1.
Franconia Range
–
The Franconia Range is a mountain range located in the White Mountains of the U. S. state of New Hampshire. It is the second-highest range of peaks in the White Mountains, Franconia Ridge is a prominent ridge which forms the backbone of the range, stringing together all of its major summits. The Franconia Range hosts the third largest connected area of tundra in the United States east of the Rocky Mountains, only surpassed by the Presidential Range. Approximately 2.5 miles along the crest of the ridge is in the alpine zone and this area runs from the treeline just below the summit of Little Haystack all the way to the treeline north of Mount Lafayette, and affords constant 360-degree views of the White Mountains. To the east of the lies the rugged and uninhabited Pemigewasset Wilderness. While Mount Liberty and Mount Flume are almost entirely forested, their summits rise just above the treeline, the Franconia Ridge Trail, which coincides with the Appalachian Trail from Mount Lafayette to Mount Liberty, traverses the ridge over all the aforementioned mountains. A popular hike dubbed the Franconia Ridge Loop is an 8.9 miles loop which includes the majority of the portion of the ridge. This loop involves the Falling Waters Trail, the Franconia Ridge Trail, the Greenleaf Trail, the exposed nature of the ridge and the changeable weather of the White Mountains make it a more dangerous hike than it may appear. Injuries and even fatalities from falls and exposure are not uncommon, one man died after he and a companion were trapped February 11,2008, by fast-moving winter weather
2.
White Mountains (New Hampshire)
–
The White Mountains are a mountain range covering about a quarter of the state of New Hampshire and a small portion of western Maine in the United States. They are part of the northern Appalachian Mountains and the most rugged mountains in New England, the range is heavily visited due to its proximity to Boston and, to a lesser extent, New York City and Montreal. Most of the area is land, including the White Mountain National Forest. Its most famous mountain is 6, 288-foot Mount Washington, which is the highest peak in the Northeastern U. S. Mount Washington is part of a line of summits, the Presidential Range, that are named after U. S. presidents and other prominent Americans. The White Mountains also include the Franconia Range, Sandwich Range, Carter-Moriah Range and Kinsman Range in New Hampshire, in all, there are 48 peaks within New Hampshire as well as one in Maine over 4,000 feet, known as the Four-thousand footers. The Whites are known for a system of alpine huts for hikers operated by the Appalachian Mountain Club, the Appalachian Trail crosses the area from southwest to northeast. It is not clear where the name White Mountains came from, there is no record of what Native Americans called the range, although pre-Colonial names for many individual peaks are known. The name and similar such as White Hills or Wine Hills are found in literature from Colonial times. According to tradition, the mountains were first sighted from shipboard off the coast near the Piscataqua estuary, the highest peaks would often be snow-capped, appearing white. An alternate theory is that the granite of the summits looked white to observers. The White Mountains are a section of the larger New England province. The magma intrusions forming the White Mountains today were created 124 to 100 million years ago as the North American Plate moved westward over the New England hotspot, widespread evidence of glaciation may be seen in the U-shaped form of various notches, or mountain passes. Glacial cirques form the heads of Tuckerman Ravine on Mt. Washington, glacial striations are visible at numerous locations, including on the exposed rocks at the summit of Pine Mountain in Gorham. The Mount Washington Auto Road and the historic Mount Washington Cog Railway ascend the ranges highest peak, heavily visited Arethusa Falls, the second tallest waterfall in New Hampshire, lies on a southwest flank of Crawford Notch. The Old Man of the Mountain, a formation on Cannon Mountain that resembled the craggy profile of a mans face, was a White Mountain landmark until it fell in May 2003. It remains the symbol of New Hampshire. The range also includes a feature dubbed The Basin, consisting of a granite bowl,20 feet in diameter, fed by a waterfall. The areas around The Basin are popular spots for swimming in the ice-cold mountain-fed water, some of the earliest maps of the White Mountains were produced as tourist maps and not topographical maps
3.
Venezuelan Andes
–
The Venezuelan Andes also simply known as the Andes in Venezuela, are a mountain system that form the northernmost extension of the Andes. They are fully identified, both by their origin as by the components of the relief, the constituent rocks. The highest point in Venezuela is located in natural region. It covers around 5. 2% of the territory, being the 4th largest natural region in Venezuela. It can be divided in three subregions, Western Venezuelan Andes, north-Eastern Venezuelan Andes Sierra de Perija, located at the western extreme of Venezuela in Zulia state, bordering Colombia. Its characterized by tge interaction of the three most important lithosperic plates in the region, Nazca, Caribbean and South American, a northwest-southwest oriented irection of compression produces vertical and horizontal deformation components, with the formation of thrusts align the Andean borders, and strike-slip faults. The split of Venezuelan Andes apparently began in the Late Eocene, the main active structures are the strike-slip faults. The principal one being the Boconó Fault Zone, with a measured dextral displacement of several millimeters per year, in the field this displacement is shown by the existence of fault trenches, fault depressions, sag ponds, offset ridges and lateral moraines. Like all tropical mountain ranges with altitudes above 3, 000m, the Venezuelan Andes were affected by Pleistocene glaciations. Two morainic complexes have been recognized in the Cordillera de Mérida and these two levels have been considered as Early and Late Stades, respectively, of the Mérida Glaciation. The moraines of the Late Stade are topographically well represented, and several superposed moraines, in the absecence of more detailed data, these have been tentatively assigned to the Late Stade of the Mérida Glaciation. The moraines associated with this phase are most probably located at an altitude of approximately 4,700 m between 100 to 200 below the terminal zone of present-day glaciers
4.
Natural region
–
A natural region is a basic geographic unit. Usually it is a region which is distinguished by its natural features of geography, geology. Thus most natural regions are homogeneous ecosystems, human impact can be an important factor in the shaping and destiny of a particular natural region. The concept natural region may refer to a small, well defined area, or to a large basic geographical unit, the term may also be used generically, like in alpine tundra, or specifically to refer to a particular place. The term is useful where there is no corresponding or coterminous official region. The Fens of eastern England, the Thai highlands, and the Pays de Bray in Normandy, are examples of this. Others might include regions with particular geological characteristics, like badlands, such as the Bardenas Reales, an upland massif of acidic rock, or The Burren, in Ireland
5.
Altitude
–
Altitude or height is defined based on the context in which it is used. As a general definition, altitude is a measurement, usually in the vertical or up direction. The reference datum also often varies according to the context, although the term altitude is commonly used to mean the height above sea level of a location, in geography the term elevation is often preferred for this usage. Vertical distance measurements in the direction are commonly referred to as depth. In aviation, the altitude can have several meanings, and is always qualified by explicitly adding a modifier. Parties exchanging altitude information must be clear which definition is being used, aviation altitude is measured using either mean sea level or local ground level as the reference datum. When flying at a level, the altimeter is always set to standard pressure. On the flight deck, the instrument for measuring altitude is the pressure altimeter. There are several types of altitude, Indicated altitude is the reading on the altimeter when it is set to the local barometric pressure at mean sea level. In UK aviation radiotelephony usage, the distance of a level, a point or an object considered as a point, measured from mean sea level. Absolute altitude is the height of the aircraft above the terrain over which it is flying and it can be measured using a radar altimeter. Also referred to as radar height or feet/metres above ground level, true altitude is the actual elevation above mean sea level. It is indicated altitude corrected for temperature and pressure. Height is the elevation above a reference point, commonly the terrain elevation. Pressure altitude is used to indicate flight level which is the standard for reporting in the U. S. in Class A airspace. Pressure altitude and indicated altitude are the same when the setting is 29.92 Hg or 1013.25 millibars. Density altitude is the altitude corrected for non-ISA International Standard Atmosphere atmospheric conditions, aircraft performance depends on density altitude, which is affected by barometric pressure, humidity and temperature. On a very hot day, density altitude at an airport may be so high as to preclude takeoff and these types of altitude can be explained more simply as various ways of measuring the altitude, Indicated altitude – the altitude shown on the altimeter
6.
Ecotone
–
An ecotone is a transition area between two biomes. It is where two communities meet and integrate and it may be narrow or wide, and it may be local or regional. An ecotone may appear on the ground as a blending of the two communities across a broad area, or it may manifest itself as a sharp boundary line. The word ecotone was coined from a combination of eco plus -tone, from the Greek tonos or tension – in other words, there are several distinguishing features of an ecotone. First, an ecotone can have a sharp transition, with a distinct line between two communities. For example, a change in colors of grasses or plant life can indicate an ecotone, second, a change in physiognomy can be a key indicator. Scientists look at color variations and changes in plant height, third, a change of species can signal an ecotone. There will be specific organisms on one side of an ecotone or the other, other factors can illustrate or obscure an ecotone, for example, migration and the establishment of new plants. These are known as spatial mass effects, which are noticeable because some organisms will not be able to form self-sustaining populations if they cross the ecotone. Lastly, the abundance of species in an ecotone can reveal the type of biome or efficiency of the two communities sharing space. Because an ecotone is the zone in two communities integrate, many different forms of life have to live together and compete for space. Therefore, an ecotone can create a diverse ecosystem, changes in the physical environment may produce a sharp boundary, as in the example of the interface between areas of forest and cleared land. Elsewhere, a more gradually blended interface area will be found, mountain ranges often create such ecotones, due to the wide variety of climatic conditions experienced on their slopes. They may also provide a boundary between species due to the nature of their terrain. Mont Ventoux in France is an example, marking the boundary between the flora and fauna of northern and southern France. Plants in competition extend themselves on one side of the ecotone as far as their ability to maintain themselves allows, beyond this competitors of the adjacent community take over. As a result, the ecotone represents a shift in dominance, ecotones are particularly significant for mobile animals, as they can exploit more than one set of habitats within a short distance. The ecotone contains not only common to the communities on both sides, it may also include a number of highly adaptable species that tend to colonize such transitional areas
7.
