1.
NASA World Wind
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World Wind is an open-source virtual globe first developed by NASA in 2003 for use on personal computers and then further developed in concert with the open source community since 2004. As of 2017 a web based version of World Wind is available online, the original version relied on. NET Framework, which ran only on Microsoft Windows. The SDK includes a suite of basic demos, available at goworldwind. org, the World Wind Java version was awarded NASA Software of the Year in November 2009. The program overlays NASA and USGS satellite imagery, aerial photography, topographic maps, Keyhole Markup Language, though widely available since 2003, World Wind was released with the NASA Open Source Agreement license in 2004. The latest Java-based version, was released in December 2016, as of 2015 a web based version of World Wind is under development and available online. An Android version is also available, the previous. NET-based version was an application with an extensive suite of plugins. Apart from the Earth there are worlds, Moon, Mars, Venus, Jupiter. Users could interact with the planet by rotating it, tilting the view. Five million place names, political boundaries, latitude/longitude lines, World Wind. NET provided the ability to browse maps and geospatial data on the internet using the OGCs WMS servers, import ESRI shapefiles and kml/kmz files. This is an example of how World Wind allows anyone to deliver their data, other features of World Wind. NET included support for. X models and advanced visual effects such as atmospheric scattering or sun shading. The resolution inside the US is high enough to discern individual buildings, houses, cars. The resolution outside the US is at least 15 meters per pixel, Microsoft has allowed World Wind to incorporate Virtual Earth high resolution data for non-commercial use. World Wind uses digital elevation model data collected by NASAs Shuttle Radar Topography Mission, National Elevation Dataset and this means one can view topographic features such as the Grand Canyon or Mount Everest in three dimensions. In addition, WW has bathymetry data which allows users to see ocean features, such as trenches and ridges, in 3D. Many people using the applications are adding their own data and are making them available through various sources, such as the World Wind Central or blogs mentioned in the link section below. All images and movies created with World Wind using Blue Marble, Landsat, or USGS public domain data can be modified, re-distributed. World Wind can be expanded by using one of many add-ons - small extensions that add new functionality to the program, plug-in developers can add features to World Wind without changing the programs source code. The original recipe for World Wind was restricted to Windows, relying on the. NET libraries, a new SDK version has been developed in Java with JOGL referred to as World Wind Java
2.
Botswana
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Botswana, officially the Republic of Botswana, is a landlocked country located in Southern Africa. The citizens refer to themselves as Batswana, formerly the British protectorate of Bechuanaland, Botswana adopted its new name after becoming independent within the Commonwealth on 30 September 1966. Since then, it has maintained a tradition of stable representative democracy. Botswana is topographically flat, with up to 70 percent of its territory being the Kalahari Desert and it is bordered by South Africa to the south and southeast, Namibia to the west and north, and Zimbabwe to the northeast. Its border with Zambia to the north near Kazungula is poorly defined, a mid-sized country of just over 2 million people, Botswana is one of the most sparsely populated nations in the world. Around 10 percent of the lives in the capital and largest city. The economy is dominated by mining, cattle, and tourism, Botswana boasts a GDP per capita of about $18,825 per year as of 2015, which is one of the highest in Africa. Its high gross national income gives the country a modest standard of living, Botswana is a member of the African Union, the Southern African Development Community, the Commonwealth of Nations, and the United Nations. The country has been among the hardest hit by the HIV/AIDS epidemic, the death rate due to AIDS or AIDS-related causes has fallen sharply from 2005 to 2013, and the number of new infections in children has also fallen. As of 2014, Botswana has the third-highest prevalence rate for HIV/AIDS, the history of Botswana starts more than 100,000 years ago, when the first humans inhabited the region. The original inhabitants of southern Africa were the Bushmen and Khoi peoples, both speak Khoisan languages and lived as hunter-gatherers. About a thousand years ago, large chiefdoms emerged that were later eclipsed by the Great Zimbabwe empire, around 1300 CE, peoples in present-day Transvaal began to coalesce into three main linguistic and political groups, including the Batswana. The Batswana, a term used also to all citizens of Botswana. Prior to European contact, the Batswana lived as herders and farmers under tribal rule, as groups broke off and moved to new land, new tribes were created. Some human development occurred before the colonial period, during the 1700s, the slave and ivory trades were expanding. To resist these pressures, Shaka, the king of the Zulu Empire, conquered tribes began to move northwest into Botswana, destroying everything in their path. In their efforts to re-establish themselves at the end of period, tribes began to exchange ivory and skins for guns with European traders. Christian missionaries sent from Europe also spread to the interior, often at the invitation of tribal chiefs who wanted guns, by 1880 every major village had a resident missionary, and their influence became permanent
3.
Namibia
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Namibia, officially the Republic of Namibia, is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south, although it does not border Zimbabwe, a part of less than 200 metres of the Zambezi River separates the two countries. Namibia gained independence from South Africa on 21 March 1990, following the Namibian War of Independence. Its capital and largest city is Windhoek, and it is a state of the United Nations, the Southern African Development Community, the African Union. The dry lands of Namibia were inhabited since early times by the San, Damara, since about the 14th century, immigrating Bantu peoples arrived as part of the Bantu expansion. Since then the Bantu groups in total, known as the Ovambo people, have dominated the population of the country, in the late 19th century during European colonization, the German Empire established rule over most of the territory as a protectorate in 1884. It began to develop infrastructure and farming, and maintained this German colony until 1915, after the end of World War I, in 1920 the League of Nations mandated the country to the United Kingdom, under administration by South Africa. It imposed its laws, including racial classifications and rules, from 1948, with the National Party elected to power, South Africa applied apartheid also to what was known as South West Africa. In 1878 the Cape of Good Hope had annexed the port of Walvis Bay and the offshore Penguin Islands, following continued guerrilla warfare, South Africa installed an interim administration in Namibia in 1985. Namibia obtained full independence from South Africa in 1990, but Walvis Bay and the Penguin Islands remained under South African control until 1994. Namibia has a population of 2.1 million people and a stable multi-party parliamentary democracy, Agriculture, herding, tourism and the mining industry – including mining for gem diamonds, uranium, gold, silver, and base metals – form the basis of its economy. The large, arid Namib Desert has resulted in Namibia being overall one of the least densely populated countries in the world, Namibia enjoys high political, economic and social stability. The name of the country is derived from the Namib Desert, before its independence in 1990, the area was known first as German South-West Africa, then as South-West Africa, reflecting the colonial occupation by the Germans and the South Africans. The dry lands of Namibia were inhabited since early times by San, Damara, from about the 14th century, immigrating Bantu peoples arrived during the Bantu expansion from central Africa. From the late 18th century onwards, Oorlam people from Cape Colony crossed the Orange River and their encounters with the nomadic Nama tribes were largely peaceful. The missionaries accompanying the Oorlam were well received by them, the right to use waterholes, on their way further northwards, however, the Oorlam encountered clans of the Herero at Windhoek, Gobabis, and Okahandja, who resisted their encroachment. The Nama-Herero War broke out in 1880, with hostilities ebbing only after the German Empire deployed troops to the places and cemented the status quo among the Nama, Oorlam. The first Europeans to disembark and explore the region were the Portuguese navigators Diogo Cão in 1485 and Bartolomeu Dias in 1486, like most of interior Sub-Saharan Africa, Namibia was not extensively explored by Europeans until the 19th century
4.
South Africa
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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, Asian, 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, however, 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, poverty and inequality remain widespread, with about a quarter of the population unemployed, nevertheless, 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
5.
Orange River
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The Orange River is the longest river in South Africa. It rises in the Drakensberg mountains in Lesotho, flowing westwards through South Africa to the Atlantic Ocean, the river forms part of the international borders between South Africa and Namibia and between South Africa and Lesotho, as well as several provincial borders within South Africa. Except for Upington, it does not pass any major cities. The Orange River plays an important role in the South African economy by providing water for irrigation, the river was named by Robert Jacob Gordon after the Dutch Royal House. Other names include Gariep River, Groote River or Senqu River, the official name, however, is the Orange River. The Orange rises in the Drakensberg mountains along the border between South Africa and Lesotho, about 193 km west of the Indian Ocean and at an altitude of over 3,000 m. While in Lesotho, the river is known as the Senqu and parts of it freeze in winter and this creates droughts downstream of it which mainly affects goat and cattle production. The river then runs westward through South Africa, forming the boundary of the Free State province. In this section the river flows first into the Gariep Dam, from the border of Lesotho to below the Van der Kloof Dam the river bed is deeply incised. Further downstream the land is flatter, and the river is used extensively for irrigation. At the western point of the Free State, southwest of Kimberley, the Orange meets with its tributary, the Vaal River. From here it flows westward for 550 km, forming the border between the province and Namibias ǁKaras Region. On the border, the passes the town of Vioolsdrif. In the last 800 km of its course the Orange receives many intermittent streams, in this section, the Namib Desert terminates on the north bank of the river, so under normal circumstances the volume of water added by these tributaries is negligible. Here the bed of the river is again deeply incised. The Augrabies Falls are located on section of the Orange. The Orange empties into the Atlantic Ocean at Alexander Bay, which lies equidistant between Cape Town and Walvis Bay. Some 33 km from its mouth it is obstructed by rapids
6.
