Chernozem is a black-coloured soil containing a high percentage of humus, and high percentages of phosphoric acids and ammonia. Chernozem is very fertile and produces a high agricultural yield, similar soil types occur in Texas and Hungary. Chernozem layer thickness may vary widely, from several inches up to 60 inches in Ukraine, the terrain can be found in small quantities elsewhere. It exists in Northeast China, near Harbin, the only true chernozem in Australia is located around Nimmitabel producing some of the richest soils in the nation. The sale of land has been illegal in Ukraine since 1992. Chernozemic soils are a type in the Canadian system of soil classification
The latter were named Dorian by the ancient Greek writers, after the Dorians, the historical population that spoke them. Greek legend asserts that the Dorians took possession of the Peloponnesus in an event called the Return of the Heracleidae, classical scholars saw in the legend a possibly real event they termed the Dorian invasion. The meaning of the concept has changed several times, as historians, the pattern of arrival of Dorian culture on certain islands in the Mediterranean, such as Crete, is not well understood. The Dorians colonised a number of sites on Crete such as Lato, despite nearly 200 years of investigation, the historicity of a mass migration of Dorians into Greece has never been established, and the origin of the Dorians remains unknown. Some have linked them or their victims with the emergence of the equally mysterious Sea Peoples, the meaning of the phrase Dorian invasion as an explanation for the cultural break after the Mycenaean period has become to some degree amorphous.
Investigations into it have served mainly to rule out various speculations, the Greece to which the tradition refers is the mythic one, now considered to be Mycenaean Greece. The details differ from one ancient author to another, the commonality being that a ruling clan traced its legitimacy to Heracles. The Greek words referring to the influx of the Dorians are katienai and katerchesthai, literally to descend, come down or go down or, less commonly, be brought down. It means a descent from uplands to lowlands, or from earth to grave, or rushing down as a flood, or sweeping down as a wind and this sweeping down upon the Peloponnesus invited the English translation invasion. There is, however, a distinction between Heracleidae and Dorians, george Grote summarizes the relationship as follows, Herakles himself had rendered inestimable aid to the Dorian king Aegimius, when the latter was hard pressed in a contest with the Lapithae. Herakles defeated the Lapithae and slew their king Koronus, in return for which Aegimius assigned to his deliverers one third part of his whole territory and adopted Hyllus as his son.
Hyllus, a Perseid, was driven from the state of Mycenae into exile after the death of Heracles by a rival, another Perseid. Of Herakles, his son Hyllos and his children were expelled and persecuted by Eurystheus. Eurystheus invaded Attica, but perished in the attempt, all the sons of Eurystheus lost their lives. With him, so that the Perseid family was now represented only by the Herakleids, the Pelopid family now assumed power. The Heraclids endeavored to recover the possessions from which they had been expelled but were defeated by the Ionians at the Isthmus of Corinth, Hyllus staked peace for three generations against immediate reoccupation on a single combat and was killed by Echemus of Arcadia. The Heracleidae now found it prudent to claim the Dorian land granted to Heracles, three generations the Heracleidae with Dorian collusion occupied the Peloponnesus, an event Grote terms a victorious invasion. The first widespread use of the term Dorian invasion appears to date to the 1830s, a popular alternative was the Dorian migration
Soil is a mixture of minerals, organic matter, gases and countless organisms that together support life on Earth. Soil is called the Skin of the Earth and interfaces with the lithosphere, the hydrosphere, the atmosphere, the term pedolith, used commonly to refer to the soil, literally translates ground stone. Soil consists of a phase of minerals and organic matter, as well as a porous phase that holds gases. Accordingly, soils are often treated as a system of solids, liquids. Soil is a product of the influence of climate, organisms, Soil continually undergoes development by way of numerous physical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness soil has been considered as an ecosystem by soil ecologists. Most soils have a dry bulk density between 1.1 and 1.6 g/cm3, while the particle density is much higher. Little of the soil of planet Earth is older than the Pleistocene and none is older than the Cenozoic, Soil science has two basic branches of study and pedology.
