in attempts to reproduce war time decisions and activities for training purposes or to analyze the outcome of possible war time decisions. War games, however, can be much smaller than full-scale military operations, do not typi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildfire
A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a bushfire(bushfires in Australia, in Australia), desert fire, grass fire, hill fire, peat fire, prairie fire, vegetation fire, or veld fire. Fire ecology, Some natural forest ecosystems depend on wildfire. Wildfires are distinct from beneficial human usage of wildland fire, called controlled burn, controlled burning, although controlled burns can turn into wildfires. Fossil charcoal indicates that wildfires began soon after the appearance of terrestrial plants approximately 419 million years ago during the Silurian period. Earth's carbon-rich vegetation, seasonally dry climates, atmospheric oxygen, and widespread lightning and volcanic ignitions create favorable conditions for fires. The occurre ... [...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 the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromus Madritensis
''Bromus madritensis'' is a species of brome grass known by the common name compact brome. The specific epithet ''madritensis'' refers to Madrid, Spain. It has a diploid number of 28. There are two subspecies: *''Bromus madritensis'' subsp. ''madritensis'': panicles less dense, stem and leaf sheath less hairy *''Bromus madritensis'' subsp. ''rubens'' ( syn. ''Bromus rubens'') – foxtail brome, foxtail chess, red brome: dense panicles and slightly hairy stems Description ''Bromus madritensis'' is an winter annual grass, growing solitary or tufted, with erect or ascending culms growing high. The leaf sheaths are downy or slightly hairy. The grass lacks auricles and the glabrous ligules are long. Its flat leaf blades are either glabrous or slightly hairy, and measure long and wide. The erect and ellipsoid panicles are long and wide, with short branches that ascend and slightly spread. The branches never droop and bear one or two spikelets each. The spikelets are long, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avena Barbata
''Avena barbata'' is a species of wild oat known by the common name slender wild oat. It has edible seeds. It is a diploidized autotetraploid grass (2n=4x=28). Its diploid ancestors are ''A. hirtula'' Lag. and ''A. wiestii'' Steud (2n=2x=14), which are considered Mediterranean and desert ecotypes, respectively, comprising a single species. ''A westie'' and ''A. hirtula'' are widespread in the Mediterranean Basin, growing in mixed stands with ''A. barbata'', though they are difficult to tell apart. This is a winter annual grass with thin tillers (stems) growing up to 60 to 80 centimeters in maximum height, but known to sometimes grow taller. The bristly spikelets are 2 to 3 centimeters long, not counting the bent awn which is up to 4 centimeters in length. ''Avena barbata'' largely reproduces by selfing in natural populations, with very low rates of outcrossing. ''A. barbata'' is native to central Asia (as far east as Pakistan) and the Mediterranean Basin. As an introduced spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromus Diandrus
''Bromus diandrus'' is a species of grass known by the common names great brome and "ripgut brome". Description This is a brome grass which is native to the Mediterranean but has been introduced to much of the rest of the world. It does best in areas with a Mediterranean climate, such as California and parts of southern Australia, but it is quite tolerant of many climates. Ripgut brome is a winter annual that grows throughout winter and spring and matures in the summer. The adult plant is one to three feet in height with hairy, rough leaves about a centimeter wide. The membranous ligule is prominent, white with spiky hairs. The wide panicle nods like that of an oat plant, and it bears a large, splayed spikelet with a very long awn which can exceed five centimeters in length. The seeds easily break out of the spikelet. They are very sharp and very rough due to tiny barb-like hairs that face backward, allowing the seed to catch and lodge-like a fish hook. This characteristic make ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded. Typically, physical erosion procee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Natural History Of The Channel Islands Of California")
.jpg "Click for more on -> Endemic Flora Of California")