Brandberg Mountain
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The Brandberg, is Namibias highest mountain. Brandberg Mountain is located in former Damaraland, now Erongo, in the northwestern Namib Desert, near the coast, and covers an area of approximately 650 km². With its highest point, the Königstein, standing at 2,573 m above sea level and located on the flat Namib gravel plains, on a clear day The Brandberg can be seen from a great distance. There are various routes to the summit, the easiest being up the Gaaseb river valley, the nearest settlement is Uis, roughly 30 km from the mountain. The name Brandberg is Afrikaans, Dutch and German for Fire Mountain, the Damara name for the mountain is Dâures, which means burning mountain, while the Herero name, Omukuruvaro means mountain of the Gods. The Brandberg Massif or Brandberg Intrusion is an intrusion, which forms a dome-shaped massif. It originated during Early Cretaceous rifting that led to the opening of the South Atlantic Ocean, argon–argon dating yielded intrusive ages of 132 to 130 Ma. The dominant plutonic rock is a medium grained biotite-hornblende granite. In the western interior of the massif, a 2 km in diameter body of pyroxene-bearing monzonite is exposed, the youngest intrusive rocks based on cross-cutting relations are arfvedsonite granite dikes and sills in the southwestern periphery of the Brandberg massif which crop out in the Amis valley. The arfvedsonite granites contain minerals rich in rare earth element minerals such as pyrochlore, remnants of Cretaceous volcanic rocks are preserved in a collar along the western and southern margins of the massif. Their angle of dip increases towards the contact where clasts of country-rock occur within the forming a magmatic breccia. Erosion subsequently removed the overburden rock, apatite fission track dating indicates approximately 5 km denudation between 80 and 60 Ma. An associated feature is the Doros Complex, the Brandberg is a spiritual site of great significance to the San tribes. The main tourist attraction is The White Lady rock painting, located on a face with other art work, under a small rock overhang. The ravine contains more than 1000 rock shelters, as well as more than 45000 rock paintings, to reach The White Lady it is necessary to hike for about 40 minutes over rough terrain, along the ancient watercourses threading through the mountain. The higher elevations of the mountain contain hundreds of rock paintings, most of which have been painstakingly documented by Harald Pager. Pagers work was published by the Heinrich Bart Institute, in the six volume series Rock Paintings of the Upper Brandberg edited by Tilman Lenssen-Erz. The Brandberg is also home to some interesting desert flora, Damaraland is well known for its grotesque aloes and euphorbias and the region around the mountain is no exception
7.
Vachellia erioloba
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Vachellia erioloba (camel thorn, giraffe thorn is a tree of southern Africa in the family Fabaceae. Its preferred habitat is the dry sandy soils in parts of South Africa, Botswana. It is also native to Angola, south-west Mozambique, Zambia, the tree was first described by Ernst Heinrich Friedrich Meyer and Johann Franz Drège in 1836. The camel thorn is a tree in South Africa. The tree can grow up to 17 metres high and it is slow-growing, very hardy to drought and fairly frost-resistant. The wood is dark reddish-brown in colour and extremely dense and strong and it is a good for fires, which leads to widespread clearing of dead trees and the felling of healthy trees. It produces ear-shaped pods, favoured by a number of herbivores including cattle. The seeds can be roasted and used as a substitute for coffee beans, the name camel thorn refers to the fact that giraffe commonly feed on the leaves with their specially-adapted tongue and lips that can avoid the thorns. The scientific name erioloba means wooly lobe, a reference to the ear-shaped pods Dressler, S. Schmidt, M. & Zizka, african plants – a Photo Guide
8.
Semi-arid climate
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A semi-arid climate or steppe climate is the climate of a region that receives precipitation below potential evapotranspiration, but not extremely. There are different kinds of climates, depending on such variables as temperature. Semi-arid climates tend to short or scrubby vegetation, with semi-arid areas usually dominated by either grasses or shrubs. To determine if a location has a climate, the precipitation threshold must first be determined. If the areas precipitation is less than the threshold but more than half the threshold. Hot semi-arid climates tend to be located in the tropics and subtropics and these climates tend to have hot, sometimes extremely hot, summers and warm to cool winters, with some to minimal precipitation. Hot semi-arid climates are most commonly found around the fringes of subtropical deserts, hot semi-arid climates are most commonly found in Africa, Australia and South Asia. In Australia, a portion of the Outback surrounding the central desert regions lies within the hot semi-arid climate regime. Hot semi-arid climates can also be found in North America, primarily in Mexico, areas of Texas near Mexico, cold semi-arid climates tend to be located in temperate zones or elevated portions in subtropical zones. They are typically found in continental interiors some distance from bodies of water. Cold semi-arid climates usually feature warm and dry summers, though their summers are not quite as hot as those of hot semi-arid climates. Unlike hot semi-arid climates, areas with cold semi-arid climates tend to have cold winters and these areas usually see some snowfall during the winter, though snowfall is much lower than at locations at similar latitudes with more humid climates. These large diurnal temperature variations are seen in hot semi-arid climates. Cold semi-arid climates are most commonly found in Asia and North America, however, they can also be found in Northern Africa, South Africa, Europe, sections of South America and sections of interior southern Australia and New Zealand. As a result of this, some areas can have climates that are classified as hot or cold depending on the isotherm used. One such location is San Diego, California, which has cool summers for the due to prevailing winds off the ocean. Arid Forest Research Institute Continental climate Dust Bowl Goyders Line Pallisers Triangle Köppen climate classification Wave height Ustic
9.
Savanna
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A savanna or savannah is a mixed woodland grassland ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support a herbaceous layer consisting primarily of grasses. Savannas maintain an open canopy despite a high tree density and it is often believed that savannas feature widely spaced, scattered trees. However, in savannas, tree densities are higher and trees are more regularly spaced than in forests. Savanna covers approximately 20% of the Earths land area, the word originally entered English in 1555 as the Latin Zauana, equivalent in the orthography of the times to zavana. Peter Martyr reported it as the name for the plain around Comagre. The accounts are inexact, but this is placed in present-day Madugandí or at points on the nearby Guna Yala coast opposite Ustupo or on Point Mosquitos. These areas are now given over to modern cropland or jungle. The common usage meaning to describe vegetation now conflicts with a simplified yet widespread climatic concept meaning, the divergence has sometimes caused areas such as extensive savannas north and south of the Congo and Amazon Rivers to be excluded from mapped savanna categories. Barrens has been used almost interchangeably with savanna in different parts of North America, sometimes midwestern savanna were described as grassland with trees. Different authors have defined the limits of savanna tree coverage as 5–10%. Two factors common to all environments are rainfall variations from year to year. In the Americas, e. g. in Belize, Central America, savanna vegetation is similar from Mexico to South America, savannas are subject to regular wildfires and the ecosystem appears to be the result of human use of fire. For example, Native Americans created the Pre-Columbian savannas of North America by periodically burning where fire-resistant plants were the dominant species, pine barrens in scattered locations from New Jersey to coastal New England are remnants of these savannas. Aboriginal burning appears to have responsible for the widespread occurrence of savanna in tropical Australia and New Guinea. The maquis shrub savannas of the Mediterranean region were created and maintained by anthropogenic fire. These fires are usually confined to the layer and do little long term damage to mature trees. However, these either kill or suppress tree seedlings, thus preventing the establishment of a continuous tree canopy which would prevent further grass growth
10.
Southern Africa
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Southern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics, and including several countries. The term southern Africa or Southern Africa, generally includes Angola, Botswana, Lesotho, Malawi, Mozambique, Namibia, South Africa, Swaziland, Zambia, from a political perspective the region is said to be unipolar with South Africa as a first regional power. It is not used in political, economic or human geography contexts because this definition cuts Mozambique in two, the Southern African Development Community was established in 1980 to facilitate co-operation in the region. Comoros, Madagascar, Malawi, Mayotte, Mauritius, Mozambique, Réunion, Seychelles, Zambia, the Democratic Republic of the Congo and Tanzania, though more commonly reckoned in Central and Eastern Africa, respectively, are occasionally included in Southern Africa as they are SADC members. The terrain of Southern Africa is varied, ranging from forest, the region has both low-lying coastal areas, and mountains. While colonialism has left its mark on the development over the course of history, today poverty, corruption, the pursuit of economic and political stability is an important part of the regions goals, as demonstrated by the SADC. In terms of strength, South Africa is by far the dominant power of the region. South Africas GDP alone is many times greater than the GDPs of all countries in the region. Southern Africa has a diversity of ecoregions including grassland, bushveld, karoo, savannah. It has complex Plateaus that create massive mountain structures along the South African border, there are numerous environmental issues in Southern Africa, including air pollution and desertification. Southern Africa is home to cultures and people. It was once populated by San, Khoikhoi and Pygmies in widely dispersed concentrations, the process of colonization and settling resulted in a significant population of European and Asian descent in many southern African countries. These factors vary from country to country, for example, the Democratic Republic of Congo has favourable climatic and physical conditions, but performs far below its capacity in food provision due to political instability and poor governance. The Republic of South Africa is a food producer and exporter in the region. However this data might not fully capture the reality of a region with high urban populations, urban food security has been noted as an emerging area of development concern in the region, with recent data showing high levels of food insecurity amongst low-income households. In South Africa for example, while over 50% experience hunger, there is only limited data on the other Southern African countries. History of Southern Africa Sub-Saharan Africa Southern Africa
11.
Tswana language
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The Tswana language, Setswana, is a language spoken in southern Africa by about five million people. Tswana is a language and lingua franca of Botswana. The two South African provinces with largest number of speakers are Gauteng Province and North West Province, until 1994, South African Tswana people were notionally citizens of Bophuthatswana, one of the bantustans of the apartheid regime. The first European to describe the Tswana language was the German traveller H. Lichtenstein and he mistakenly regarded Tswana as a dialect of the Xhosa language, and the name he used for the language Beetjuana may also have covered the Northern- and Southern Sotho languages. In the following years he published other books of the Bible. Masego was the first to speak the language, the first grammar of the Tswana language was published in 1833 by the missionary James Archbell, although it was modelled on a Xhosa grammar. The first grammar of Tswana which regarded it as a language from Xhosa was published by the French missionary E. Casalis in 1841. He changed his mind later, and in a publication from 1882 he noted that the Northern-, in 1876 the South African intellectual and linguist Solomon Plaatje was born, and he became one of the first writers to extensively write in and about the Tswana language. The vowel inventory of Tswana can be seen below, some dialects have two additional vowels, the close-mid vowels /e/ and /o/. The consonant inventory of Tswana can be seen below, the consonant /d/ is merely an allophone of /l/, when the latter is followed by the vowels /i/ or /u/. Tswana also has three click consonants, but these are used in interjections or ideophones, and tend only to be used by the older generation. The three click consonants are the dental click /ǀ/, orthographically ⟨c⟩, the lateral click /ǁ/, orthographically ⟨x⟩, there are some minor dialectal variations among the consonants between speakers of Tswana. For instance, /χ/ is realised as either /x/ or /h/ by many speakers, /f/ is realised as /h/ in most dialects, and /tɬ/ and /tɬʰ/ are realised as /t/ and /tʰ/ in northern dialects. Stress is fixed in Tswana and thus falls on the penult of a word. The syllable on which the falls is lengthened. Tswana has two tones, high and low, although the latter has a wider distribution in words than the former. Tones are not marked orthographically which may lead to ambiguity, if a syllable bears a high tone, the following two syllables will also get high tones, unless they are at the end of the word. The nine classes and their respective prefixes can be seen below, some nouns may be found in several classes
12.