Tree line
–
The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and in frigid environments, beyond the tree line, trees cannot tolerate the environmental conditions. The tree line should not be confused with a lower timberline or forest line, at the tree line, tree growth is often sparse and stunted, with the last trees forming densely matted bushes, known as krummholz. The tree line, like other natural lines, appears well-defined from a distance. Trees grow shorter towards the inhospitable climate until they stop growing. The climate above the line of mountains is called an alpine climate. In the northern hemisphere treelines on north-facing slopes are lower than on south-facing slopes because the increased shade on north-facing slopes means the snowpack takes longer to melt and this shortens the growing season for trees. In the southern hemisphere, the slopes have the shorter growing season. The alpine tree line boundary is seldom abrupt, it forms a transition zone between closed forest below and treeless alpine tundra above. Environmentally dwarfed shrubs commonly forms the upper limit, the decrease in air temperature due to increasing elevation causes the alpine climate. Skin effects and topography can create microclimates that alter the general cooling trend, however, the number of degree days calculated from leaf temperatures may be very similar in the two kinds of timberlines. A series of warm summers in the 1940s seems to have permitted the establishment of “significant numbers” of spruce seedlings above the treeline in the hills near Fairbanks. Survival depends on a sufficiency of new growth to support the tree, the windiness of high-elevation sites is also a potent determinant of the distribution of tree growth. However, snow accumulation in sheltered gullies in the Selkirk Mountains of southeastern British Columbia causes timberline to be 400 metres lower than on exposed intervening shoulders. In a desert, the line marks the driest places where trees can grow. These tend to be called the tree line and occur below about 5,000 ft elevation in the Desert Southwestern United States. In some mountainous areas, higher elevations above the line or on equator-facing and leeward slopes can result in low rainfall. This dries out the soil, resulting in an arid environment unsuitable for trees
8.
Krummholz
–
Under these conditions, trees can only survive where they are sheltered by rock formations or snow cover. As the lower portion of these continues to grow, the coverage becomes extremely dense near the ground. Instances of the form of black spruce, Picea mariana, are found in the northern Canadian boreal forests. Krumholtz-form black spruce and balsam fir are abundant in the transition zone of the White Mountains of New Hampshire. Subalpine fir is the most common associate of spruce in krummholz vegetation, lodgepole pine is a minor associate in most of the British Columbia interior, except in dry alpine areas of southwest Cariboo/Chilcotin district where it is abundant. Ericaceous species are common in the accumulation zone around the base of krummholz colonies. A variation of krummholz formation is a tree or banner tree. Branches on the side are killed or deformed by the almost constant strong winds. Where the lower portion of the tree is protected by snow cover or rocks, trade winds in tropical regions near the equator can also shape trees in a similar manner. Divi-divi Elfin forests Reaction wood Windthrow Krumholtz formation in Hudson Bay subarctic landscape
9.
Snow line
–
The climatic snow line is the point above which snow and ice cover the ground throughout the year. The actual snow line may seasonally be significantly lower, the interplay of altitude and latitude affects the precise placement of the snow line at a particular location. At or near the equator, it is situated at approximately 4,500 meters above sea level. In addition, the location to the nearest coastline can influence the altitude of the snow line. A higher altitude is necessary to lower the temperature further against the surroundings. Furthermore, large-scale oceanic currents such as the North Atlantic Current can have significant affects over large areas, the highest mountain in the world below the snow line is Ojos del Salado. Compare the usage of snow line indicating the boundary between snow and non-snow, Frost line Frost line Glacier High Alps Ice cap climate Tree line Charlesworth J. K. With special reference to its glaciation, vol. I, london, Edward Arnold Ltd,700 pp. Flint, R. F. New York, xiii+553+555 pp. Kalesnik, S. V, uchpedgiz, Leningrad,328 pp. Tronov, M. V. Voprosy svyazi mezhdu klimatom i oledeneniem, izdatelstvo Tomskogo Universiteta, Tomsk,202 pp. Wilhelm, F. Schnee- und Gletscherkunde, De Gruyter, Berlin,414 pp
10.
Greenhouse effect
–
The greenhouse effect is the process by which radiation from a planets atmosphere warms the planets surface to a temperature above what it would be without its atmosphere. If a planets atmosphere contains radiatively active gases the atmosphere radiate energy in all directions. Part of this radiation is directed towards the surface, warming it, greenhouse gases in the atmosphere radiate energy, some of which is directed to the surface and lower atmosphere. The mechanism that produces this difference between the surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect. Earth’s natural greenhouse effect is critical to supporting life, human activities, primarily the burning of fossil fuels and clearing of forests, have intensified the natural greenhouse effect, causing global warming. The mechanism is named after a faulty analogy with the effect of radiation passing through glass. The way a greenhouse retains heat is fundamentally different, as a works by reducing airflow. The existence of the effect was argued for by Joseph Fourier in 1824. The effect was more fully quantified by Svante Arrhenius in 1896, however, the term greenhouse was not used to refer to this effect by any of these scientists, the term was first used in this way by Nils Gustaf Ekholm in 1901. Earth receives energy from the Sun in the form of ultraviolet, visible, of the total amount of solar energy available at the top of the atmosphere, about 26% is reflected to space by the atmosphere and clouds and 19% is absorbed by the atmosphere and clouds. Most of the energy is absorbed at the surface of Earth. Because the Earths surface is colder than the photosphere of the Sun, most of this thermal radiation is absorbed by the atmosphere, thereby warming it. In addition to the absorption of solar and thermal radiation, the atmosphere gains heat by sensible, the atmosphere radiates energy both upwards and downwards, the part radiated downwards is absorbed by the surface of Earth. This leads to an equilibrium temperature than if the atmosphere were absent. An ideal thermally conductive blackbody at the distance from the Sun as Earth would have a temperature of about 5.3 °C. However, because Earth reflects about 30% of the incoming sunlight, the surface temperature of this hypothetical planet is 33 °C below Earths actual surface temperature of approximately 14 °C. The basic mechanism can be qualified in a number of ways, the atmosphere near the surface is largely opaque to thermal radiation, and most heat loss from the surface is by sensible heat and latent heat transport. Radiative energy losses become increasingly important higher in the atmosphere, largely because of the concentration of water vapor
11.
Polar climate
–
The polar climate regions are characterized by a lack of warm summers. Every month in a polar climate has a temperature of less than 10 °C. Regions with polar climate cover more than 20% of the Earth, the sun shines for long hours in the summer, and for many fewer hours in the winter. A polar climate results in treeless tundra, glaciers, or a permanent or semi-permanent layer of ice and it has cool summers and very cold winters. There are two types of climate, ET, or tundra climate, and EF, or ice cap climate. A tundra climate is characterized by having at least one month whose average temperature is above 0 °C, in a tundra climate, trees cannot grow, but other specialized plants can grow. In an ice cap climate, no plants can grow, many high altitude locations on Earth have a climate where no month has an average temperature of 10 °C or higher, but as this is due to elevation, this climate is referred to as Alpine climate. Alpine climate can mimic either tundra or ice cap climate, on Earth, the only continent where the ice cap polar climate is predominant is Antarctica. All but a few isolated areas on the island of Greenland also have the ice cap climate. Coastal regions of Greenland that do not have permanent ice sheets have the less extreme tundra climates, large areas in northern Canada and northern Alaska have tundra climate, changing to ice cap climate in the most northern parts of Canada. These subantarctic lowlands are found closer to the equator than the coastal tundras of the Arctic basin, some parts of the Arctic are covered by ice year-round, and nearly all parts of the Arctic experience long periods with some form of ice on the surface. Average January temperatures range from about −40 to 0 °C, average July temperatures range from about −10 to 10 °C, with some land areas occasionally exceeding 30 °C in summer. The Arctic consists of ocean that is surrounded by land. As such, the climate of much of the Arctic is moderated by the ocean water, in summer, the presence of the nearby water keeps coastal areas from warming as much as they might otherwise, just as it does in temperate regions with maritime climates. The climate of Antarctica is the coldest on the whole of Earth, Antarctica has the lowest temperature ever recorded, −89.2 °C at Vostok Station. It is also dry, averaging 166 millimetres of precipitation per year. Even so, on most parts of the continent the snow melts and is eventually compressed to become the glacial ice that makes up the ice sheet. Weather fronts rarely penetrate far into the continent, there have been several attempts at quantifying what constitutes a polar climate
12.
Latitude
–
In geography, latitude is a geographic coordinate that specifies the north–south position of a point on the Earths surface. Latitude is an angle which ranges from 0° at the Equator to 90° at the poles, lines of constant latitude, or parallels, run east–west as circles parallel to the equator. Latitude is used together with longitude to specify the location of features on the surface of the Earth. Without qualification the term latitude should be taken to be the latitude as defined in the following sections. Also defined are six auxiliary latitudes which are used in special applications, there is a separate article on the History of latitude measurements. Two levels of abstraction are employed in the definition of latitude and longitude, in the first step the physical surface is modelled by the geoid, a surface which approximates the mean sea level over the oceans and its continuation under the land masses. The second step is to approximate the geoid by a mathematically simpler reference surface, the simplest choice for the reference surface is a sphere, but the geoid is more accurately modelled by an ellipsoid. The definitions of latitude and longitude on such surfaces are detailed in the following sections. Lines of constant latitude and longitude together constitute a graticule on the reference surface, latitude and longitude together with some specification of height constitute a geographic coordinate system as defined in the specification of the ISO19111 standard. This is of importance in accurate applications, such as a Global Positioning System, but in common usage, where high accuracy is not required. In English texts the latitude angle, defined below, is denoted by the Greek lower-case letter phi. It is measured in degrees, minutes and seconds or decimal degrees, the precise measurement of latitude requires an understanding of the gravitational field of the Earth, either to set up theodolites or to determine GPS satellite orbits. The study of the figure of the Earth together with its field is the science of geodesy. These topics are not discussed in this article and this article relates to coordinate systems for the Earth, it may be extended to cover the Moon, planets and other celestial objects by a simple change of nomenclature. The primary reference points are the poles where the axis of rotation of the Earth intersects the reference surface, the plane through the centre of the Earth and perpendicular to the rotation axis intersects the surface at a great circle called the Equator. Planes parallel to the plane intersect the surface in circles of constant latitude. The Equator has a latitude of 0°, the North Pole has a latitude of 90° North, the latitude of an arbitrary point is the angle between the equatorial plane and the radius to that point. The latitude, as defined in this way for the sphere, is termed the spherical latitude
13.