Edaphology is concerned with the influence of soils on living things, pedology is focused on the formation and classification of soils in their natural environment. In engineering terms, soil is referred to as regolith, or loose material that lies above the solid geology. Soil is commonly referred to as earth or dirt, technically, as soil resources serve as a basis for food security, the international community advocates its sustainable and responsible use through different types of soil governance. Soil is a component of the Earths ecosystem. The worlds ecosystems are impacted in far-reaching ways by the carried out in the soil, from ozone depletion and global warming, to rainforest destruction. Following the atmosphere, the soil is the next largest carbon reservoir on Earth, as the planet warms, soils will add carbon dioxide to the atmosphere due to its increased biological activity at higher temperatures. Thus, soil carbon losses likely have a positive feedback response to global warming.
Since soil has a range of available niches and habitats. A gram of soil can contain billions of organisms, belonging to thousands of species, mostly microbial, Soil has a mean prokaryotic density of roughly 108 organisms per gram, whereas the ocean has no more than 107 procaryotic organisms per milliliter of seawater. Since plant roots need oxygen, ventilation is an important characteristic of soil and this ventilation can be accomplished via networks of interconnected soil pores, which absorb and hold rainwater making it readily available for plant uptake
In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. Trees are not a group but include a variety of plant species that have independently evolved a woody trunk. In looser senses, the palms, the tree ferns, bananas. Trees tend to be long-lived, some reaching several thousand years old, the tallest known tree, a coast redwood named Hyperion, stands 115.6 m high. Trees have been in existence for 370 million years and it is estimated that there are just over 3 trillion mature trees in the world. A tree typically has many secondary branches supported clear of the ground by the trunk and this trunk typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark which serves as a protective barrier, below the ground, the roots branch and spread out widely, they serve to anchor the tree and extract moisture and nutrients from the soil.
Above ground, the divide into smaller branches and shoots. The shoots typically bear leaves, which light energy and convert it into sugars by photosynthesis, providing the food for the trees growth. Flowers and fruit may be present, but some trees, such as conifers, instead have pollen cones and seed cones, such as tree ferns, trees play a significant role in reducing erosion and moderating the climate. They remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissues and forests provide a habitat for many species of animals and plants. Tropical rainforests are one of the most biodiverse habitats in the world, trees provide shade and shelter, timber for construction, fuel for cooking and heating, and fruit for food as well as having many other uses. In parts of the world, forests are shrinking as trees are cleared to increase the amount of available for agriculture. Because of their longevity and usefulness, trees have always revered, with sacred groves in various cultures.
Although tree is a term of common parlance, there is no universally recognised precise definition of what a tree is, either botanically or in common language. In its broadest sense, a tree is any plant with the form of an elongated stem, or trunk. Trees are defined by height, with smaller plants from 0.5 to 10 m being called shrubs
Mycenaean Greece was the last phase of the Bronze Age in Ancient Greece. It represents the first advanced civilization in mainland Greece, with its states, urban organization, works of art. Among the centers of power emerged, the most notable were those of Pylos, Midea in the Peloponnese, Thebes, Athens in Central Greece. The most prominent site was Mycenae, in Argolid, to which the culture of this era owes its name. Mycenaean and Mycenaean-influenced settlements appeared in Epirus, Macedonia, on islands in the Aegean Sea, on the coast of Asia Minor, the Levant and Italy. Their syllabic script, the Linear B, offers the first written records of the Greek language, Mycenaean Greece was dominated by a warrior elite society and consisted of a network of palace states that developed rigid hierarchical, political and economic systems. At the head of society was the king, known as wanax. Various theories have proposed for the end of this civilization. Additional theories such as natural disasters and climatic changes have suggested.
The Mycenaean period became the setting of much ancient Greek literature and mythology. The Bronze Age in mainland Greece is generally termed as the Helladic period by modern archaeologists, after Hellas, the Greek name for Greece. This period is divided into three subperiods, The Early Helladic period was a time of prosperity with the use of metals, the Middle Helladic period faced a slower pace of development, as well as the evolution of megaron-type dwellings and cist grave burials. Finally, the Late Helladic period roughly coincides with Mycenaean Greece, the transition period from the Bronze Age to the Iron Age in Greece is known as Sub-Mycenaean. Moreover, it revealed that the bearers of Mycenaean culture were ethnically connected with the populations that resided in the Greek peninsula after the end of this cultural period. Various collective terms for the inhabitants of Mycenaean Greece were used by Homer in his 8th century BC epic, the Iliad, in reference to the Trojan War. The latter was supposed to have happened in the late 13th – early 12th century BC, Homer used the ethnonyms Achaeans and Argives, to refer to the besiegers.