Salt pan (geology)
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Natural salt pans or salt flats are flat expanses of ground covered with salt and other minerals, usually shining white under the Sun. They are found in deserts, and are natural formations, a salt pan forms by evaporation of a water pool such as a lake or pond. This happens in climates where the rate of water exceeds the rate of precipitation. If the water drain into the ground, it remains on the surface until it evaporates. Over thousands of years, the minerals accumulate on the surface and these minerals reflect the Suns rays and often appear as white areas. The crust of salt can conceal a quagmire of mud that can engulf a truck, the Qattara Depression in the eastern Sahara desert contains many such traps which served as strategic barriers during World War II. The Bonneville Salt Flats in Utah, where land speed records have been set, is a well-known salt pan in the arid regions of the western United States. The Etosha pan, in the Etosha National Park in Namibia, is another prominent example of a salt pan, the Salar de Uyuni in Bolivia is the largest salt pan in the world. It contains 50%-70% of the worlds lithium reserves, dry lake Pan Sabkha Salt evaporation pond Salt lake Sink Solonchak Briere, Peter R. Playa, playa lake, sabkha, Proposed definitions for old terms. Lowenstein, Tim K. Lawrence A. Hardie, criteria for the recognition of salt-pan evaporites
13.
Makgadikgadi Pan
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The Makgadikgadi Pan, a salt pan situated in the middle of the dry savanna of north-eastern Botswana, is one of the largest salt flats in the world. The pan is all that remains of the formerly enormous Lake Makgadikgadi, which covered an area larger than Switzerland. The largest individual pan is about 1,900 sq mi, in comparison, Salar de Uyuni in Bolivia is a single salt flat of 4,100 sq mi, rarely has much water, and is generally claimed to be the worlds largest salt pan. A dry salty clay crust most of the year, the pans are seasonally covered with water and grass, the climate is hot and dry but with regular annual rains. The main water source is the Nata River, called Amanzanyama in Zimbabwe, a smaller amount of water is supplied by the Boteti River from the Okavango delta. These salt pans cover 6,200 sq mi in the Kalahari Basin and form the bed of the ancient Lake Makgadikgadi, pastoralists herded grazing livestock here when water was more plentiful earlier in the Holocene. The lowest place in the basin is Sua Pan with an elevation of 2,920 feet, as the ancestral Lake Makgadikgadi shrank, it left relict shorelines, which are most evident in the southwestern part of the basin. As the lake shrank numerous smaller lakes formed with progressively smaller shorelines, the relict shorelines at elevations of 3100 feet and 3018 feet can be seen mostly easily on Gidikwe Ridge, west of the Boteti River. The geologic processes behind the formation of the basin are not well understood and it is conjectured that there was a gentle down-warping of the crust, with accompanying mild tectonics and associated faulting, however, no significant plate boundary faults have been identified. The main axis of the developing graben runs northeast-southwest, kubu Island and Kukome Island are igneous rock islands in the salt flat of Sua pan. Kubu Island lies in the quadrant of Sua Pan, contains a number of baobab trees. The pans themselves are salty desert whose only plant life is a layer of blue-green algae. However the fringes of the pan are salt marshes and further out these are circled by grassland, the prominent baobab trees found in the area function as local landmarks. One of them, named after James Chapman, served as an unofficial post office for 19th-century explorers, the wet season also brings migratory birds such as ducks, geese and great white pelicans. The pan is home of one of two breeding populations of greater flamingos in southern Africa, and only on the Soa pan. The other breeding population is at Etosha, in the Northern part of Namibia, the only birds here in the dry season are ostriches, chestnut-banded plover and Kittlitzs plover. The grasslands on the fringes of the pan are home to such as tortoises, rock monitor, snakes. The regions salt water is home to the cladoceran crustacean Moina belli, another threat is the use of quad bikes and off-road vehicles by tourists, which disturbs breeding colonies of flamingos
14.
Etosha pan
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The Etosha pan is a large endorheic salt pan, forming part of the Kalahari Basin in the north of Namibia. The 120-kilometre-long dry lakebed and its surroundings are protected as Etosha National Park, Etosha, meaning Great White Place is made of a large mineral pan. The area exhibits a white and greenish surface, which spreads over 4,800 km2. The pan developed through tectonic plate activity over about ten million years, around 16,000 years ago, when ice sheets were melting across the land masses of the Northern Hemisphere, a wet climate phase in southern Africa filled Etosha Lake. Today however the Etosha Pan is mostly dry clay mud split into hexagonal shapes as it dries and cracks, and is seldom seen with even a thin sheet of water covering it. It is assumed that the Cunene River fed the lake at that time, now the Ekuma River, the Oshigambo River and the Omurambo Ovambo River are the sole seasonal source of water for the lake. Typically, little water or sediment reaches the dry lake because water seeps into the riverbed along its 250-kilometre course. In the colonial era, the first non-Africans to explore this area were the Europeans Charles John Andersson, the surrounding area is dense mopane woodland which is occupied by herds of elephants on the south side of the lake. Mopane trees are common throughout south-central Africa, and host the mopane worm, which is the form of the moth Gonimbrasia belina. Away from the lake there is grassland that supports grazing animals and this harsh dry land with little vegetation and small amounts of salty water, when it is present at all, supports little wildlife all year round but is used by a large number of migratory birds. The hypersaline pan supports brine shrimp and a number of extremophile micro-organisms tolerant of the saline conditions. In particularly rainy years the Etosha pan becomes a lake approximately 10 cm in depth and becomes a ground for flamingos, which arrive in their thousands. The surrounding savanna is home to a number of mammals that will visit the pan and these include quite large numbers of zebra, blue wildebeest, gemsbok, eland and springbok as well as black rhinoceros, elephants, lions, leopards, and giraffe. The Etosha pan is completely within the park and is designated as a Ramsar wetland of international importance. Ekuma River and Etosha Pan, Namibia, National Council for Science and the Environment, Washington DC Etosha Pan halophytics
15.
Okavango River
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The Okavango River is a river in southwest Africa. It is the fourth-longest river system in southern Africa, running southeastward for 1,600 km and it begins in Angola, where it is known by the Portuguese name Rio Cubango. Further south it forms part of the border between Angola and Namibia, and then flows into Botswana, draining into the Moremi Game Reserve. Before it enters Botswana, the river drops four metres, across the full 1.2 km-width of the river, in a series of known as Popa Falls, visible when the river is low. Discharging to a basin, the Okavango does not have an outlet to the sea. Instead, it empties into a swamp in the Kalahari Desert, part of the rivers flow fills Lake Ngami. Noted for its wildlife, the Okavango area contains Botswanas Moremi Game Reserve, during colder periods in Earths history, a part of the Kalahari was a massive lake, known as Lake Makgadikgadi. In this time, the Okavango would have one of its largest tributaries. Both Namibia and Botswana experience drought and as a result of this, Namibia has built a water canal, measuring about 300 km long, and has proposed a project to build a 250 km pipeline to divert water from the river into Namibia to help relieve the drought. Botswana, however uses the Okavango Delta for both income and a water source. The Department of Water Affairs in Botswana has submitted that 97% of the water in the river is lost through evaporation, so the country cannot afford to lose any extra water. Namibia, in turn, has argued that it will only divert half a percent of the flow. Every wet season, Angola receives three times more rainfall than Botswana, discharging a higher than usual flow into the Okavango, although the summer rains fall in Angola in January, they take a whole month to travel the first 1,000 km of the Okavango River. And then they take a four months to filter through the plants. As a result, the flood is at its biggest sometime between June and August, during Botswana’s dry winter months, and the delta swells to three times its permanent size, attracting animals from miles around and creating one of Africa’s greatest concentrations of wildlife. At its widest point in a big flood year the seasonal swamp stretches to 150 km across from east to west, and one of the factors that leads to the ever changing nature of the Delta is the flatness of the area. In very wet years, a part of the flow may extend along the Magweggana River and enter the Zambezi river
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River delta
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A river delta is a landform that forms from deposition of sediment carried by a river as the flow leaves its mouth and enters slower-moving or standing water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir, River deltas are ecologically important as they provide coastline defense, are home to many species, and can impact drinking water supply. The tidal currents also cannot be too strong, as sediment would wash out into the body faster than the river deposits it. Of course, the river must carry enough sediment to layer into deltas over time, the rivers velocity decreases rapidly, causing it to deposit the majority, if not all, of its load. This alluvium builds up to form the river delta, when the flow enters the standing water, it is no longer confined to its channel and expands in width. This flow expansion results in a decrease in the flow velocity, as a result, sediment drops out of the flow and deposits. Over time, this single channel builds a deltaic lobe, pushing its mouth into the standing water, as the deltaic lobe advances, the gradient of the river channel becomes lower because the river channel is longer but has the same change in elevation. As the slope of the channel decreases, it becomes unstable for two reasons. First, gravity makes the flow in the most direct course down slope. If the river breaches its natural levees, it out onto a new course with a shorter route to the ocean. Second, as its slope gets lower, the amount of stress on the bed decreases, which results in deposition of sediment within the channel. This makes it easier for the river to breach its levees, often when the channel does this, some of its flow remains in the abandoned channel. When these channel-switching events occur, a mature delta develops a distributary network, another way these distributary networks form is from deposition of mouth bars. When this mid-channel bar is deposited at the mouth of a river and this results in additional deposition on the upstream end of the mouth-bar, which splits the river into two distributary channels. A good example of the result of this process is the Wax Lake Delta, in both of these cases, depositional processes force redistribution of deposition from areas of high deposition to areas of low deposition. This results in the smoothing of the shape of the delta as the channels move across its surface. Because the sediment is laid down in fashion, the shape of these deltas approximates a fan. The more often the flow changes course, the shape develops as closer to an ideal fan, the Mississippi and Ural River deltas, with their birds-feet, are examples of rivers that do not avulse often enough to form a symmetrical fan shape