Himalayas
–
The Himalayas, or Himalaya, form a mountain range in Asia separating the plains of the Indian subcontinent from the Tibetan Plateau. The Himalayan range has the Earths highest peaks, including the highest, the Himalayas include over a hundred mountains exceeding 7,200 metres in elevation. By contrast, the highest peak outside Asia – Aconcagua, in the Andes – is 6,961 metres tall. The Himalayas are spread across five countries, Bhutan, India, Nepal, China, the Himalayan range is bordered on the northwest by the Karakoram and Hindu Kush ranges, on the north by the Tibetan Plateau, and on the south by the Indo-Gangetic Plain. Some of the major rivers, the Indus, the Ganges, and the Tsangpo-Brahmaputra, rise in the Himalayas. The Himalayas have profoundly shaped the cultures of South Asia, many Himalayan peaks are sacred in Hinduism and Buddhism. Lifted by the subduction of the Indian tectonic plate under the Eurasian Plate and its western anchor, Nanga Parbat, lies just south of the northernmost bend of Indus river. Its eastern anchor, Namcha Barwa, is just west of the bend of the Tsangpo river. The range varies in width from 400 kilometres in the west to 150 kilometres in the east, the name of the range derives from the Sanskrit Himā-laya, from himá and ā-laya. They are now known as the Himalaya Mountains, usually shortened to the Himalayas, formerly, they were described in the singular as the Himalaya. This was also previously transcribed Himmaleh, as in Emily Dickinsons poetry and Henry David Thoreaus essays. The mountains are known as the Himālaya in Nepali and Hindi, the Himalaya or The Land of Snow in Tibetan, the Hamaleh Mountain Range in Urdu, the flora and fauna of the Himalayas vary with climate, rainfall, altitude, and soils. The climate ranges from tropical at the base of the mountains to permanent ice, the amount of yearly rainfall increases from west to east along the southern front of the range. This diversity of altitude, rainfall and soil conditions combined with the high snow line supports a variety of distinct plant. The extremes of high altitude combined with extreme cold favor extremophile organisms, the unique floral and faunal wealth of the Himalayas is undergoing structural and compositional changes due to climate change. The increase in temperature is shifting various species to higher elevations, the oak forest is being invaded by pine forests in the Garhwal Himalayan region. There are reports of early flowering and fruiting in some species, especially rhododendron, apple. The highest known tree species in the Himalayas is Juniperus tibetica located at 4,900 metres in Southeastern Tibet, the Himalayan range is one of the youngest mountain ranges on the planet and consists mostly of uplifted sedimentary and metamorphic rock
14.
Alps
–
The mountains were formed over tens of millions of years as the African and Eurasian tectonic plates collided. Extreme shortening caused by the event resulted in marine sedimentary rocks rising by thrusting and folding into high mountain peaks such as Mont Blanc, Mont Blanc spans the French–Italian border, and at 4,810 m is the highest mountain in the Alps. The Alpine region area contains about a hundred peaks higher than 4000 metres, the altitude and size of the range affects the climate in Europe, in the mountains precipitation levels vary greatly and climatic conditions consist of distinct zones. Wildlife such as live in the higher peaks to elevations of 3,400 m. Evidence of human habitation in the Alps goes back to the Palaeolithic era, a mummified man, determined to be 5,000 years old, was discovered on a glacier at the Austrian–Italian border in 1991. By the 6th century BC, the Celtic La Tène culture was well established, Hannibal famously crossed the Alps with a herd of elephants, and the Romans had settlements in the region. In 1800 Napoleon crossed one of the passes with an army of 40,000. The 18th and 19th centuries saw an influx of naturalists, writers, in World War II, Adolf Hitler kept a base of operation in the Bavarian Alps throughout the war. The Alpine region has a cultural identity. The Winter Olympic Games have been hosted in the Swiss, French, at present, the region is home to 14 million people and has 120 million annual visitors. The English word Alps derives from the Latin Alpes, maurus Servius Honoratus, an ancient commentator of Virgil, says in his commentary that all high mountains are called Alpes by Celts. The term may be common to Italo-Celtic, because the Celtic languages have terms for high mountains derived from alp and this may be consistent with the theory that in Greek Alpes is a name of non-Indo-European origin. According to the Old English Dictionary, the Latin Alpes might possibly derive from a pre-Indo-European word *alb hill, Albania, a name not native to the region known as the country of Albania, has been used as a name for a number of mountainous areas across Europe. In Roman times, Albania was a name for the eastern Caucasus, in modern languages the term alp, alm, albe or alpe refers to a grazing pastures in the alpine regions below the glaciers, not the peaks. An alp refers to a mountain pasture where cows are taken to be grazed during the summer months and where hay barns can be found. The Alps are a crescent shaped geographic feature of central Europe that ranges in a 800 km arc from east to west and is 200 km in width, the mean height of the mountain peaks is 2.5 km. The range stretches from the Mediterranean Sea north above the Po basin, extending through France from Grenoble, the range continues onward toward Vienna, Austria, and east to the Adriatic Sea and Slovenia. To the south it dips into northern Italy and to the north extends to the border of Bavaria in Germany
15.
Scandinavian Mountains
–
The Scandinavian Mountains or the Scandes is a mountain range that runs through the Scandinavian Peninsula. The Scandinavian Mountains are often thought to be equivalent to the Scandinavian Caledonides. The western sides of the mountains drop precipitously into the North Sea and Norwegian Sea, forming the fjords of Norway, to the north they form the border between Norway and Sweden, still reaching 2,000 m high at the Arctic Circle. The mountain range just touches northwesternmost Finland, but are more than hills at their northernmost extension at the North Cape. The combination of a location and moisture from the North Atlantic Ocean has caused the formation of many ice fields. In Northern Norway, permafrost becomes common from about 800 to 900 meters AMSL on the western slope, the Scandinavian Montane Birch forest and grasslands terrestrial ecoregion is closely associated with the mountain range. Its names in the Scandinavian languages are, in Swedish Skandinaviska fjällkedjan, Skanderna, Fjällen or Kölen, the names Kölen and Kjølen are often preferentially used for the northern part, where the mountains form a narrow range near the border region of Norway and Sweden. In southern Norway there is a scatter of mountain regions with individual names, such as Dovrefjell, Hardangervidda, Jotunheimen. The mountain chains highest summits are mostly concentrated in an area between Stavanger and Trondheim in southern Norway, with peaks over 1300 m and some peaks over 2000 m. Around Trondheim Fjord peaks decrease in altitude to about 400–500 m rising again to heights in excess of 1900 m further north in Swedish Lapland, the southern part of the mountain range contains the highest mountain of Northern Europe, Galdhøpiggen at almost 2500 m. This part of the chain is also broader and contains a series of plateaux. In south-western Norway the plateaux and gently undulating surfaces are strongly dissected by fjords, the mountain chain is present in Sweden from northern Dalarna northwards, south of this point the Scandinavian Mountains lie completely within Norway. Most of the Scandinavian Mountains lack alpine topography, and where it does have it does relate to altitude, to the east the Scandinavian Mountains proper bounds with mountains that are lower and less dissected and are known as the förfjäll. Generally the förfjäll do not surpass 1000 m. a. s. l, as a geomorphic unit the förfjäll extends across Sweden as a 650 km long and 40 to 80 km broad belt from Dalarna in the south to Norrbotten in the north. The origin of mountain topography is debated by geologists. In Scandinavia the Caledonian Mountains begun a post-orogenic collapse in the Devonian implying tectonic extension, despite occurring in about the same area the ancient Caledonian Mountains and the modern Scandinavian Mountains are unrelated. The Scandinavian Mountains attained its height by tectonic processes different from orogeny, a two-stage model of uplift has been proposed for the Scandinavian Mountains in southern Norway. A first stage in the Mesozoic and a stage starting from the Oligocene
16.