These names appear to have passed down from the time they were in use to the time when Homer applied them as terms in his Iliad. There is an reference to a-ka-wi-ja-de in the Linear B records in Knossos, Crete dated to c.1400 BC
Veld, spelled veldt, is a type of wide open rural landscape in Southern Africa. Particularly, it is an area covered in grass or low scrub, especially in the countries of South Africa, Swaziland, Botswana. A certain sub-tropical woodland ecoregion of Southern Africa has been defined as the Bushveld by the World Wide Fund for Nature. Trees are found only in a few places—frost and grazing animals allow grass to grow, the word veld comes from the Afrikaans word for field. The etymological origin is older Dutch veldt, a spelling that the Dutch abandoned in favour of veld during the 19th century, decades before the first Afrikaans dictionary. Subsequent addition of the t in the spelling veldt seems to have been mainly an English confusion with the already obsolete Dutch usage. Precipitation mostly occurs in the months in the form of high-energy thunderstorms. Temperature is closely related to elevation, in general, the mean July temperatures range between 45 °F in the Lesotho Highlands and 60 °F in the Lowveld.
January temperatures range between 65 °F and 80 °F, in Zimbabwe the precipitation averages around 30 to 35 inches on the Highveld, dropping to less than 15 inches in the lowest areas of the Lowveld. Temperatures are slightly higher than in South Africa, over the entire veld and annual average rainfall variations of up to 40 percent are common. Damaging drought affects at least half the area about once every three or four years, it reduces plant and animal biomass to sustainable levels again, everywhere the average number of hours of annual sunshine varies from 60 to 80 percent of the total amount possible. Veld can be compared to the Australian terms outback or the bush, to the prairie of North America, to the pampas lowlands of South America. Someone from Yorkshire might equate wandering across the moors to walking through the veld, by extension, the veld can be compared to the boondocks or those places beyond the black stump in Australia. There is a sense in which it refers in essence to unimproved land and these areas are referred to as fields.
The word is appropriate for land that is heavily forested, mountainous. The simplest explanation will be to say the word veld means natural vegetation, excluding vegetation like swamps and it does include mountains with vegetation but not deserts or mountains without natural vegetation. Whereas mountainous peaks and thick forests do not really fit in with the term veld, the word Renosterveld, rhinoceros-field, is now used to differentiate one of the major vegetation types of the Cape Floristic Region. A carefully husbanded sports field on which the game of Rugby is played in the middle of such as Cape Town or Johannesburg is referred to as a rugbyveld in the Afrikaans language
A windbreak is a plantation usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion. They are commonly planted in hedgerows around the edges of fields on farms, if designed properly, windbreaks around a home can reduce the cost of heating and cooling and save energy. Windbreaks are planted to keep snow from drifting onto roadways. Other benefits include contributing to a microclimate around crops, providing habitat for wildlife and intercropping can be combined in a farming practice referred to as alleycropping. Fields are planted in rows of different crops surrounded by rows of trees and these trees provide fruit, wood, or protect the crops from the wind. Alley cropping has been successful in India and Brazil. A further use for a shelterbelt is to screen a farm from a road or motorway. This improves the farm landscape by reducing the visual incursion of the motorway, mitigating noise from the traffic, the term windbreak is used to describe an article of clothing worn to prevent wind chill.