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Namib
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The Namib is a coastal desert in southern Africa. The name Namib is of Nama origin and means vast place, the Namibs northernmost portion, which extends 450 kilometres from the Angola-Namibia border, is known as Moçâmedes Desert, while its southern portion approaches the neighboring Kalahari Desert. From the Atlantic coast eastward, the Namib gradually ascends in elevation, annual precipitation ranges from 2 millimetres in the most arid regions to 200 millimetres at the escarpment, making the Namib the only true desert in southern Africa. Having endured arid or semi-arid conditions for roughly 55–80 million years, the desert geology consists of sand seas near the coast, while gravel plains and scattered mountain outcrops occur further inland. The sand dunes, some of which are 300 metres high, fogs that originate offshore from the collision of the cold Benguela Current and warm air from the Hadley Cell create a fog belt that frequently envelops parts of the desert. Coastal regions can experience more than 180 days of fog a year. While this has proved a hazard to ships—more than a thousand wrecks litter the Skeleton Coast—it is a vital source of moisture for desert life. Owing to its antiquity, the Namib may be home to endemic species than any other desert in the world. Most of the wildlife is arthropods and other small animals that live on little water. Near the coast, the ocean water is rich in fishery resources and supports populations of brown fur seals and shorebirds. Further inland, the Namib-Naukluft National Park, the largest game park in Africa, supports populations of African Bush Elephants, Mountain Zebras, and other large mammals. Although the outer Namib is largely barren of vegetation, lichens and succulents are found in areas, while grasses, shrubs. A few types of trees are able to survive the extremely arid climate. The Namib Desert is one of the 500 distinct physiographic provinces of the South African Platform physiographic division and it occupies an area of around 80,950 km², stretching from the[Usiab River to the town of Lüderitz and from the Atlantic Ocean to the Namib Escarpment. It is about 1,000 miles long north to south. To the south, the Namib borders on the South African Karoo semi-desert, southern Namib comprises a vast dune sea with some of the tallest and most spectacular dunes of the world, ranging in color from pink to vivid orange. In the Sossusvlei area, several dunes exceed 300 meters in height, the complexity and regularity of dune patterns in its dune sea have attracted the attention of geologists for decades, but it remains poorly understood. Moving north from Sossusvlei, the sand gradually gives way to a desert that extends all the way from Sossusvlei to the Swakop river
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Kalahari Basin
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The Kalahari Basin or Kalahari Depression is a large lowland area covering over 2.5 million km² covering most of Botswana and parts of Namibia, South Africa, Angola, Zambia, and Zimbabwe. The outstanding physical feature in the basin, and occupying the centre, is the large Kalahari Desert, the city Windhoek is situated in the Kalahari Basin. Despite its aridity, the Kalahari Basin supports a variety of fauna, the native flora includes acacia trees, African Rosewood and a large number of herbs and grasses. Some of the areas within the Kalahari are seasonal wetlands, such as the Makgadikgadi Pans of Botswana and this area, for example, supports numerous halophilic species and, in the rainy season tens of thousands of flamingos visit these pans. Nxai Pan Nata River Tsodilo Hills C. Michael Hogan Makgadikgadi, Megalithic Portal, ed. A. Burnham Martin Leipold Plants of the Kalahari
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Angola
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Angola /æŋˈɡoʊlə/, officially the Republic of Angola, is a country in Southern Africa. It is the seventh-largest country in Africa and is bordered by Namibia to the south, the Democratic Republic of the Congo to the north, Zambia to the east, and the Atlantic Ocean to west. The exclave province of Cabinda has borders with the Republic of the Congo, the capital and largest city of Angola is Luanda. In the 19th century, European settlers slowly and hesitantly began to themselves in the interior. As a Portuguese colony, Angola did not encompass its present borders until the early 20th century, following resistance by groups such as the Cuamato, the Kwanyama and the Mbunda. Independence was achieved in 1975 under a communist one-party state backed by the Soviet Union, however, the country soon descended into an even lengthier civil war that lasted until 2002. It has since become a relatively stable presidential republic. Angola has vast mineral and petroleum reserves, and its economy is among the fastest growing in the world, Angolas economic growth is highly uneven, with the majority of the nations wealth concentrated in a disproportionately small sector of the population. Angola is a state of the United Nations, OPEC, African Union, the Community of Portuguese Language Countries, the Latin Union. A highly multiethnic country, Angolas 25.8 million people span various tribal groups, customs, Angolan culture reflects centuries of Portuguese rule, namely in the predominance of the Portuguese language and the Catholic Church, combined with diverse indigenous influences. The name Angola comes from the Portuguese colonial name Reino de Angola, the toponym was derived by the Portuguese from the title ngola held by the kings of Ndongo. Ndongo was a kingdom in the highlands, between the Kwanza and Lukala Rivers, nominally tributary to the king of Kongo but which was seeking greater independence during the 16th century, modern Angola was populated predominantly by nomadic Khoi and San prior to the first Bantu migrations. The Khoi and San peoples were neither pastoralists nor cultivators, following a hunter-gatherer lifestyle and they were displaced by Bantu peoples arriving from the north, some of whom likely originated in northwestern Nigeria. Bantu speakers introduced the cultivation of bananas and taro, as well as large herds, to Angolas central highlands. During this time, the Bantu established a number of entities in most of what today comprises Angola. To its south lay the Kingdom of Ndongo, from which the area of the later Portuguese colony was known as Dongo. The region now known as Angola was reached by the Portuguese explorer Diogo Cão in 1484, the year before, the Portuguese had established relations with the Kongo, which stretched at the time from modern Gabon in the north to the Kwanza River in the south. The Portuguese established their primary trading post at Soyo, which is now the northernmost city in Angola apart from the Cabinda exclave
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Zambia
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The capital city is Lusaka, in the south-central part of Zambia. The population is concentrated mainly around Lusaka in the south and the Copperbelt Province to the northwest, originally inhabited by Khoisan peoples, the region was affected by the Bantu expansion of the thirteenth century. After visits by European explorers in the century, Zambia became the British protectorate of Northern Rhodesia towards the end of the nineteenth century. For most of the period, Zambia was governed by an administration appointed from London with the advice of the British South Africa Company. On 24 October 1964, Zambia became independent of the United Kingdom, Kaundas socialist United National Independence Party maintained power from 1964 until 1991. Kaunda played a key role in diplomacy, cooperating closely with the United States in search of solutions to conflicts in Rhodesia, Angola. From 1972 to 1991 Zambia was a one-party state with the UNIP as the legal political party under the motto One Zambia. Kaunda was succeeded by Frederick Chiluba of the social-democratic Movement for Multi-Party Democracy in 1991, beginning a period of social-economic growth, after Mwanawasas death, Rupiah Banda presided as Acting President before being elected President in 2008. Holding office for three years, Banda stepped down after his defeat in the 2011 elections by Patriotic Front party leader Michael Sata. Sata died on 28 October 2014, the second Zambian president to die in office, Guy Scott served briefly as interim president until new elections were held on 20 January 2015, in which Edgar Lungu was elected as the sixth President. In 2010, the World Bank named Zambia one of the worlds fastest economically reformed countries, the Common Market for Eastern and Southern Africa is headquartered in Lusaka. The territory of what is now Zambia was known as Northern Rhodesia from 1911 and it was renamed Zambia at independence in 1964. The new name of Zambia was derived from the Zambezi river, the area of modern Zambia is known to have been inhabited by the Khoisan until around AD300, when migrating Bantu began to settle around these areas. These early hunter-gatherer groups were either annihilated or absorbed by subsequent more organised Bantu groups. Archaeological excavation work on the Zambezi Valley and Kalambo Falls show a succession of human cultures, in particular, ancient camping site tools near the Kalambo Falls have been radiocarbon dated to more than 36,000 year ago. The fossil skull remains of Broken Hill Man, dated between 300,000 and 125,000 years BC, further shows that the area was inhabited by pre-historic man. The early history of tribes of modern-day Zambia can only be gleaned from knowledge passed down by successive generations through word of mouth, in the 12th century, major waves of Bantu-speaking immigrants arrived during the Bantu expansion. Among them, the Tonga people were the first to settle in Zambia and are believed to have come from the east near the big sea, by the late 12th century, more advanced kingdoms and empires had been established in most regions of modern-day Zambia
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Zimbabwe