Pyrenees
–
The Pyrenees is a range of mountains in southwest Europe that forms a natural border between France and Spain. For the most part, the main crest forms a divide between France and Spain, with the microstate of Andorra sandwiched in between. The Crown of Aragon and the Kingdom of Navarre have historically extended on both sides of the range, with smaller northern portions now in France and larger southern parts now in Spain. The demonym for the noun Pyrenees in English is Pyrenean, in Greek mythology, Pyrene is a princess who gave her name to the Pyrenees. The Greek historian Herodotus says Pyrene is the name of a town in Celtic Europe, Hercules, characteristically drunk and lustful, violates the sacred code of hospitality and rapes his hosts daughter. Pyrene gives birth to a serpent and runs away to the woods, alone, she pours out her story to the trees, attracting the attention of wild beasts who tear her to pieces. After his victory over Geryon, Hercules passes through the kingdom of Bebryx again, and all the rock-cliffs and wild-beast haunts echo back Pyrene. … The mountains hold on to the name through the ages. Pliny the Elder connects the story of Hercules and Pyrene to Lusitania, the Spanish Pyrenees are part of the following provinces, from east to west, Girona, Barcelona, Lleida, Huesca, Navarra and Gipuzkoa. The French Pyrenees are part of the following départements, from east to west, Pyrénées-Orientales, Aude, Ariège, Haute-Garonne, Hautes-Pyrénées, the independent principality of Andorra is sandwiched in the eastern portion of the mountain range between the Spanish Pyrenees and French Pyrenees. Physiographically, the Pyrenees may be divided into three sections, the Atlantic, the Central, and the Eastern Pyrenees, together, they form a distinct physiographic province of the larger Alpine System division. In the Western Pyrenees, from the Basque mountains near the Bay of Biscay of the Atlantic Ocean, at the eastern end on the southern side lies a distinct area known as the Sub-Pyrenees. On the French side the slopes of the range descend abruptly. The Pyrenees are older than the Alps, their sediments were first deposited in coastal basins during the Paleozoic and Mesozoic eras, the intense pressure and uplifting of the Earths crust first affected the eastern part and moved progressively to the entire chain, culminating in the Eocene Epoch. The eastern part of the Pyrenees consists largely of granite and gneissose rocks, the massive and unworn character of the chain comes from its abundance of granite, which is particularly resistant to erosion, as well as weak glacial development. Low passes are lacking, and the roads and the railroads between France and Spain run only in the lowlands at the western and eastern ends of the Pyrenees. A notable visual feature of mountain range is La Brèche de Roland, a gap in the ridge line. Coal deposits capable of being profitably worked are situated chiefly on the Spanish slopes, the open pit of Trimoun close to the commune of Luzenac is one of the greatest sources of talc in Europe
17.
Carpathian Mountains
–
The Carpathian Mountains or Carpathians are a mountain range system forming an arc roughly 1,500 km long across Central and Eastern Europe, making them the second-longest mountain range in Europe. The Carpathians and their foothills also have many thermal and mineral waters, the Carpathians consist of a chain of mountain ranges that stretch in an arc from the Czech Republic in the northwest through Slovakia, Poland, Hungary and Ukraine to Romania and Serbia. The highest range within the Carpathians is the Tatras, on the border of Slovakia and Poland, the second-highest range is the Southern Carpathians in Romania, where the highest peaks exceed 2,500 m. The divisions of the Carpathians are usually in three sections, Western Carpathians — Czech Republic, Poland, and Slovakia. Eastern Carpathians — southeastern Poland, eastern Slovakia, Ukraine, Romania, the term Outer Carpathians is frequently used to describe the northern rim of the Western and Eastern Carpathians. The most important cities in or near the Carpathians are, Bratislava and Košice in Slovakia, Kraków in Poland, Cluj-Napoca, Sibiu and Braşov in Romania, and Uzhhorod in Ukraine. In modern times, the range is called Karpaty in Czech, Polish, Slovak and Карпати in Ukrainian, Carpați in Romanian, Karpaten in German, Kárpátok in Hungarian and Karpati or Карпати in Serbian. Although the toponym was recorded already by Ptolemy in the 2nd century CE, for instance, Havasok was its medieval Hungarian name, Rus and Romanian chronicles referred to it as Hungarian Mountains. The archaic Polish word karpa meant rugged irregularities, underwater obstacles/rocks, the more common word skarpa means a sharp cliff or other vertical terrain. In late Roman documents, the Eastern Carpathian Mountains were referred to as Montes Sarmatici, the Western Carpathians were called Carpates, a name that is first recorded in Ptolemys Geographia. In the Scandinavian Hervarar saga, which relates ancient Germanic legends about battles between Goths and Huns, the name Karpates appears in the predictable Germanic form as Harvaða fjöllum, inter Alpes Huniae et Oceanum est Polonia by Gervase of Tilbury, has described in his Otia Imperialia in 1211. Thirteenth- to fifteenth-century Hungarian documents named the mountains Thorchal, Tarczal or less frequently Montes Nivium, the northwestern Carpathians begin in Slovakia and southern Poland. They surround Transcarpathia and Transylvania in a semicircle, sweeping towards the southeast. The total length of the Carpathians is over 1,500 km, the highest altitudes of the Carpathians occur where they are widest. The Carpathians cover an area of 190,000 km2 and, after the Alps, although commonly referred to as a mountain chain, the Carpathians do not actually form an uninterrupted chain of mountains. Rather, they consist of several orographically and geologically distinctive groups, the Carpathians at their highest altitude are only as high as the middle region of the Alps, with which they share a common appearance, climate, and flora. The Carpathians are separated from the Alps by the Danube, the two ranges meet at only one point, the Leitha Mountains at Bratislava. The river also separates them from the Balkan Mountains at Orşova in Romania, the valley of the March and Oder separates the Carpathians from the Silesian and Moravian chains, which belong to the middle wing of the great Central Mountain System of Europe
18.
Caucasus Mountains
–
The Caucasus Mountains are a mountain system in Eurasia between the Black Sea and the Caspian Sea in the Caucasus region. The Caucasus Mountains include the Greater Caucasus in the north and Lesser Caucasus in the south, the Greater Caucasus runs west-northwest to east-southeast, from the Caucasian Natural Reserve in the vicinity of Sochi on the northeastern shore of the Black Sea nearly to Baku on the Caspian Sea. The Lesser Caucasus runs parallel to the Greater about 100 km south, the Greater and Lesser Caucasus ranges are connected by the Likhi Range, and to the west and east of the Likhi Range lie the Colchis Plain and the Kur-Araz Lowland. The Meskheti Range is a part of the Lesser Caucasus system, in the southeast the Aras River separates the Lesser Caucasus from the Talysh Mountains which straddle the border of southeastern Azerbaijan and Iran. The highest peak in the Caucasus range is Mount Elbrus in the Greater Caucasus, Mountains near Sochi hosted part of the 2014 Winter Olympics. Geologically, the Caucasus Mountains belong to a system that extends from southeastern Europe into Asia, the Greater Caucasus Mountains are mainly composed of Cretaceous and Jurassic rocks with the Paleozoic and Precambrian rocks in the higher regions. Some volcanic formations are found throughout the range, on the other hand, the Lesser Caucasus Mountains are formed predominantly of the Paleogene rocks with a much smaller portion of the Jurassic and Cretaceous rocks. The Caucasus Mountains formed largely as the result of a plate collision between the Arabian plate moving northwards with respect to the Eurasian plate. As this happened, the rocks that had been deposited in this basin from the Jurassic to the Miocene were folded to form the Greater Caucasus Mountains. This collision also caused the uplift and the Cenozoic volcanic activity in the Lesser Caucasus Mountains, the entire region is regularly subjected to strong earthquakes from this activity. While the Greater Caucasus Mountains have a mainly folded sedimentary structure, the Javakheti Volcanic Plateau in Georgia and the surrounding volcanic ranges which extend well into central Armenia are some of the youngest features of the region. The Kazbek is no active, but the Elbrus erupted in postglacial times. Contemporary seismic activity is a prominent feature of the region, reflecting active faulting, clusters of seismicity occur in Dagestan and in northern Armenia. Many devastating earthquakes have been documented in historical times, including the Spitak earthquake in December 1988 which destroyed the Gyumri-Vanadzor region of Armenia, europes highest mountain is Mount Elbrus 5,642 m in the Caucasus Mountains. Elbrus is 832 m higher than Mont Blanc, the highest peak in the Alps at 4,810 m, the Caucasus Mountains are defined as the continental divide between Asia and Europe for the region between the Black and Caspian Seas. The table below lists some of the highest peaks of the Caucasus, with the exception of Shkhara, the heights are taken from Soviet 1,50,000 mapping. There are higher and more prominent, but nameless, peaks than some of the peaks included below, the climate of the Caucasus varies both vertically and horizontally. Temperature generally decreases as elevation rises, average annual temperature in Sukhumi, Abkhazia at sea level is 15 °C while on the slopes of Mt. Kazbek at an elevation of 3,700 metres, average annual temperature falls to−6.1 °C
19.
Tibetan Plateau
–
It stretches approximately 1,000 kilometres north to south and 2,500 kilometres east to west. Sometimes termed the Third Pole, the Tibetan Plateau contains the headwaters of the basins of most of the streams in surrounding regions. Its tens of thousands of glaciers and other geographical and ecological features serve as a water tower storing water, the impact of global warming on the Tibetan Plateau is of intense scientific interest. The Tibetan Plateau is surrounded by mountain ranges. In the west the curve of the rugged Karakoram range of northern Kashmir embraces the plateau, the Indus River originates in the western Tibetan Plateau in the vicinity of Lake Mansarovar. The Tibetan Plateau is bounded in the north by an escarpment where the altitude drops from around 5,000 metres to 1,500 metres over a horizontal distance of less than 150 kilometres. Along the escarpment is a range of mountains, in the west the Kunlun Mountains separate the plateau from the Tarim Basin. About halfway across the Tarim the bounding range becomes the Altyn-Tagh, in the V formed by this split is the western part of the Qaidam Basin. The Altyn-Tagh ends near the Dangjin pass on the Dunhuang-Golmud road, to the west are short ranges called the Danghe, Yema, Shule, and Tulai Nanshans. The easternmost range is the Qilian Mountains, the line of mountains continues east of the plateau as the Qin Mountains which separate the Ordos Region from Sichuan. North of the runs the Gansu or Hexi Corridor which was the main silk-road route from China proper to the West. The plateau is an arid steppe interspersed with mountain ranges. Annual precipitation ranges from 100 to 300 millimetres and falls mainly as hail, the southern and eastern edges of the steppe have grasslands which can sustainably support populations of nomadic herdsmen, although frost occurs for six months of the year. Permafrost occurs over parts of the plateau. Proceeding to the north and northwest, the plateau becomes progressively higher, colder and drier, here the average altitude exceeds 5,000 metres and winter temperatures can drop to −40 °C. The geological history of the Tibetan Plateau is closely related to that of the Himalayan mountain range, the Himalayas are among the youngest mountain ranges on the planet and consist mostly of uplifted sedimentary and metamorphic rock. Their formation is a result of a collision or orogeny along the convergent boundary between the Indo-Australian Plate and the Eurasian Plate. The collision began in the Upper Cretaceous period about 70 million years ago, since these sediments were light, they crumpled into mountain ranges rather than sinking to the floor
20.