Americans tend to use the term windbreaker whereas Europeans favor the term windbreak, fences called windbreaks are used. Normally made from cotton, nylon and recycled sails, the poles are hammered into the ground and a windbreak is formed. Windbreaks or wind fences are used to wind speeds over erodible areas such as open fields, industrial stockpiles. As erosion is proportional to wind speed cubed a reduction of speed of 1/2 will reduce erosion by over 80%. In essence, when the wind encounters an obstacle such as a windbreak or shelterbelt, air pressure increases on the windward side. As a result, the approaching the barrier is retarded. The result is that wind speed occurs not at or within the windbreak, nor at its downwind edge. Beyond that point wind speed recovers, aided by downward momentum transport from the overlying, faster-moving stream, not only is the mean wind speed reduced in the lee of the shelter, the wind is less gusty, for turbulent wind fluctuations are damped. As a result, turbulent vertical mixing is weaker in the lee of the barrier than it is upwind, of course this effect is attenuated with increasing downwind distance and indeed, beyond about 8H downstream a zone may exist that is actually cooler than upwind.
Wilson,1985, Journal of Wind Engineering & Industrial Aerodynamics, Vol.21 Argete & Wilson,1989, Agricultural & Forest Meteorology, Vol 48 Withgott, environment, The Science Behind the Stories
Nevada is a state in the Western, Mountain West, and Southwestern regions of the United States of America. Nevada is the 7th most extensive, the 34th most populous, nearly three-quarters of Nevadas people live in Clark County, which contains the Las Vegas–Paradise metropolitan area where three of the states four largest incorporated cities are located. Nevada is officially known as the Silver State because of the importance of silver to its history and economy. It is known as the Battle Born State, because it achieved statehood during the Civil War, as the Sage-brush State, for the plant of the same name. Nevada borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, Nevada is largely desert and semi-arid, much of it located within the Great Basin. Areas south of the Great Basin are located within the Mojave Desert, while Lake Tahoe, about 86% of the states land is managed by various jurisdictions of the U. S. federal government, both civilian and military.
Before European contact, Native Americans of the Paiute, the first Europeans to explore the region were Spanish. They called the region Nevada because of the snow covered the mountains in winter. The area formed part of the Viceroyalty of New Spain, the United States annexed the area in 1848 after its victory in the Mexican–American War, and it was incorporated as part of Utah Territory in 1850. The discovery of silver at the Comstock Lode in 1859 led to a boom that became an impetus to the creation of Nevada Territory out of western Utah Territory in 1861. Nevada became the 36th state on October 31,1864, as the second of two added to the Union during the Civil War. Nevada has a reputation for its libertarian laws, in 1940, with a population of just over 110,000 people, Nevada was by far the least-populated state, with less than half the population of the next least-populated state. However, legalized gambling and lenient marriage and divorce laws transformed Nevada into a major tourist destination in the 20th century, Nevada is the only U. S.
state where prostitution is legal, though it is illegal in Clark County, Washoe County and Carson City. The tourism industry remains Nevadas largest employer, with mining continuing as a sector of the economy. The name Nevada comes from the Spanish nevada, meaning snow-covered, most Nevadans pronounce the second syllable of their state name using the vowel of trap. Many from outside the Western United States pronounce it with the vowel of father, although the latter pronunciation is closer to the Spanish pronunciation, it is not the pronunciation preferred by most Nevadans. State Assemblyman Harry Mortenson proposed a bill to recognize the alternate pronunciation of Nevada, though the bill was not supported by most legislators, the Nevadan pronunciation is the de facto official one, since it is the one used by the state legislature. Nevada is almost entirely within the Basin and Range Province, and is broken up by many mountain ranges
South Africa, officially the Republic of South Africa, is the southernmost country in Africa. South Africa is the 25th-largest country in the world by land area and it is the southernmost country on the mainland of the Old World or the Eastern Hemisphere. About 80 percent of South Africans are of Sub-Saharan African ancestry, divided among a variety of ethnic groups speaking different Bantu languages, the remaining population consists of Africas largest communities of European and multiracial ancestry. South Africa is a multiethnic society encompassing a variety of cultures, languages. Its pluralistic makeup is reflected in the recognition of 11 official languages. The country is one of the few in Africa never to have had a coup détat, the vast majority of black South Africans were not enfranchised until 1994. During the 20th century, the black majority sought to recover its rights from the dominant white minority, with this struggle playing a role in the countrys recent history. The National Party imposed apartheid in 1948, institutionalising previous racial segregation, since 1994, all ethnic and linguistic groups have held political representation in the countrys democracy, which comprises a parliamentary republic and nine provinces.