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Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country located in southern Africa, between the Zambezi and Limpopo Rivers. It is bordered by South Africa to the south, Botswana to the west and southwest, Zambia to the northwest, although it does not border Namibia, less than 200 metres of the Zambezi River separates it from that country. The capital and largest city is Harare, a country of roughly 13 million people, Zimbabwe has 16 official languages, with English, Shona, and Ndebele the most commonly used. Since the 11th century, present-day Zimbabwe has been the site of several organised states and kingdoms as well as a route for migration. The British South Africa Company of Cecil Rhodes first demarcated the present territory during the 1890s, in 1965, the conservative white minority government unilaterally declared independence as Rhodesia. Zimbabwe then rejoined the Commonwealth of Nations—which it withdrew from in 2003 and it is a member of the United Nations, the Southern African Development Community, the African Union, and the Common Market for Eastern and Southern Africa. Robert Mugabe became Prime Minister of Zimbabwe in 1980, when his ZANU-PF party won the following the end of white minority rule. Under Mugabes authoritarian regime, the security apparatus has dominated the country. Mugabe has maintained the revolutionary socialist rhetoric from the Cold War era, the name Zimbabwe stems from a Shona term for Great Zimbabwe, an ancient ruined city in the countrys south-east whose remains are now a protected site. Two different theories address the origin of the word, many sources hold that Zimbabwe derives from dzimba-dza-mabwe, translated from the Karanga dialect of Shona as large houses of stone. The Karanga-speaking Shona people live around Great Zimbabwe in the province of Masvingo. Zimbabwe was formerly known as Southern Rhodesia, Rhodesia, and Zimbabwe Rhodesia, a further alternative, put forward by nationalists in Matabeleland, had been Matopos, referring to the Matopos Hills to the south of Bulawayo. In a 2001 interview, black nationalist Edson Zvobgo recalled that Mawema mentioned the name during a rally, and it caught hold. The black nationalist factions subsequently used the name the during the Second Chimurenga campaigns against the Rhodesian government during the Rhodesian Bush War of 1964-1979, major factions in this camp included the Zimbabwe African National Union, and the Zimbabwe African Peoples Union. Proto-Shona-speaking societies first emerged in the middle Limpopo valley in the 9th century before moving on to the Zimbabwean highlands, the Zimbabwean plateau eventually became the centre of subsequent Shona states, beginning around the 10th century. Around the early 10th century, trade developed with Arab merchants on the Indian Ocean coast, the main archaeological site uses a unique dry stone architecture. The Kingdom of Mapungubwe was the first in a series of sophisticated trade states developed in Zimbabwe by the time of the first European explorers from Portugal and they traded in gold, ivory, and copper for cloth and glass. From about 1300 until 1600, Mapungubwe was eclipsed by the Kingdom of Zimbabwe and this Shona state further refined and expanded upon Mapungubwes stone architecture, which survives to this day at the ruins of the kingdoms capital of Great Zimbabwe
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Sahel
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The Sahel is the ecoclimatic and biogeographic zone of transition in Africa between the Sahara to the north and the Sudanian Savanna to the south. Having a semi-arid climate, it stretches across the south-central latitudes of Northern Africa between the Atlantic Ocean and the Red Sea, the Arabic word sāḥil literally means shore, coast, while the word Sahara is derived from the Arabic word for desert. Together, these names evoke an image of the Sahels vegetation as a coastline on the Saharas ocean of sand, historically, the western part of the Sahel was sometimes known as the Sudan region. This belt was roughly located between the Sahara and the areas of West Africa. It is an ecoregion of semi-arid grasslands, savannas, steppes. The topography of the Sahel is mainly flat, most of the region lies between 200 and 400 meters in elevation, several isolated plateaus and mountain ranges rise from the Sahel, but are designated as separate ecoregions because their flora and fauna are distinct from the surrounding lowlands. Annual rainfall varies from around 100–200 mm in the north of the Sahel to around 600 mm in the south, the Sahel is mostly covered in grassland and savanna, with areas of woodland and shrubland. Grass cover is continuous across the region, dominated by annual grass species such as Cenchrus biflorus, Schoenefeldia gracilis. Species of acacia are the dominant trees, with Acacia tortilis the most common, along with Acacia senegal, other tree species include Commiphora africana, Balanites aegyptiaca, Faidherbia albida, and Boscia senegalensis. In the northern part of the Sahel, areas of shrub, including Panicum turgidum and Aristida sieberana, alternate with areas of grassland. During the long dry season, many lose their leaves. The larger species have greatly reduced in number by over-hunting and competition with livestock. The seasonal wetlands of the Sahel are important for birds moving within Africa. The Sahel has a tropical, hot steppe climate, the climate is typically hot, sunny, dry and somewhat windy all year long. The Sahels climate is similar to, but less extreme than, the Sahel mainly receives a low to a very low amount of precipitation annually. The steppe has a long, prevailing dry season and a short rainy season. The precipitation is extremely irregular, and varies considerably from season to season. Most of the rain falls during only one or two months, while the other months may remain absolutely dry
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Sahara
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The Sahara is the largest hot desert and the third largest desert in the world after Antarctica and the Arctic. Its area of 9,200,000 square kilometres is comparable to the area of the United States. The desert comprises much of North Africa, excluding the fertile region on the Mediterranean Sea coast, the Atlas Mountains of the Maghreb, and the Nile Valley in Egypt and Sudan. It stretches from the Red Sea in the east and the Mediterranean in the north to the Atlantic Ocean in the west, where the landscape gradually changes from desert to coastal plains. To the south, it is bounded by the Sahel, a belt of tropical savanna around the Niger River valley. The Sahara can be divided into several regions including, the western Sahara, the central Ahaggar Mountains, the Tibesti Mountains, the Aïr Mountains, the Ténéré desert, the name Sahara is derived from ṣaḥārā, the plural of the Arabic word for desert. The Sahara covers large parts of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and it covers 9 million square kilometres, amounting to 31% of Africa. If all areas with an annual precipitation of less than 250 mm were included. It is one of three physiographic provinces of the African massive physiographic division. The Sahara is mainly rocky hamada, Ergs form only a minor part, wind or rare rainfall shape the desert features, sand dunes, dune fields, sand seas, stone plateaus, gravel plains, dry valleys, dry lakes, and salt flats. Unusual landforms include the Richat Structure in Mauritania, several deeply dissected mountains, many volcanic, rise from the desert, including the Aïr Mountains, Ahaggar Mountains, Saharan Atlas, Tibesti Mountains, Adrar des Iforas, and the Red Sea hills. The highest peak in the Sahara is Emi Koussi, a volcano in the Tibesti range of northern Chad. The central Sahara is hyperarid, with sparse vegetation, the northern and southern reaches of the desert, along with the highlands, have areas of sparse grassland and desert shrub, with trees and taller shrubs in wadis, where moisture collects. In the central, hyperarid region, there are subdivisions of the great desert, Tanezrouft, the Ténéré, the Libyan Desert, the Eastern Desert. These extremely arid areas often receive no rain for years, the northern limit also corresponds to the 100 mm isohyet of annual precipitation. To the south, the Sahara is bounded by the Sahel, the southern limit of the Sahara is indicated botanically by the southern limit of Cornulaca monacantha, or northern limit of Cenchrus biflorus, a grass typical of the Sahel. According to climatic criteria, the limit of the Sahara corresponds to the 150 mm isohyet of annual precipitation. The Sahara is the worlds largest low-latitude hot desert and this steady descending airflow causes a warming and a drying effect in the upper troposphere
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Thunderstorm
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Thunderstorms occur in association with a type of cloud known as a cumulonimbus. They are usually accompanied by winds, heavy rain, and sometimes snow, sleet, hail, or, in contrast. Thunderstorms may line up in a series or become a rainband, strong or severe thunderstorms, known as supercells, rotate as do cyclones. Thunderstorms result from the upward movement of warm, moist air. As the warm, moist air moves upward, it cools, condenses, as the rising air reaches its dew point temperature, water vapor condenses into water droplets or ice, reducing pressure locally within the thunderstorm cell. Any precipitation falls the long distance through the clouds towards the Earths surface, as the droplets fall, they collide with other droplets and become larger. Thunderstorms can form and develop in any location but most frequently within the mid-latitude. Thunderstorms are responsible for the development and formation of many weather phenomena. Thunderstorms, and the phenomena that occur along them, pose great hazards. Damage that results from thunderstorms is mainly inflicted by downburst winds, large hailstones, stronger thunderstorm cells are capable of producing tornadoes and waterspouts. There are four types of thunderstorms, single-cell, multi-cell cluster, multi-cell lines, supercell thunderstorms are the strongest and the most associated with severe weather phenomena. Mesoscale convective systems formed by vertical wind shear within the tropics and subtropics can be responsible for the development of hurricanes. Dry thunderstorms, with no precipitation, can cause the outbreak of wildfires from the heat generated from the lightning that accompanies them. Several means are used to study thunderstorms, weather radar, weather stations, past civilizations held various myths concerning thunderstorms and their development as late as the 18th century. Beyond the Earths atmosphere, thunderstorms have also observed on the planets of Jupiter, Saturn, Neptune. Warm air has a lower density than air, so warmer air rises upwards. Clouds form as relatively warmer air, carrying moisture, rises within cooler air, the moist air rises, and, as it does so, it cools and some of the water vapor in that rising air condenses. If enough instability is present in the atmosphere, this process will continue long enough for cumulonimbus clouds to form and produce lightning, Meteorological indices such as convective available potential energy and the lifted index can be used to assist in determining potential upward vertical development of clouds
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Anticyclone
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Effects of surface-based anticyclones include clearing skies as well as cooler, drier air. Fog can also form overnight within a region of higher pressure, sir Francis Galton first discovered anticyclones in the 1860s. Preferred areas within a flow pattern in higher levels of the hydrosphere are beneath the western side of troughs. High-pressure systems are referred to as anticyclones. Their circulation is sometimes referred to as cum sole, subtropical high pressure zones form along the descending portion of the Hadley cell circulation. Upper-level high-pressure areas lie over tropical cyclones due to their warm core nature, surface anticyclones form due to downward motion through the troposphere, the atmospheric layer where weather occurs. Preferred areas within a flow pattern in higher levels of the troposphere are beneath the western side of troughs. Because they weaken with height, these systems are cold. Heating of the earth near the equator forces upward motion and convection along the trough or intertropical convergence zone. The divergence over the near-equatorial trough leads to air rising and moving away from the equator aloft, as air moves towards the mid-latitudes, it cools and sinks leading to subsidence near the 30° parallel of both hemispheres. This circulation known as the Hadley cell forms the subtropical ridge, many of the worlds deserts are caused by these climatological high-pressure areas. Because these anticyclones strengthen with height, they are known as warm core ridges, in the absence of rotation, the wind tends to blow from areas of high pressure to areas of low pressure. The stronger the pressure difference between a system and a low-pressure system, the stronger the wind. The coriolis force caused by Earths rotation gives winds within high-pressure systems their clockwise circulation in the northern hemisphere, friction with land slows down the wind flowing out of high-pressure systems and causes wind to flow more outward from the center. High-pressure systems are associated with light winds at the surface and subsidence of air from higher portions of the troposphere. Subsidence will generally warm an air mass by adiabatic heating, thus, high pressure typically brings clear skies. Because no clouds are present to reflect sunlight during the day, there is more incoming solar radiation, at night, the absence of clouds means that outgoing longwave radiation is not blocked, giving cooler diurnal low temperatures in all seasons. If the surface level relative humidity rises towards 100 percent overnight, the movement of continental arctic air masses to lower latitudes produces strong but vertically shallow high-pressure systems