Treeline
–
The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and in frigid environments, beyond the tree line, trees cannot tolerate the environmental conditions. The tree line should not be confused with a lower timberline or forest line, at the tree line, tree growth is often sparse and stunted, with the last trees forming densely matted bushes, known as krummholz. The tree line, like other natural lines, appears well-defined from a distance. Trees grow shorter towards the inhospitable climate until they stop growing. The climate above the line of mountains is called an alpine climate. In the northern hemisphere treelines on north-facing slopes are lower than on south-facing slopes because the increased shade on north-facing slopes means the snowpack takes longer to melt and this shortens the growing season for trees. In the southern hemisphere, the slopes have the shorter growing season. The alpine tree line boundary is seldom abrupt, it forms a transition zone between closed forest below and treeless alpine tundra above. Environmentally dwarfed shrubs commonly forms the upper limit, the decrease in air temperature due to increasing elevation causes the alpine climate. Skin effects and topography can create microclimates that alter the general cooling trend, however, the number of degree days calculated from leaf temperatures may be very similar in the two kinds of timberlines. A series of warm summers in the 1940s seems to have permitted the establishment of “significant numbers” of spruce seedlings above the treeline in the hills near Fairbanks. Survival depends on a sufficiency of new growth to support the tree, the windiness of high-elevation sites is also a potent determinant of the distribution of tree growth. However, snow accumulation in sheltered gullies in the Selkirk Mountains of southeastern British Columbia causes timberline to be 400 metres lower than on exposed intervening shoulders. In a desert, the line marks the driest places where trees can grow. These tend to be called the tree line and occur below about 5,000 ft elevation in the Desert Southwestern United States. In some mountainous areas, higher elevations above the line or on equator-facing and leeward slopes can result in low rainfall. This dries out the soil, resulting in an arid environment unsuitable for trees
21.
Alpine climate
–
Alpine climate is the average weather for the regions above the tree line. This climate is referred to as a mountain climate or highland climate. There are multiple definitions of alpine climate, one simple definition is the climate which causes trees to fail to grow due to cold. According to the Holdridge life zone system, alpine climate occurs when the mean biotemperature of a location is between 1.5 and 3 °C, which prevents tree growth. Biotemperature is defined as the temperature, except all temperatures below 0 °C are treated as 0 °C, in the Köppen climate classification, the alpine climate is part of Group E, along with the polar climate, where no month has a mean temperature higher than 10 °C. The temperature profile of the atmosphere is a result of an interaction between radiation and convection, sunlight in the visible spectrum hits the ground and heats it. The ground then heats the air at the surface, however, when air is hot, it tends to expand, which lowers its density. Thus, hot air tends to rise and transfer heat upward and this is the process of convection. Convection comes to equilibrium when a parcel at air at a given altitude has the density as its surroundings. Air is a conductor of heat, so a parcel of air will rise. This is known as a process, which has a characteristic pressure-temperature curve. As the pressure gets lower, the temperature decreases, the rate of decrease of temperature with elevation is known as the adiabatic lapse rate, which is approximately 9.8 °C per kilometre of altitude. Note that the presence of water in the atmosphere complicates the process of convection, water vapor contains latent heat of vaporization. As air rises and cools, it becomes saturated and cannot hold its quantity of water vapor. The water vapor condenses, and releases heat, which changes the rate from the dry adiabatic lapse rate to the moist adiabatic lapse rate. The actual lapse rate, called the lapse rate, is not constant. Therefore, moving up 100 metres on a mountain is roughly equivalent to moving 80 kilometres towards the pole and this relationship is only approximate, however, since local factors, such as proximity to oceans, can drastically modify the climate. As the altitude increases, the form of precipitation becomes snow
22.
Climate
–
Climate is the statistics of weather, usually over a 30-year interval. Climate differs from weather, in that weather only describes the conditions of these variables in a given region. A regions climate is generated by the system, which has five components, atmosphere, hydrosphere, cryosphere, lithosphere. The climate of a location is affected by its latitude, terrain, climates can be classified according to the average and the typical ranges of different variables, most commonly temperature and precipitation. The most commonly used classification scheme was the Köppen climate classification, the Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region. Paleoclimatology is the study of ancient climates, Climate models are mathematical models of past, present and future climates. Climate change may occur long and short timescales from a variety of factors. For example, a 3°C change in mean annual temperature corresponds to a shift in isotherms of approximately 300–400 km in latitude or 500 m in elevation, therefore, species are expected to move upwards in elevation or towards the poles in latitude in response to shifting climate zones. Climate is commonly defined as the weather averaged over a long period, the standard averaging period is 30 years, but other periods may be used depending on the purpose. Climate also includes statistics other than the average, such as the magnitudes of day-to-day or year-to-year variations, the classical period is 30 years, as defined by the World Meteorological Organization. These quantities are most often surface variables such as temperature, precipitation, Climate in a wider sense is the state, including a statistical description, of the climate system. The World Meteorological Organization describes climate normals as reference points used by climatologists to compare current climatological trends to that of the past or what is considered normal, a Normal is defined as the arithmetic average of a climate element over a 30-year period. A30 year period is used, as it is enough to filter out any interannual variation or anomalies. The WMO originated from the International Meteorological Organization which set up a commission for climatology in 1929. At its 1934 Wiesbaden meeting the commission designated the thirty-year period from 1901 to 1930 as the reference time frame for climatological standard normals. In 1982 the WMO agreed to update climate normals, and in these were completed on the basis of climate data from 1 January 1961 to 31 December 1990. The difference between climate and weather is usefully summarized by the popular phrase Climate is what you expect, weather is what you get. Over historical time spans there are a number of nearly constant variables that determine climate, including latitude, altitude, proportion of land to water and these change only over periods of millions of years due to processes such as plate tectonics
23.
Elevation
–
GIS or geographic information system is a computer system that allows for visualizing, manipulating, capturing, and storage of data with associated attributes. GIS offers better understanding of patterns and relationships of the landscape at different scales, tools inside the GIS allow for manipulation of data for spatial analysis or cartography. A topographical map is the type of map used to depict elevation. In a Geographic Information System, digital models are commonly used to represent the surface of a place. Digital terrain models are another way to represent terrain in GIS, USGS is developing a 3D Elevation Program to keep up with growing needs for high quality topographic data. 3DEP is a collection of enhanced elevation data in the form of high quality LiDAR data over the conterminous United States, Hawaii, there are three bare earth DEM layers in 3DEP which are nationally seamless at the resolution of 1/3,1, and 2 arcseconds. This map is derived from GTOPO30 data that describes the elevation of Earths terrain at intervals of 30 arcseconds and it uses color and shading instead of contour lines to indicate elevation. Hypsography is the study of the distribution of elevations on the surface of the Earth, the term originates from the Greek word ὕψος hypsos meaning height. Most often it is used only in reference to elevation of land, related to the term hypsometry, the measurement of these elevations of a planets solid surface are taken relative to mean datum, except for Earth which is taken relative to the sea level. In the troposphere, temperatures decrease with altitude and this lapse rate is approximately 6.5 °C/km. S
24.
Ocean
–
An ocean is a body of saline water that composes much of a planets hydrosphere. On Earth, an ocean is one of the major divisions of the World Ocean. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern, the word sea is often used interchangeably with ocean in American English but, strictly speaking, a sea is a body of saline water partly or fully enclosed by land. The ocean contains 97% of Earths water, and oceanographers have stated that less than 5% of the World Ocean has been explored, the total volume is approximately 1.35 billion cubic kilometers with an average depth of nearly 3,700 meters. As the world ocean is the component of Earths hydrosphere, it is integral to all known life, forms part of the carbon cycle. The world ocean is the habitat of 230,000 known species, but because much of it is unexplored, the origin of Earths oceans remains unknown, oceans are thought to have formed in the Hadean period and may have been the impetus for the emergence of life. Extraterrestrial oceans may be composed of water or other elements and compounds, the only confirmed large stable bodies of extraterrestrial surface liquids are the lakes of Titan, although there is evidence for the existence of oceans elsewhere in the Solar System. Early in their histories, Mars and Venus are theorized to have had large water oceans. The Mars ocean hypothesis suggests that nearly a third of the surface of Mars was once covered by water, compounds such as salts and ammonia dissolved in water lower its freezing point so that water might exist in large quantities in extraterrestrial environments as brine or convecting ice. Unconfirmed oceans are speculated beneath the surface of many planets and natural satellites, notably. The Solar Systems giant planets are thought to have liquid atmospheric layers of yet to be confirmed compositions. Oceans may also exist on exoplanets and exomoons, including surface oceans of water within a circumstellar habitable zone. Ocean planets are a type of planet with a surface completely covered with liquid. The concept of Ōkeanós has an Indo-European connection, Greek Ōkeanós has been compared to the Vedic epithet ā-śáyāna-, predicated of the dragon Vṛtra-, who captured the cows/rivers. Related to this notion, the Okeanos is represented with a dragon-tail on some early Greek vases, though generally described as several separate oceans, these waters comprise one global, interconnected body of salt water sometimes referred to as the World Ocean or global ocean. This concept of a body of water with relatively free interchange among its parts is of fundamental importance to oceanography. The major oceanic divisions – listed below in descending order of area and volume – are defined in part by the continents, various archipelagos, Oceans are fringed by smaller, adjoining bodies of water such as seas, gulfs, bays, bights, and straits. The Mid-Oceanic Ridge of the World are connected and form the Ocean Ridge, the continuous mountain range is 65,000 km long, and the total length of the oceanic ridge system is 80,000 km long
25.