South Africa is often referred to as the Rainbow Nation to describe the multicultural diversity. The World Bank classifies South Africa as an economy. Its economy is the second-largest in Africa, and the 34th-largest in the world, in terms of purchasing power parity, South Africa has the seventh-highest per capita income in Africa. However and inequality remain widespread, with about a quarter of the population unemployed, South Africa has been identified as a middle power in international affairs, and maintains significant regional influence. The name South Africa is derived from the geographic location at the southern tip of Africa. Upon formation the country was named the Union of South Africa in English, since 1961 the long form name in English has been the Republic of South Africa. In Dutch the country was named Republiek van Zuid-Afrika, replaced in 1983 by the Afrikaans Republiek van Suid-Afrika, since 1994 the Republic has had an official name in each of its 11 official languages. Mzansi, derived from the Xhosa noun umzantsi meaning south, is a name for South Africa.
South Africa contains some of the oldest archaeological and human fossil sites in the world, extensive fossil remains have been recovered from a series of caves in Gauteng Province. The area is a UNESCO World Heritage site and has termed the Cradle of Humankind
Temperate grassland regions include the Pampas of Argentina, southern Brazil and Uruguay as well as the steppes of Eurasia. Lands typically referred to as prairie tend to be in North America, the Central Valley of California is a prairie. The Canadian Prairies occupy vast areas of Manitoba, Prairie is the French word for meadow, but the ultimate root is the Latin pratum. The formation of the North American Prairies started with the upwelling of the Rocky Mountains near Alberta, the mountains created a rain shadow that resulted in lower precipitation rates downwind, creating an environment in which most tree species will not tolerate. The parent material of most prairie soil was distributed during the last glacial advance that began about 110,000 years ago, the glaciers expanding southward scraped the landscape, picking up geologic material and leveling the terrain. As the glaciers retreated about 10,000 years ago, it deposited this material in the form of till, wind based loess deposits form an important parent material for prairie soils.
Tallgrass Prairie evolved over tens of thousands of years with the disturbances of grazing, native ungulates such as bison and white-tailed deer, roamed the expansive, plentiful grassland before European colonization of the Americas. For 10, 000-20,000 years native people used fire annually as a tool to assist in hunting, evidence of ignition sources of fire in the tallgrass prairie are overwhelmingly human as opposed to lightning. Humans, and grazing animals, were participants in the process of prairie formation. Fire has the effect on prairies of removing trees, clearing dead plant matter, fire kills the vascular tissue of trees, but not prairie, as up to 75% of the total plant biomass is below the soil surface and will re-grow from its deep roots. Without disturbance, trees will encroach on a grassland, cast shade and widely spaced oak trees evolved to coexist in the oak savanna ecosystem. In spite of long recurrent droughts and occasional torrential rains, the grasslands of the Great Plains were not subject to soil erosion.
The root systems of native prairie grasses firmly held the soil in place to prevent run-off of soil, when the plant died, the fungi, bacteria returned its nutrients to the soil. These deep roots helped native prairie plants reach water in even the driest conditions, the native grasses suffered much less damage from dry conditions than the farm crops currently grown. Prairie in North America is usually split into three groups, wet and dry and they are generally characterized by tallgrass prairie, mixed, or shortgrass prairie, depending on the quality of soil and rainfall. In wet prairies the soil is very moist, including during most of the growing season. The resulting stagnant water is conducive to the formation of bogs, wet prairies have excellent farming soil. The average precipitation amount is 10-30 inches a year, mesic prairie /ˈmiːzɪk/ has good drainage, but good soil during the growing season
Siberia is an extensive geographical region, and by the broadest definition is known as North Asia. Siberia has historically been a part of Russia since the 17th century, the territory of Siberia extends eastwards from the Ural Mountains to the watershed between the Pacific and Arctic drainage basins. It stretches southwards from the Arctic Ocean to the hills of north-central Kazakhstan and to the borders of Mongolia. With an area of 13.1 million square kilometres, Siberia accounts for 77% of Russias land area and this is equivalent to an average population density of about 3 inhabitants per square kilometre, making Siberia one of the most sparsely populated regions on Earth. If it were a country by itself, it would still be the largest country in area, the origin of the name is unknown. Some sources say that Siberia originates from the Siberian Tatar word for sleeping land, another account sees the name as the ancient tribal ethnonym of the Sirtya, a folk, which spoke a language that evolved into the Ugric languages.