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Intertropical Convergence Zone
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The Intertropical Convergence Zone, known by sailors as the doldrums, is the area encircling the earth near the equator where the northeast and southeast trade winds converge. When it lies near the equator, it is called the near-equatorial trough, where the ITCZ is drawn into and merges with a monsoonal circulation, it is sometimes referred to as a monsoon trough, a usage more common in Australia and parts of Asia. In the seamens speech the zone is referred to as the doldrums because of its weather patterns with stagnant calms. The ITCZ appears as a band of clouds, usually thunderstorms, in the Northern Hemisphere, the trade winds move in a southwestern direction from the northeast, while in the Southern Hemisphere, they move northwestward from the southeast. When the ITCZ is positioned north or south of the equator, for instance, when the ITCZ is situated north of the equator, the southeast trade wind changes to a southwest wind as it crosses the equator. The ITCZ is formed by vertical motion largely appearing as convective activity of thunderstorms driven by heating, which effectively draw air in. The ITCZ is effectively a tracer of the branch of the Hadley cell. The dry descending branch is the horse latitudes, the location of the intertropical convergence zone varies over time with the seasons. Over land, it moves back and forth across the following the suns zenith point. Over the oceans, where the convergence zone is better defined, sometimes, a double ITCZ forms, with one located north and another south of the equator, one of which is usually stronger than the other. When this occurs, a ridge of high pressure forms between the two convergence zones. The South Pacific convergence zone is a reverse-oriented, or west-northwest to east-southeast aligned and it lies just south of the equator during the Southern Hemisphere warm season, but can be more extratropical in nature, especially east of the International Date Line. It is considered the largest and most important piece of the ITCZ, longer term changes in the intertropical convergence zone can result in severe droughts or flooding in nearby areas. In some cases, the ITCZ may become narrow, especially when it moves away from the equator, there appears to be a 15- to 25-day cycle in thunderstorm activity along the ITCZ, which is roughly half the wavelength of the Madden–Julian oscillation. Within the ITCZ the average winds are slight, unlike the north and south of the equator where the trade winds feed. Early sailors named this belt of calm the doldrums because of the inactivity, to find oneself becalmed in this region in a hot and muggy climate could mean death in an era when wind was the only effective way to propel ships across the ocean. Even today leisure and competitive sailors attempt to cross the zone as quickly as possible as the erratic weather and wind patterns may cause unexpected delays. Tropical cyclogenesis depends upon low-level vorticity as one of its six requirements, surges of higher pressure from high latitudes can enhance tropical disturbances along its axis
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Trade winds
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Trade winds also transport African dust westward across the Atlantic Ocean into the Caribbean Sea, as well as portions of southeastern North America. Shallow cumulus clouds are seen within trade wind regimes, and are capped from becoming taller by a trade wind inversion, the weaker the trade winds become, the more rainfall can be expected in the neighboring landmasses. The term trade winds originally derives from the fourteenth century late Middle English word trade. The Portuguese recognized the importance of the winds in navigation in both the north and south Atlantic ocean as early as the 15th century. From West Africa, the Portuguese had to sail away from continental Portugal and they could then turn northeast, to the area around the Azores islands, and finally east to mainland Europe. They also learned that to reach South Africa, they needed to go far out in the ocean, head for Brazil, following the African coast southbound means upwind in the Southern hemisphere. In the Pacific ocean, the wind circulation, which included both the trade wind easterlies and higher-latitude Westerlies, was unknown to Europeans until Andres de Urdanetas voyage in 1565. The captain of a sailing ship seeks a course along which the winds can be expected to blow in the direction of travel, for example, Manila galleons could not sail into the wind at all. Between 1847 and 1849, Matthew Fontaine Maury collected enough information to create wind, as part of the Hadley cell circulation, surface air flows toward the equator while the flow aloft is towards the poles. A low-pressure area of calm, light winds near the equator is known as the doldrums, near-equatorial trough, intertropical front. When located within a region, this zone of low pressure. Around 30° in both hemispheres, air begins to descend toward the surface in subtropical high-pressure belts known as subtropical ridges. The subsident air is dry because as it descends, the temperature increases, but the absolute humidity remains constant. This warm, dry air is known as an air mass. An increase of temperature with height is known as a temperature inversion, when it occurs within a trade wind regime, it is known as a trade wind inversion. The surface air flows from these subtropical high-pressure belts toward the Equator is deflected toward the west in both hemispheres by the Coriolis effect. These winds blow predominantly from the northeast in the Northern Hemisphere, the trade winds of both hemispheres meet at the doldrums. As they blow across tropical regions, air masses heat up over lower latitudes due to direct sunlight
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Great Escarpment, Southern Africa
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And in the west it continues northwards into Namibia and Angola. Different names are applied to different stretches of the Great Escarpment, the Schwarzrand and edge of the Khomas Highland in Namibia, as well as the Serra da Chela in Angola, are also well-known names. About 180 million years ago, a plume under southern Gondwana caused bulging of the continental crust in the area that would later become southern Africa. Within 10 –20 million years rift valleys formed on either side of the central bulge, the stepped steep walls of these rift valleys formed escarpments that surrounded the newly formed Southern African subcontinent. With the widening of the Atlantic, Indian and Southern Oceans, earthquakes rarely occur, and there has been no volcanic or orogenic activity for about 50 million years. This resulted in an almost uninterrupted period of erosion, continuing to the present, a thick layer of marine sediment was consequently deposited onto the continental shelf which surrounds the subcontinent. Thus the altitude of the edge of the eastern escarpments is typically in excess of 2,000 metres and it reaches its highest point where the escarpment forms the Lesotho – KwaZulu-Natal international border. The upliftment of the plateau over the past 20 million years caused the original escarpment to be moved inland through erosion to its present position. The rate of the erosion of the escarpment, in the Drakensberg region is said to average 1.5 metres per 1000 years, or 1.5 millimetres per year. Because of the erosion of the plateau itself, during most of the Mesozoic and Cenozoic eras. The youngest rocks that remain cap the plateau in Lesotho and these rocks form the steep sides of the Great Escarpment in this region, where its upper edge reaches an altitude in excess of 3,000 metres. Thus the rocks found in the Mpumalanga Lowveld below the Mpumalanga portion of the Great Escarpment are more than 3000 million years old. To the south and south-west the rift valleys formed during the break-up of Gondwana, ran. Sediments eroded from these Gondwana mountains buried the Cape Fold Belt, as the escarpment eroded, moving inland, the buried Cape Fold Mountains that had formed 150 million years earlier, were gradually re-exposed. The eastern portion of the Great Escarpment goes as far north as Tzaneen at about the 22° S parallel, from there it veers west to Potgietersrust, where it is known as the Strydpoort Mountains. The lower Limpopo River and Save River drain into the Indian Ocean through what remains of this relict incipient rift valley, the eastern portion of the Great Escarpment within the borders of South Africa is referred to as the Drakensberg, because of the Escarpment’s appearance from below. The Limpopo, Mpumalanga and Lesotho Drakensberg have hard erosion resistant upper surfaces and therefore have a high and rugged appearance, combining steep-sided blocks. The KwaZulu-Natal – Free State Drakensberg escarpment is composed of rocks and therefore has a more rounded
29.
Lake Makgadikgadi
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Lake Makgadikgadi is an ancient lake that existed in what is now the Kalahari Desert in Botswana. It may have covered as much as 80,000 km² and was 30 m deep. The Okavango, Zambezi, and Cuando rivers once all emptied into the lake, approximately 3 million years ago, strong easterly winds brought about the formation of elongated dunes which ran from east to west across the middle of the Kalahari Desert. During wetter times, these dunes channeled the flow of the rivers of the area, the Okavango, Chobe. As the millennia passed, the lake was filled to capacity, about 20,000 years ago, as a result, it began to drain northwards and then eastwards. This caused the middle and lower Zambezi Rivers to connect, resulting in the formation of Victoria Falls, with the water now able to flow out of the basin, Lake Makgadikgadi was able to drain partially and its average level decreased. A drier climatic period followed which caused an increase in evaporation, by about 10,000 years ago the drying of Lake Makgadikgadi was in an advanced stage. Sediment and debris from the Okavango River and windblown sand were gradually filling the lake, the formation of the Gumare fault lowered the land. Today the only remains of Lake Makgadikgadi are the Okavango Delta, the Nxai Pan, Lake Ngami, Lake Xau, the Mababe Depression, in current times this land is desiccated most of the year and is a seasonal wetland in the rainy summer months. C. Michael Hogan Makgadikgadi, The Megalithic Portal, ed. A. Burnham James Owen Lost African Lake Spawned Fish Diversity Beyond Belief, national Geographic News Bushways Safaris article on the Okavango Delta
30.