Precipitation
–
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation include drizzle, rain, sleet, snow, graupel, Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor, so that the water condenses and precipitates. Thus, fog and mist are not precipitation but suspensions, because the vapor does not condense sufficiently to precipitate. Two processes, possibly acting together, can lead to air becoming saturated, Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Short, intense periods of rain in scattered locations are called showers, moisture that is lifted or otherwise forced to rise over a layer of sub-freezing air at the surface may be condensed into clouds and rain. This process is active when freezing rain is occurring. A stationary front is often present near the area of freezing rain, provided necessary and sufficient atmospheric moisture content, the moisture within the rising air will condense into clouds, namely stratus and cumulonimbus. Eventually, the droplets will grow large enough to form raindrops. Lake-effect snowfall can be locally heavy, thundersnow is possible within a cyclones comma head and within lake effect precipitation bands. In mountainous areas, heavy precipitation is possible where upslope flow is maximized within windward sides of the terrain at elevation, on the leeward side of mountains, desert climates can exist due to the dry air caused by compressional heating. The movement of the trough, or intertropical convergence zone. Precipitation is a component of the water cycle, and is responsible for depositing the fresh water on the planet. Approximately 505,000 cubic kilometres of water falls as precipitation each year,398,000 cubic kilometres of it over the oceans and 107,000 cubic kilometres over land. Given the Earths surface area, that means the globally averaged annual precipitation is 990 millimetres, Climate classification systems such as the Köppen climate classification system use average annual rainfall to help differentiate between differing climate regimes. Precipitation may occur on celestial bodies, e. g. when it gets cold, Mars has precipitation which most likely takes the form of frost. Precipitation is a component of the water cycle, and is responsible for depositing most of the fresh water on the planet. Approximately 505,000 km3 of water falls as precipitation each year,398,000 km3 of it over the oceans, given the Earths surface area, that means the globally averaged annual precipitation is 990 millimetres. Mechanisms of producing precipitation include convective, stratiform, and orographic rainfall, Precipitation can be divided into three categories, based on whether it falls as liquid water, liquid water that freezes on contact with the surface, or ice
26.
Wind
–
Wind is the flow of gases on a large scale. On the surface of the Earth, wind consists of the movement of air. Winds are commonly classified by their scale, their speed, the types of forces that cause them, the regions in which they occur. The strongest observed winds on a planet in the Solar System occur on Neptune, Winds have various aspects, an important one being its velocity, another the density of the gas involved, another its energy content or wind energy. In meteorology, winds are referred to according to their strength. Short bursts of high speed wind are termed gusts, strong winds of intermediate duration are termed squalls. Long-duration winds have various names associated with their strength, such as breeze, gale, storm. The two main causes of large-scale atmospheric circulation are the differential heating between the equator and the poles, and the rotation of the planet, within the tropics, thermal low circulations over terrain and high plateaus can drive monsoon circulations. In coastal areas the sea breeze/land breeze cycle can define local winds, in areas that have variable terrain, mountain, Wind powers the voyages of sailing ships across Earths oceans. Hot air balloons use the wind to take trips, and powered flight uses it to increase lift. Areas of wind caused by various weather phenomena can lead to dangerous situations for aircraft. When winds become strong, trees and man-made structures are damaged or destroyed, Winds can shape landforms, via a variety of aeolian processes such as the formation of fertile soils, such as loess, and by erosion. Wind also affects the spread of wildfires, Winds can disperse seeds from various plants, enabling the survival and dispersal of those plant species, as well as flying insect populations. When combined with temperatures, wind has a negative impact on livestock. Wind affects animals food stores, as well as their hunting, Wind is caused by differences in the atmospheric pressure. When a difference in atmospheric pressure exists, air moves from the higher to the pressure area. On a rotating planet, air will also be deflected by the Coriolis effect, globally, the two major driving factors of large-scale wind patterns are the differential heating between the equator and the poles and the rotation of the planet. Outside the tropics and aloft from frictional effects of the surface, near the Earths surface, friction causes the wind to be slower than it would be otherwise
27.
Solar radiation
–
Solar irradiance is the power per unit area received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument. Irradiance may be measured in space or at the Earths surface after atmospheric absorption and it is measured perpendicular to the incoming sunlight. Total solar irradiance, is a measure of the power over all wavelengths per unit area incident on the Earths upper atmosphere. The solar constant is a measure of mean TSI at a distance of one astronomical Unit. Irradiance is a function of distance from the Sun, the solar cycle, Irradiance on Earth is also measured perpendicular to the incoming sunlight. Insolation is the received on Earth per unit area on a horizontal surface. It depends on the height of the Sun above the horizon, the solar irradiance integrated over time is called solar irradiation, solar exposure or insolation. However, insolation is often used interchangeably with irradiance in practice, the SI unit of irradiance is watt per square meter. An alternate unit of measure is the Langley per unit time, the solar energy industry uses watt-hour per square metre per unit time, the relation to the SI unit is thus 1 kW/m2 =24 kWh/m2/day =8760 kWh/m2/year. Irradiance can also be expressed in Suns, where one Sun equals 1000 W/m2 at the point of arrival, part of the radiation reaching an object is absorbed and the remainder reflected. Usually the absorbed radiation is converted to energy, increasing the objects temperature. Manmade or natural systems, however, can convert part of the radiation into another form such as electricity or chemical bonds. The proportion of reflected radiation is the objects reflectivity or albedo, insolation onto a surface is largest when the surface directly faces the sun. As the angle between the surface and the Sun moves from normal, the insolation is reduced in proportion to the angles cosine, see effect of sun angle on climate. In the figure, the angle shown is between the ground and the rather than between the vertical direction and the sunbeam, hence the sine rather than the cosine is appropriate. A sunbeam one mile wide arrives from directly overhead, and another at a 30° angle to the horizontal, the sine of a 30° angle is 1/2, whereas the sine of a 90° angle is 1. Therefore, the angled sunbeam spreads the light over twice the area, consequently, half as much light falls on each square mile. This projection effect is the reason why Earths polar regions are much colder than equatorial regions
28.
Evaporation
–
Evaporation is a type of vaporization of a liquid that occurs from the surface of a liquid into a gaseous phase that is not saturated with the evaporating substance. The other type of vaporization is boiling, which is characterized by bubbles of saturated vapor forming in the liquid phase, steam produced in a boiler is another example of evaporation occurring in a saturated vapor phase. Evaporation that occurs directly from the solid phase below the melting point, on average, a fraction of the molecules in a glass of water have enough heat energy to escape from the liquid. The water in the glass will be cooled by the evaporation until an equilibrium is reached where the air supplies the amount of heat removed by the evaporating water, in an enclosed environment the water would evaporate until the air is saturated. With sufficient temperature, the liquid would turn into vapor quickly, when the molecules collide, they transfer energy to each other in varying degrees, based on how they collide. Sometimes the transfer is so one-sided for a molecule near the surface that it ends up with energy to escape. Evaporation is an part of the water cycle. The sun drives evaporation of water from oceans, lakes, moisture in the soil, in hydrology, evaporation and transpiration are collectively termed evapotranspiration. Evaporation of water occurs when the surface of the liquid is exposed, allowing molecules to escape and form water vapor, when only a small proportion of the molecules meet these criteria, the rate of evaporation is low. Since the kinetic energy of a molecule is proportional to its temperature, as the faster-moving molecules escape, the remaining molecules have lower average kinetic energy, and the temperature of the liquid decreases. This phenomenon is also called evaporative cooling and this is why evaporating sweat cools the human body. Evaporation also tends to proceed quickly with higher flow rates between the gaseous and liquid phase and in liquids with higher vapor pressure. For example, laundry on a line will dry more rapidly on a windy day than on a still day. Three key parts to evaporation are heat, atmospheric pressure, on a molecular level, there is no strict boundary between the liquid state and the vapor state. Instead, there is a Knudsen layer, where the phase is undetermined, because this layer is only a few molecules thick, at a macroscopic scale a clear phase transition interface cannot be seen. It is just that the process is slower and thus significantly less visible. If evaporation takes place in an area, the escaping molecules accumulate as a vapor above the liquid. Many of the return to the liquid, with returning molecules becoming more frequent as the density
29.
Transpiration
–
Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only an amount of water taken up by the roots is used for growth. The remaining 97–99. 5% is lost by transpiration and guttation, leaf surfaces are dotted with pores called stomata, and in most plants they are more numerous on the undersides of the foliage. The stomata are bordered by guard cells and their stomatal accessory cells that open, transpiration also cools plants, changes osmotic pressure of cells, and enables mass flow of mineral nutrients and water from roots to shoots. Two major factors influence the rate of flow from the soil to the roots, the hydraulic conductivity of the soil. Both of these factors influence the rate of flow of water moving from the roots to the stomatal pores in the leaves via the xylem. Mass flow of water from the roots to the leaves is driven in part by capillary action. This movement lowers the potential in the leaf airspace and causes evaporation of liquid water from the mesophyll cell walls. This evaporation increases the tension on the water menisci in the cell walls, water is absorbed at the roots by osmosis, and any dissolved mineral nutrients travel with it through the xylem. The Cohesion-tension theory explains how leaves pull water through the xylem, water molecules stick together, or exhibit cohesion. As a water molecule evaporates from the surface of the leaf, it pulls on the adjacent water molecule, plants regulate the rate of transpiration by controlling the size of the stomatal apertures. The rate of transpiration is also influenced by the demand of the atmosphere surrounding the leaf such as boundary layer conductance, humidity, temperature, wind. Soil water supply and soil temperature can influence stomatal opening, the amount of water lost by a plant also depends on its size and the amount of water absorbed at the roots. Transpiration accounts for most of the loss by a plant by the leaves. Transpiration serves to evaporatively cool plants, as the water carries away heat energy due to its large latent heat of vaporization of 2260 kJ per litre. During a growing season, a leaf will transpire many times more water than its own weight, an acre of corn gives off about 3, 000–4,000 gallons of water each day, and a large oak tree can transpire 40,000 gallons per year. The transpiration ratio is the ratio of the mass of water transpired to the mass of dry matter produced, transpiration rates of plants can be measured by a number of techniques, including potometers, lysimeters, porometers, photosynthesis systems and thermometric sap flow sensors. Isotope measurements indicate transpiration is the component of evapotranspiration
30.