This ethnic group was assimilated to the Siberian Tatar people. The modern usage of the name was recorded in the Russian language after the Empires conquest of the Siberian Khanate, a further variant claims that the region was named after the Xibe people. The Polish historian Chycliczkowski has proposed that the name derives from the word for north. He said that the neighbouring Chinese and Mongolians would not have known Russian and he suggests that the name is a combination of two words, su and bir. The region is of significance, as it contains bodies of prehistoric animals from the Pleistocene Epoch. Specimens of Goldfuss cave lion cubs and another woolly mammoth from Oymyakon, a rhinoceros from the Kolyma River. The Siberian Traps were formed by one of the largest known volcanic events of the last 500 million years of Earths geological history. They continued for a million years and are considered a cause of the Great Dying about 250 million years ago. At least three species of human lived in Southern Siberia around 40,000 years ago, H. sapiens, H. neanderthalensis, the last was determined in 2010, by DNA evidence, to be a new species.
Siberia was inhabited by different groups of such as the Enets, the Nenets, the Huns, the Scythians. The Khan of Sibir in the vicinity of modern Tobolsk was known as a prominent figure who endorsed Kubrat as Khagan of Old Great Bulgaria in 630, the Mongols conquered a large part of this area early in the 13th century. With the breakup of the Golden Horde, the autonomous Khanate of Sibir was established in the late 15th century, turkic-speaking Yakut migrated north from the Lake Baikal region under pressure from the Mongol tribes during the 13th to 15th century
Grasslands are areas where the vegetation is dominated by grasses, however sedge and rush families can be found. Grasslands occur naturally on all continents except Antarctica, grasslands are found in most ecoregions of the Earth. For example, there are five terrestrial ecoregion classifications of the grasslands and shrublands biome. Grassland vegetation can vary in height from short, as in chalk grassland, to quite tall, as in the case of North American tallgrass prairie, South American grasslands. Woody plants, shrubs or trees, may occur on some grasslands – forming savannas, scrubby grassland or semi-wooded grassland, as flowering plants and trees, grasses grow in great concentrations in climates where annual rainfall ranges between 500 and 900 mm. The root systems of perennial grasses and forbs form complex mats that hold the soil in place, graminoids are among the most versatile life forms. Existing forest biomes declined, and grasslands became much more widespread, following the Pleistocene ice ages, grasslands expanded in range in the hotter, drier climates, and began to become the dominant land feature worldwide.
Grasslands often occur in areas with annual precipitation between 600 mm and 1,500 mm and average annual temperatures ranges from −5 and 20 °C. However, some occur in colder and hotter climatic conditions. Grassland can exist in habitats that are disturbed by grazing or fire. Grasslands dominated by unsown wild-plant communities can be called natural or semi-natural habitats. The majority of grasslands in temperate climates are semi-natural and these grasslands contain many species of wild plants – grasses, sedges and herbs –25 or more species per square metre is not unusual. Chalk downlands in England can support over 40 species per square metre, in many parts of the world, few examples have escaped agricultural improvement. For example, original North American prairie grasslands or lowland wildflower meadows in the UK are now rare and their associated wild flora equally threatened. Some of the worlds largest expanses of grassland are found in African savanna, grasslands may occur naturally or as the result of human activity.
Grasslands created and maintained by human activity are called anthropogenic grasslands, hunting peoples around the world often set regular fires to maintain and extend grasslands, and prevent fire-intolerant trees and shrubs from taking hold. The tallgrass prairies in the U. S. Midwest may have been extended eastward into Illinois, much grassland in northwest Europe developed after the Neolithic Period, when people gradually cleared the forest to create areas for raising their livestock. Grassland types by Schimper, meadow steppe savannah Grassland types by Ellenberg & Mueller-Dombois, terrestrial herbaceous communities A. Savannas and related grasslands B