Acacia
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Acacia, commonly known as the wattles or acacias, is a large genus of shrubs, lianas and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially it comprised a group of plant species native to Africa and Australia, controversy erupted in the early 2000s when it became evident that the genus as it stood was not monophyletic, and that several divergent lineages needed to be placed in separate genera. It turned out that one lineage comprising over 900 species mainly native to Australia was not closely related to the mainly African lineage that contained A. nilotica—the first and this meant that the Australian lineage would need to be renamed. Botanist Les Pedley named this group Racosperma, which was inconsistently adopted and this was officially adopted, but many botanists from Africa and elsewhere disagreed that this was necessary. A number of species have been introduced to parts of the world. The heterogeneous group varies considerably in habit, from mat-like subshrubs to canopy trees in forest, the genus was first described from Africa by C. F. P. von Martius in 1829. Several hundred combinations in Acacia were published by Pedley in 2003, the genus of 981 species, Acacia s. l. in the subfamily Mimosoideae of the pea family Fabaceae is monophyletic. All but 10 of its species are native to Australia, where it constitutes the largest plant genus, following a controversial decision to choose a new type for Acacia in 2005, the Australian component of Acacia s. l. now retains the name Acacia. At the 2011 International Botanical Congress held in Melbourne, the decision to use the name Acacia, other Acacia s. l. taxa continue to be called Acacia by those who choose to consider the entire group as one genus. Australian species of the genus Paraserianthes s. l. are deemed its closest relatives, the origin of wattle may be an Old Teutonic word meaning to weave. From around 700 A. D. watul was used in Old English to refer to the branches and sticks which formed fences, walls. Since about 1810 it refers to the Australian legumes that provide these branches, acacias in Australia probably evolved their fire resistance about 20 million years ago when fossilised charcoal deposits show a large increase, indicating that fire was a factor even then. With no major mountain ranges or rivers to prevent their spread and they began to form dry, open forests with species of the genera Casuarina, Eucalyptus and Callitris. The southernmost species in the genus are Acacia dealbata, Acacia longifolia, Acacia mearnsii and they are present in all terrestrial habitats, including alpine settings, rainforests, woodlands, grasslands, coastal dunes and deserts. In drier woodlands or forest they are an important component of the understory, elsewhere they may be dominant, as in the Brigalow Belt, Myall woodlands and the eremaean Mulga woodlands. Several of its species bear vertically oriented phyllodes, which are green, broadened leaf petioles that function like leaf blades, some phyllodinous species have a colourful aril on the seed. A few species have rather than leaves. Aborigines of Australia have traditionally harvested the seeds of species, to be ground into flour
31.
Cucumis metuliferus
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Health benefits include high in Vitamin A, Beta Carotene and Magnesium. It also has a water content, is good for weight loss and is packed with other vital minerals. Health specialists and nutritionists often call attention to the importance of including adequate amounts of vitamins, zinc, calcium and magnesium are three of the most important minerals essential for good health and just happen to be found in kiwano horned melons. Magnesium aids in the absorption of calcium by the body while zinc actively supports the body’s immune system. Cucumis metuliferus, horned melon or kiwano, also African horned cucumber or melon, jelly melon, hedged gourd, melano, is a vine in the cucumber and melon family. Its fruit has spines, hence the name horned melon. Ripe fruit has orange skin and lime green, jelly-like flesh with a fruity taste. C. metuliferus is native to Sub-Saharan Africa and it is now grown in the United States, Portugal, Italy, Germany, Chile, Australia, and New Zealand. Kiwano is a food plant in Africa. Along with the Gemsbok cucumber and Tsamma it is one of the few sources of water during the dry season in the Kalahari Desert, in northern Zimbabwe it is called gaka or gakachika, and is primarily used as a snack or salad, and rarely for decoration. It can be eaten at any stage of ripening, but when overripened, the fruits taste has been compared to a combination of banana and passionfruit or a combination of banana, cucumber and lime. A small amount of salt or sugar can increase the flavor, some also eat the peel, which is very rich in vitamin C and dietary fiber. The fruit can be used in cooking, but when eaten raw, the fruit, is extremely versatile, it is great in a smoothie, salad, salsa or cocktail Seeding optimum germination temperatures are between 20° and 35°C. Germination is delayed at 12°C, and inhibited at temperatures lower than 12°C or above 35°C, thus, it is recommended to sow in trays and transplant into the field at the two true leaf stage. The best time for transplanting into a field is in the spring when soil. It was found that kiwano is resistant to several root-knot nematodes, some accessions were found to succumb to Fusarium wilt. Resistance to Greenhouse whitefly was reported, kiwano was reported to be resistant to Powdery mildew, however in Israel powdery mildew as well as the Squash mosaic virus attacked kiwano fields and measures had to be taken. Media related to Cucumis metuliferus at Wikimedia Commons Cucumis metuliferus in West African plants – A Photo Guide
32.
Endemism
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The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species that is endemic is precinctive, the word endemic is from New Latin endēmicus, from Greek ενδήμος, endēmos, native. Endēmos is formed of en meaning in, and dēmos meaning the people, the term, precinctive, has been suggested by some scientists, and was first used in botany by MacCaughey in 1917. It is the equivalent of endemism, precinction was perhaps first used by Frank and McCoy. That definition excludes artificial confinement of examples by humans in far-off botanical gardens or zoological parks, physical, climatic, and biological factors can contribute to endemism. The orange-breasted sunbird is found in the fynbos vegetation zone of southwestern South Africa. The glacier bear is found only in limited places in Southeast Alaska, political factors can play a part if a species is protected, or actively hunted, in one jurisdiction but not another. There are two subcategories of endemism, paleoendemism and neoendemism, paleoendemism refers to species that were formerly widespread but are now restricted to a smaller area. Neoendemism refers to species that have arisen, such as through divergence and reproductive isolation or through hybridization. Endemics can easily become endangered or extinct if their restricted habitat changes, particularly—but not only—due to human actions, there were millions of both Bermuda petrels and Bermuda cedars in Bermuda when it was settled at the start of the seventeenth century. By the end of the century, the petrels were thought extinct, cedars, already ravaged by centuries of shipbuilding, were driven nearly to extinction in the twentieth century by the introduction of a parasite. Bermuda petrels and cedars are now rare, as are species endemic to Bermuda
33.
Desert
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A desert is a barren area of land where little precipitation occurs and consequently living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to the processes of denudation, about one third of the land surface of the world is arid or semi-arid. This includes much of the regions where little precipitation occurs. Deserts can be classified by the amount of precipitation falls, by the temperature that prevails. Deserts are formed by weathering processes as large variations in temperature between day and night put strains on the rocks which consequently break in pieces, although rain seldom occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter and the resulting fragments and this picks up particles of sand and dust and wafts them aloft in sand or dust storms. Wind-blown sand grains striking any solid object in their path can abrade the surface, rocks are smoothed down, and the wind sorts sand into uniform deposits. The grains end up as level sheets of sand or are piled high in billowing sand dunes, other deserts are flat, stony plains where all the fine material has been blown away and the surface consists of a mosaic of smooth stones. These areas are known as desert pavements and little further erosion takes place, other desert features include rock outcrops, exposed bedrock and clays once deposited by flowing water. Temporary lakes may form and salt pans may be left when waters evaporate, there may be underground sources of water in the form of springs and seepages from aquifers. Where these are found, oases can occur, plants and animals living in the desert need special adaptations to survive in the harsh environment. Plants tend to be tough and wiry with small or no leaves, water-resistant cuticles, some annual plants germinate, bloom and die in the course of a few weeks after rainfall while other long-lived plants survive for years and have deep root systems able to tap underground moisture. Animals need to cool and find enough food and water to survive. Many are nocturnal and stay in the shade or underground during the heat of the day and they tend to be efficient at conserving water, extracting most of their needs from their food and concentrating their urine. Some animals remain in a state of dormancy for long periods and they then reproduce rapidly while conditions are favorable before returning to dormancy. People have struggled to live in deserts and the surrounding lands for millennia. Nomads have moved their flocks and herds to wherever grazing is available, the cultivation of semi-arid regions encourages erosion of soil and is one of the causes of increased desertification. Many trade routes have been forged across deserts, especially across the Sahara Desert, large numbers of slaves were also taken northwards across the Sahara
34.
Precipitation
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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
35.
Kgalagadi Transfrontier Park
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Kgalagadi Transfrontier Park is a large wildlife preserve and conservation area in southern Africa. Approximately three-quarters of the lies in Botswana and one-quarter in South Africa. In September 2014, more than half of the Botswana portion of the park was sold for gas-fracking, the park is located largely within the southern Kalahari Desert. The terrain consists of red sand dunes, sparse vegetation, occasional trees, the rivers are said to flow only about once per century. However, water flows underground and provides life for grass and camelthorn trees growing in the river beds, the rivers may flow briefly after large thunderstorms. The park has abundant, varied wildlife and it is home to large mammalian predators such as Kalahari lions, Namibian cheetahs, leopards, and hyenas. Migratory herds of large herbivores such as blue wildebeest, springbok, eland, more than 200 species of bird can be found in the park, including vultures and raptors such as eagles, buzzards, and secretary birds. The weather in the Kalahari can reach extremes, january is midsummer in southern Africa and the daytime temperatures are often in excess of 40 °C. Winter nights can be cold with temperatures below freezing. Extreme temperatures of −11 °C and up to 45 °C have been recorded, precipitation is sparse in this desert area. Within the park there are three traditional tourist lodges, called rest camps and these are fully serviced lodges and include amenities such as air conditioning, shops and swimming pools. There are also six wilderness camps in the park, the wilderness camps provide little more than shelter and wash water, visitors must supply their own food, drinking water and firewood. The Kalahari Gemsbok National Park in South Africa was established on 31 July 1931 mainly to protect the game, especially the gemsbok. In 1948 an informal agreement was made between the then Bechuanaland Protectorate and the Union of South Africa to set up a conservation area in the contiguous areas of the two lands. A management plan was drafted, reviewed, and approved in 1997, the parties agreed to cooperate in tourism and share equally in park entrance fees. The boundary between the two parks had no barriers, although it is also the international border between the two countries. This allowed for the movement of animals. On 12 May 2000, President Festus Mogae of Botswana and President Thabo Mbeki of South Africa formally launched Southern Africas first peace park, in October 2002, the governments set aside 580 km² for the use of the native peoples, the Khomani San and Mier communities
36.
ZF Mgcawu District Municipality
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The ZF Mgcawu District Municipality is one of the 5 districts of the Northern Cape province of South Africa. The seat of ZF Mgcawu is Upington, the majority of its 236,783 people speak Afrikaans. ZF Mgcawu District Municipality is named after Upingtons first post-1994 democratically elected mayor, in a previous renaming, from Gordonia, the name Siyanda, meaning we are growing, was used. Election results for Siyanda in the South African general election,2004, population 18 and over,131760 Total votes,75264 Voting % estimate,57. 12% votes as a % of population 18 and over Official website
37.