Holdridge life zones
–
The Holdridge life zones system is a global bioclimatic scheme for the classification of land areas. It was first published by Leslie Holdridge in 1947, and updated in 1967 and it is a relatively simple system based on few empirical data, giving objective mapping criteria. A basic assumption of the system is that soil and climax vegetation can be mapped once climate is known. While it was first designed for tropical and subtropical areas, the system applies globally, the system has found a major use in assessing the possible changes in natural vegetation patterns due to global warming. The three axes of the subdivisions are, precipitation biotemperature potential evapotranspiration ratio to mean total annual precipitation. Further indicators incorporated into the system are, humidity provinces latitudinal regions altitudinal belts Biotemperature is based on the season length. It is measured as the mean of all temperatures above freezing, with all temperatures below freezing and above 30 °C adjusted to 0 °C, holdridges system uses biotemperature first, rather than the temperate latitude bias of Merriams life zones, and does not primarily consider elevation. The system is considered appropriate to the complexities of tropical vegetation than Merriams system. Potential evapotranspiration is the amount of water that would be evaporated and transpired if there were sufficient water available, high temperatures result in higher PET. Evapotranspiration is the sum of evaporation and plant transpiration from the Earths land surface to atmosphere, evapotranspiration can never be greater than PET. The ratio, Precipitation/PET, is the aridity index, with an AI<0.2 indicating arid/hyperarid, Coldest /\ / \ PET - -- - Rain Coldest regions have not much evapotranspiration nor precipitation, hence polar deserts
31.
Alpine plant
–
Alpine plants are plants that grow in an alpine climate, which occurs at high elevation and above the tree line. Alpine plants grow together as a plant community in alpine tundra, alpine plants are not a single taxon. Rather, many different plant species live in the alpine environment and these include perennial grasses, sedges, forbs, cushion plants, mosses, and lichens. Alpine plants must adapt to the conditions of the alpine environment, which include low temperatures, dryness, ultraviolet radiation. Some alpine plants serve as medicinal plants, alpine plants occur in a tundra, a type of natural region or biome that does not contain trees. Alpine tundra occurs in mountains worldwide and it transitions to subalpine forests below the tree line, stunted forests occurring at the forest-tundra ecotone are known as Krummholz. With increasing elevation it ends at the line where snow. Alpine plants are not limited to higher latitudes and these areas have different ecology than those located at higher latitudes. One of the biggest distinctions is that the bound of a tropical alpine area is difficult to define due to a mixture of human disturbances, dry climates. The other major difference between tropical and arctic alpine ecology is the temperature differences, the tropics have a summer/winter cycle every day, where as the higher latitudes stay cold both day and night. In the northern latitudes, the factor to overcome is the cold. Intense frost action processes have an effect on what little soil there is. Tropical alpine regions are subject to conditions as well. Because northern alpine areas cover an area it can be difficult to generalize the characteristics that define the ecology. One factor in alpine ecology is wind in an area, wind pruning is a common sight within northern alpine regions. Along with wind pruning, wind erosion of vegetation mats is a common sight throughout Alaska, alpine plants can exist at very high altitudes. For example, there is a moss that grows at 6,480 m on Mount Everest, arenaria bryophylla is the highest flowering plant in the world, occurring as high as 6,180 m. In order to survive, alpine plants are adapted to the conditions at altitudes, including cold, dryness, high levels of ultraviolet radiation
32.
Phacelia sericea
–
Phacelia sericea, the silky phacelia or blue alpine phacelia, is a showy perennial species of Phacelia endemic to western North America. Uncommon, it grows mainly at subalpine to alpine elevations in forest openings or above treeline among rocks, sericea comes from the Latin sericeus, or silky, referring to the fine hairs on the leaves and stem. Phacelia sericea consists of several upright or ascending stems to 0.6 m from a tap-rooted, branched woody base and its leaves are pinnatifid with cleft or entire segments. The basal leaves are larger than the upper cauline leaves and are more persistent. The leaves and stems are covered with silvery silky hairs but are scarcely glandular. The inflorescence consists of several short panicles, tightly packed, at the end of the stem, the dark blue to purple bell-shaped corolla is 4–6 mm across. It is hairy inside and out but not glandular, the filaments are two to three times as long as the corolla and give the inflorescence a fuzzy appearance. The anthers are yellow or orange and the style is shortly cleft. The fruit consists of two-chambered capsules with 8 to 18 seeds and it generally blooms from near the end of May through the end of August. P. sericea ssp. ciliosa is distributed from Oregon and California east to Wyoming, P. sericea ssp. sericea is restricted to the Rocky Mountains, Alaska, British Columbia and Washington. The latter is smaller, more densely hairy, shorter, i. e. less than 0.3 m, with relatively narrow, where the ranges overlap, P. sericea ssp. ciliosa occurs at a lower elevation than ssp. sericea. These are listed as subspecies by the USDA PLANTS database and ITIS, Phacelia sericea is listed by the Federal Highway Administration as a native species suitable for landscaping along roadsides in Colorado
33.
Phlox diffusa
–
Phlox diffusa is a species of phlox known by the common name spreading phlox. It is native to western North America from British Columbia to the southwestern United States to the Dakotas and it is a very compact mat-forming perennial herb growing in cushions or patches of short, decumbent stems. The linear, lance-shaped, or needle-like leaves are no more than 1.5 centimeters long and are arranged in bundles on the short stems. The inflorescence is a solitary tubular flower around a centimeter long and it has a flat white or pale pink or blue corolla with five lobes each just under a centimeter in length. Phlox diffusa is a perennial herb subshrub and its matted to the ground no more than 8 inches tall and its stem is usually prostrate or decumbent to erect. Phlox diffusa has opposite simple pinnate needle like leaves, flowers are quite showy and range from Lavender to pink in color. Flowers have five petals with a corolla that is fused at the base. Phlox diffusa prefers dry hillsides such as areas like rocky slopes, Phlox diffusa is widely distributed throughout the western United States going as far east as Nebraska. It spreads northerly to British Columbia in Canada with its Southern limits being Southern California, based on a study at Chowder ridge fell-view community the flower morphology of Phlox diffusa such as flora color and insect visitors dominated the methods they are pollinated. The study showed that due to early blooming of Phlox diffusa, butterflies and bumblebees visited the flowers less frequently than expected, two minor pollinators for Phlox diffusa are Muscoid flies and Syrphid flies which both visited significantly less. Evidence from this study points to Phlox diffusa being an important nectar source for early season queen bumblebees, Phlox diffusa is a perennial plant which blossoms early May through Mid August which then goes dormant in November until next spring. Media related to Phlox diffusa at Wikimedia Commons Jepson Manual Treatment Washington Burke Museum Photo gallery
34.
Perennial plant
–
A perennial plant or simply perennial is a plant that lives for more than two years. The term is used to differentiate a plant from shorter-lived annuals and biennials. The term is widely used to distinguish plants with little or no woody growth from trees and shrubs. Tomato vines, for example, live several years in their natural habitat but are grown as annuals in temperate regions because they dont survive the winter. There is also a class of evergreen, or non-herbaceous, perennials, an intermediate class of plants is known as subshrubs, which retain a vestigial woody structure in winter, e. g. Penstemon. The local climate may dictate whether plants are treated as shrubs or perennials, for instance, many varieties of Fuchsia are shrubs in warm regions, but in colder temperate climates may be cut to the ground every year as a result of winter frosts. The symbol for a plant, based on Species Plantarum by Linnaeus, is. Perennial plants can be short-lived or they can be long-lived, as are some plants like trees. They include an assortment of plant groups from ferns and liverworts to the highly diverse flowering plants like orchids. Plants that flower and fruit only once and then die are termed monocarpic or semelparous, however, most perennials are polycarpic, flowering over many seasons in their lifetime. Perennials typically grow structures that allow them to adapt to living one year to the next through a form of vegetative reproduction rather than seeding. These structures include bulbs, tubers, woody crowns, rhizomes plus others and they might have specialized stems or crowns that allow them to survive periods of dormancy over cold or dry seasons during the year. Many perennials have developed specialized features that allow them to extreme climatic. Some have adapted to hot and dry conditions or cold temperatures. Those plants tend to invest a lot of resource into their adaptations and often do not flower, Many perennials produce relatively large seeds, which can have an advantage, with larger seedlings produced after germination that can better compete with other plants. Some annuals produce many seeds per plant in one season, while some perennials are not under the same pressure to produce large numbers of seeds. In warmer and more favorable climates, perennials grow continuously, in seasonal climates, their growth is limited to the growing season. In some species, perennials retain their foliage all year round, other plants are deciduous perennials, for example, in temperate regions a perennial plant may grow and bloom during the warm part of the year, with the foliage dying back in the winter
35.
Cyperaceae
–
The Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses and rushes. The family is large, with some 5,500 known species described in about 90 genera and these species are widely distributed, with the centers of diversity for the group occurring in tropical Asia and tropical South America. While sedges may be growing in almost all environments, many are associated with wetlands. Ecological communities dominated by sedges are known as sedgelands, features distinguishing members of the sedge family from grasses or rushes are stems with triangular cross-sections and leaves that are spirally arranged in three ranks. Some well-known sedges include the chestnut and the papyrus sedge. This family also includes cotton-grass, spike-rush, sawgrass, nutsedge or nutgrass, and white star sedge
36.
Forb
–
A forb is a herbaceous flowering plant that is not a graminoid. The term is used in biology and in ecology, especially in relation to grasslands. Forb is derived from the Greek φορβή, pasture or fodder, the spelling phorb is sometimes used, and in older usage this sometimes includes graminids and other plants currently not regarded as forbs. Forbs are members of a guild – a group of plant species with similar growth form. In certain contexts in ecology, guild membership may often be more important than the relationships between organisms. In addition to its use in ecology, the term forb may be used for subdividing popular guides to wildflowers, distinguishing them from other such as grasses, sedges, shrubs. Some examples of forbs are clover, sunflower, daylily, dicotyledon Herbaceous plant Overgrazing United States Department of Agriculture Natural Resources Conservation Service link to Growth habits Codes and Definitions
37.
Root
–
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. Roots can also be aerial or aerating, that is growing up above the ground or especially above water, furthermore, a stem normally occurring below ground is not exceptional either. Therefore, the root is best defined as the non-leaf, non-nodes bearing parts of the plants body, however, important internal structural differences between stems and roots exist. The fossil record of roots – or rather, infilled voids where roots rotted after death – spans back to the late Silurian and their identification is difficult, because casts and molds of roots are so similar in appearance to animal burrows. They can be discriminated using a range of features, the first root that comes from a plant is called the radicle. In response to the concentration of nutrients, roots also synthesise cytokinin, Roots often function in storage of food and nutrients. The roots of most vascular plant species enter into symbiosis with fungi to form mycorrhizae. In its simplest form, the root architecture refers to the spatial configuration of a plant’s root system. This system can be complex and is dependent upon multiple factors such as the species of the plant itself, the composition of the soil. The configuration of root systems serves to support the plant, compete with other plants. Roots grow to specific conditions, which, if changed, can impede a plants growth. For example, a system that has developed in dry soil may not be as efficient in flooded soil, yet plants are able to adapt to other changes in the environment. Root architecture plays the important role of providing a supply of nutrients and water as well as anchorage. The main terms used to classify the architecture of a system are, Branch magnitude. Root angle, the angle of a lateral root’s base around the parent root’s circumference, the angle of a lateral root from its parent root. Link radius, the diameter of a root, all components of the root architecture are regulated through a complex interaction between genetic responses and responses due to environmental stimuli. These developmental stimuli are categorised as intrinsic, the genetic and nutritional influences, or extrinsic, the main hormones and respective pathways responsible for root architecture development include, Auxin – Auxin promotes root initiation, root emergence and primary root elongation. Cytokinins – Cytokinins regulate root apical meristem size and promote lateral root elongation, gibberellins – Together with ethylene they promote crown primordia growth and elongation
38.
Rhizome
–
In botany and dendrology, a rhizome is a modified subterranean stem of a plant that is usually found underground, often sending out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks and rootstocks, Rhizomes develop from axillary buds and are diageotropic or grow perpendicular to the force of gravity. The rhizome also retains the ability to new shoots to grow upwards. If a rhizome is separated into pieces, each piece may be able to rise to a new plant. The plant uses the rhizome to store starches, proteins, and these nutrients become useful for the plant when new shoots must be formed or when the plant dies back for the winter. This is a known as vegetative reproduction and is used by farmers and gardeners to propagate certain plants. This also allows for lateral spread of grasses like bamboo and bunch grasses, examples of plants that are propagated this way include hops, asparagus, ginger, irises, Lily of the Valley, cannas, and sympodial orchids. Some rhizomes which are used directly in cooking include ginger, turmeric, galangal, stored rhizomes are subject to bacterial and fungal infections, making them unsuitable for replanting and greatly diminishing stocks. However, rhizomes can also be produced artificially from tissue cultures, the ability to easily grow rhizomes from tissue cultures leads to better stocks for replanting and greater yields. The plant hormones ethylene and jasmonic acid have found to help induce and regulate the growth of rhizomes. Ethylene that was applied externally was found to affect internal ethylene levels, knowledge of how to use these hormones to induce rhizome growth could help farmers and biologists producing plants grown from rhizomes more easily cultivate and grow better plants. The poplars are an example of trees that propagate using a rhizome, the Pando colony in Utah is a famous example, which has been living for about 80,000 years. In general, rhizomes have short internodes, they send out roots from the bottom of the nodes, a stem tuber is a thickened part of a rhizome or stolon that has been enlarged for use as a storage organ. In general, a tuber is high in starch, for example, the common potato, the term tuber is often used imprecisely, and is sometimes applied to plants with rhizomes. Some plants have rhizomes that grow above ground or that lie at the surface, including some Iris species. Rhizomes generally form a layer, but in Giant Horsetails. Many rhizomes have culinary value, and some, such as zheergen, are consumed raw. Aspen Corm Mycorrhiza Media related to Rhizomes at Wikimedia Commons
39.
Prostrate shrub
–
A prostrate shrub is a woody plant, most of the branches of which lie upon or just above the ground, rather than being held erect as are the branches of most trees and shrubs. Prostration may occur because the tissues in stems are not strong enough to support the weight of the plant. Alternatively, it may occur because of a disposition for branches to grow horizontally on or just under the ground, for example. Prostrate shrubs are used in horticulture as groundcovers and in hanging baskets and they are also important components of rock gardens. The shrinking size of urban gardens has meant an increase in demand for and desirability of dwarf, more recently, prostrate shrubs have received attention for their usefulness in planting green roofs and green walls, where they can contribute to environmental conservation. The windswept coastal heathlands and cliffs of far southeastern New South Wales have yielded Banksia Roller Coaster and Banksia Pygmy Possum. These are flattened varieties of less than 0.5 m in height of the species Banksia integrifolia and Banksia serrata, respectively, both of which grow to sizeable trees of 10 m or more in height. The origin of others is unclear, Cootamundra Wattle is a popular and widely used plant in Australia. Its origin is unknown, possibly a chance seedling in cultivation and it itself is a popular garden plant, its cascading horizontal branches good for rockeries. Alpina is a naturally occurring form of a popular evergreen, many species of Cotoneaster, such as C. apiculatus, are prostrate ornamentals, as are the closely related Pyracanthas, and the humilis variant of sweetbox, Sarcococca hookeriana var. humilis. Heaths and heathers are prostrate shrubs often featured prominently in rock gardens, wintergreens such as Gaultheria humifusa and Gaultheria procumbens are also prostrate growers. Although, strictly speaking, herbaceous, the North American bunchberry, many daphnes, particularly those derived from Daphne odora, are prostrate growers, including forms that are highly fragrant and have variegated leaves, although they are short-lived. Some forms of the culinary herb rosemary form prostrate shrubs when grown in Mediterranean climates, although they die back to the ground when grown where winters are colder
40.
Poaceae
–
Poaceae or Gramineae is a large and nearly ubiquitous family of monocotyledonous flowering plants known as grasses. Poaceae includes the cereal grasses, bamboos and the grasses of natural grassland and cultivated lawns, Grasses have stems that are hollow except at the nodes and narrow alternate leaves borne in two ranks. The lower part of each leaf encloses the stem, forming a leaf-sheath, with ca 780 genera and around 12,000 species, Poaceae are the fifth-largest plant family, following the Asteraceae, Orchidaceae, Fabaceae and Rubiaceae. Grasslands such as savannah and prairie grasses are dominant are estimated to constitute 40. 5% of the land area of the Earth, excluding Greenland. Grasses are also an important part of the vegetation in many habitats, including wetlands, forests. Though commonly called grasses, seagrasses, rushes, and sedges fall outside this family, the rushes and sedges are related to the Poaceae, being members of the order Poales, but the seagrasses are members of order Alismatales. The name Poaceae was given by John Hendley Barnhart in 1895, based on the tribe Poeae described in 1814 by Robert Brown, the term is derived from the Ancient Greek πόα. Grasses include some of the most versatile plant life-forms, a cladogram shows subfamilies and approximate species numbers in brackets, Before 2005, fossil findings indicated that grasses evolved around 55 million years ago. Recent findings of grass-like phytoliths in Cretaceous dinosaur coprolites have pushed this back to 66 million years ago. In 2011, revised dating of the origins of the rice tribe Oryzeae suggested a date as early as 107 to 129 Mya, a multituberculate mammal with grass-eating adaptations seems to suggest that grasses were already around at 120 mya. This separation occurred within the short time span of about 4 million years. Grass leaves are always alternate and distichous, and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem, the leaf blades of many grasses are hardened with silica phytoliths, which discourage grazing animals, some, such as sword grass, are sharp enough to cut human skin. A membranous appendage or fringe of hairs called the ligule lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath, flowers of Poaceae are characteristically arranged in spikelets, each having one or more florets. The spikelets are further grouped into panicles or spikes, the part of the spikelet that bears the florets is called the rachilla. A spikelet consists of two bracts at the base, called glumes, followed by one or more florets, a floret consists of the flower surrounded by two bracts, one external—the lemma—and one internal—the palea. The flowers are usually hermaphroditic—maize being an important exception—and anemophilous or wind-pollinated, the perianth is reduced to two scales, called lodicules, that expand and contract to spread the lemma and palea, these are generally interpreted to be modified sepals. This complex structure can be seen in the image on the right, the fruit of grasses is a caryopsis, in which the seed coat is fused to the fruit wall
This article incorporates public domain material from the Bureau of Land Management document: "Grassland Habitat Group" (PDF). Archived from the original (PDF) on 2008-07-24.
This article incorporates 
Media related to Alpine tundra at Wikimedia Commons