Ecoregion
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An ecoregion is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than an ecozone. All three of these are less or greater than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, the biodiversity of flora, fauna and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. Three caveats are appropriate for all bio-geographic mapping approaches, firstly, no single bio-geographic framework is optimal for all taxa. Ecoregions reflect the best compromise for as many taxa as possible, secondly, ecoregion boundaries rarely form abrupt edges, rather, ecotones and mosaic habitats bound them. Thirdly, most ecoregions contain habitats that differ from their assigned biome, biogeographic provinces may originate due to various barriers. Some physical, some climatic and some ocean chemical related, the history of the term is somewhat vague as it was used in many contexts, forest classifications, biome classifications, biogeographic classifications, etc. The concept of ecoregion of Bailey gives more importance to ecological criteria, while the WWF concept gives more importance to biogeography, there is significant, but not absolute, spatial correlation among these characteristics, making the delineation of ecoregions an imperfect science. Such transition zones are called ecotones, Ecoregions can be categorized using an algorithmic approach or a holistic, “weight-of-evidence” approach where the importance of various factors may vary. An example of the approach is Robert Bailey’s work for the U. S. The intended purpose of ecoregion delineation may affect the method used, according to WWF, the boundaries of an ecoregion approximate the original extent of the natural communities prior to any major recent disruptions or changes. WWF has identified 867 terrestrial ecoregions, and approximately 450 freshwater ecoregions across the Earth, the use of the term ecoregion is an outgrowth of a surge of interest in ecosystems and their functioning. In particular, there is awareness of issues relating to spatial scale in the study and it is widely recognized that interlinked ecosystems combine to form a whole that is greater than the sum of its parts. The Global 200 is the list of ecoregions identified by WWF as priorities for conservation, Terrestrial ecoregions are land ecoregions, as distinct from freshwater and marine ecoregions. In this context, terrestrial is used to mean of land, WWF ecologists currently divide the land surface of the Earth into 8 major ecozones containing 867 smaller terrestrial ecoregions. The WWF effort is a synthesis of previous efforts to define. Many consider this classification to be decisive, and some propose these as stable borders for bioregional democracy initiatives. The eight terrestrial ecozones follow the major floral and faunal boundaries, identified by botanists and zoologists, ecozone boundaries generally follow continental boundaries, or major barriers to plant and animal distribution, like the Himalayas and the Sahara
38.
World Wide Fund for Nature
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It was formerly named the World Wildlife Fund, which remains its official name in Canada and the United States. It is the worlds largest conservation organization with five million supporters worldwide, working in more than 100 countries, supporting around 1,300 conservation. WWF is a foundation, with 55% of funding from individuals and bequests, 19% from government sources, the groups mission is to stop the degradation of the planet’s natural environment and to build a future in which humans live in harmony with nature. Currently, much of its work concentrates on the conservation of three biomes that contain most of the biodiversity, oceans and coasts, forests. Among other issues, it is concerned with endangered species, sustainable production of commodities. The Conservation Foundation, a precursor to WWF, was founded in 1947 by Fairfield Osborn in New York City in support of capitalism-friendly ecological practices. The advisory council included leading scientists such as Charles Sutherland Elton, G Evelyn Hutchinson, Aldo Leopold, Carl Sauer, and Paul Sears. It supported much of the work cited by Rachel Carsons Silent Spring, including that of John L. George, Roger Hale, Robert Rudd. In 1990, the Conservation Foundation was merged into WWF, after becoming an affiliate of WWF in 1985, the organization now known as the Conservation Foundation in the United States is the former Forest Foundation of DuPage County. The idea for a fund on behalf of endangered animals was initially proposed by Victor Stolan to Sir Julian Huxley in response to articles he published in the British newspaper The Observer, nicholson thought up the name of the organization. WWF was conceived on 29 April 1961, under the name of World Wildlife Fund, godfrey A. Rockefeller also played an important role in its creation, assembling the first staff. For sending experts to danger spots and training, making it all possible that their needs are met before it is too late. WWF has set up offices and operations around the world, the organization also began to run its own conservation projects and campaigns, and by the 1980s started to take a more strategic approach to its conservation activities. In 1986, the changed its name to World Wide Fund for Nature. However, it continued at that time to operate under the name in the United States. We shant save all we should like to, but we shall save a great deal more than if we had never tried, – Sir Peter Scott In 1996, the organization obtained general consultative status from UNESCO. WWFs giant panda logo originated from a panda named Chi Chi that had transferred from Beijing Zoo to London Zoo in 1958. The logo was founded by Young in 1966, the organization also needed an animal that would have an impact in black and white printing
39.
Aristida
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Aristida is a very nearly cosmopolitan genus of plants in the grass family. Aristida is distinguished by having three awns on each lemma of each floret, the genus includes about 300 species found worldwide, often in arid warm regions. This genus is among those colloquially called three-awns wiregrasses, speargrasses and needlegrasses, Aristida stems are ascending to erect, with both basal and cauline leaves. The leaves may be flat or inrolled, and the leaves may be tufted. The inflorescences may be either panicle-like or raceme-like, with spiky branches, the glumes of a spikelet are narrow lanceolate, usually without any awns, while the lemmas are hard, three-veined, and have the three awns near the tip. The awns may be long, in A. purpurea var. longiseta they may be up to 10 cm. They are characteristic of semiarid grassland, the Wiregrass Region of North America is named for A. stricta. Local increases in the abundance of wiregrasses is an indicator of overgrazing. Aristida adscensionis L. Aristida anaclasta Aristida basiramea – fork-tipped three-awn, Aristida beyrichiana Aristida burkei – bohlanya-ba-pere Aristida californica Aristida calycina R. Br. – Shinners three-awn, poverty grass Aristida divaricata Aristida granitica Aristida guayllabambensis Aristida hygrometrica R. Br, Aristida junciformis Aristida longespica – slim-spiked three-awn Aristida longespica var. geniculata – red three-awn Aristida longespica var. longespica Aristida mutabilis Aristida oligantha Michx. – prairie three-awn Aristida pallens Cav, the Jepson Manual - Higher Plants of California, 1234-1235
40.
Eragrostis
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Eragrostis is a large and widespread genus of plants in the grass family, found in many countries on all inhabited continents and many islands. Eragrostis is commonly known as lovegrass or canegrass, the name of the genus is derived from the Greek words ερως, meaning love, and αγρωστις, meaning grass. Lovegrass is commonly used as livestock fodder, the seeds appear to be of high nutritional value for some animals, but they are also very tiny and collecting them for human food is cumbersome and hence uncommon. A notable exception is teff, which is used to make traditional breads on the Horn of Africa, such as Ethiopian injera and it is a crop of commercial importance. E. clelandii and E. tremula are recorded as famine foods in Australia and Chad, other species, such as E. amabilis, are used as ornamental plants. E. cynosuroides is used in the rites in the Hindu temple at Karighatta. Bahia lovegrass is known as a hyperaccumulator of caesium-137 and can be grown to remove the toxic radioactive atoms from the environment. Weeping lovegrass has been planted extensively to prevent soil erosion, seed dispersal is often done by passing animals, the grains hooks latch on to fur or hair, or to clothes. Others are wind or gravity dispersed, several herbivores feed on lovegrass, including invertebrates such as the caterpillars of the Zabulon skipper and vertebrates. The extinct bluebuck was known to graze these grasses, the dense bunches also provide cover for small animals such as the rare Botteris sparrow. Lovegrasses may be important groundcover on oceanic islands like Laysan, where plants are rare. Eragrostis is the genus of the tribe Eragrostideae. Species Formerly included Many species now considered better suited to other genera, interactive Key to Eragrostis of North America
41.
Boscia albitrunca
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Boscia albitrunca, commonly known as the Shepherd tree or Shepherds tree, is a protected tree in South Africa. The species epithet refers to the oftentimes white trunk. It is a tree native to southern and tropical Africa, living in the hot, dry. It is a tree of the Kalahari, bushveld and lowveld. It is one of the most important forage trees in the Kalahari and this tree grows up to 10 m tall but is usually much smaller. It has a prominent, sturdy white trunk frequently with strips of rough, the crown is often browsed by antelope and all grazers that can reach the foliage, resulting in a conspicuous flattened underside or browse-line. The leaves are narrow, oblanceolate, and stiff with veins obscure except for the distinct midrib, the flowers are small, greenish-yellow, star-shaped, and clustered. The fruits, on a stalk, are about 10 mm in diameter and are brittle-skinned with a whitish flesh. A specimen found in the central Kalahari in 1974 had roots extending to 68 m deep, Boscia belongs to the caper family Capparaceae. Pickled capers are made from the buds of European members of this family. Boscia albitrunca is closely related to Boscia foetida subsp, rehmanniana, which has much smaller leaves and velvet-textured fruits. The genus was named for Louis Bosc, a French professor of agriculture who lived through the revolution, list of Southern African indigenous trees Boscia albitrunca. Dressler, S. Schmidt, M. & Zizka, G. Boscia albitrunca, African plants – a Photo Guide
42.
Senegalia mellifera
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Senegalia mellifera is a common thorn tree in Africa. The name mellifera refers to its sweet-smelling blossoms and honey and its lumber turns pitch black when oiled. Common names of the tree include Blackthorn and Swarthaak and it is listed as being not threatened. Senegalia mellifera is found in the dry areas of Africa and the Arabian Peninsula. Senegalia mellifera can occur either as a bush up to seven meters high with more or less a funnel-shaped crown. It can form an impenetrable thickets, in some areas of Africa, it is considered an invasive species as it can expand into and cover large ares of farmland. In Africa, Senegalia mellifera is used as fencing, livestock feed and it flowers are sources of nectar for honey-producing bees. The wood is prized also for fuel and making charcoal and it is widely used in traditional African medicine. The plant contains the psychoactive chemical DMT and this tree is an important food resource for both cattle and wild animals especially in dry areas of Africa. The leaves and young branches are very nutritious, containing a high percentage of protein, the flowers are often eaten by kudu. Common browsers of the tree include elephants, black rhino, giraffe, wikipedia Schwarzdorn-Akazie Acacia mellifera, A Guide to trees Dressler, S. Schmidt, M. & Zizka, G. Acacia mellifera. African plants – a Photo Guide
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