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65-701: This style is characterized by the use of mudbricks and adobe plaster, with large wooden-log support beams that jut out from the wall face for large buildings such as mosques or palaces. These beams also act as scaffolding for reworking, which is done at regular intervals, and involves the local community. Large Neolithic proto-urban walled stone settlements, likely built by Mande-speaking Soninke peoples date from around 1,600-400 BC at Dhar Tichitt and nearby sites in southeastern Mauritania . Other early examples of Sudano-Sahelian style are probably from Dia around 600 BC and Jenné-Jeno around 250 BC, both in Mali , where

130-403: A plaster like paste in broad strokes. This plaster must be reapplied annually. In some cases, brickmakers extended the life of mud bricks by putting fired bricks on top or covering them with stucco . Savanna A savanna or savannah is a mixed woodland - grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that

195-496: A Malian migrant community in traditionally Gur area may build in the style characteristic of their ancestral homeland, while neighbouring Gur buildings are built in the local style. These styles include: The earthen architecture in the Sahel zone region is noticeably different from the building style in the neighboring savannah . The "old Sudanese" cultivators of the savannah built their compounds out of several cone-roofed houses. This

260-466: A binding material such as rice husks or straw . Mudbricks are known from 9000 BCE. From around 5000–4000 BCE, mudbricks evolved into fired bricks to increase strength and durability. Nevertheless, in some warm regions with very little timber available to fuel a kiln , mudbricks continued to be in use. Even today, mudbricks are the standard of vernacular architecture in some warmer regions- mainly in parts of Africa and western Asia . In

325-451: A complete system of wall protection, flat roofing and finishes which in modern English usage is often referred to as adobe style , regardless of the construction method. The Great Mosque of Djenné , in central Mali , is the world's largest mudbrick structure. It, like much of Sahelian architecture, is built with a mudbrick called Banco , a recipe of mud and grain husks, fermented, and either formed into bricks or applied on surfaces as

390-606: A complex society of farmers, craftsmen and merchants with a religious and political upper class. With the expansion of Sahelian kingdoms south to the rural areas in the savannas (inhabited by culturally or ethnically similar groups to those in the Sahel), the Sudano-Sahelian style was reserved for mosques, palaces, the houses of nobility or townsfolk (as is evident in the Gur-Voltaic style), whereas among commonfolk, there

455-438: A continuous tree canopy which would prevent further grass growth. Prior to European settlement aboriginal land use practices, including fire, influenced vegetation and may have maintained and modified savanna flora. It has been suggested by many authors that aboriginal burning created a structurally more open savanna landscape. Aboriginal burning certainly created a habitat mosaic that probably increased biodiversity and changed

520-491: A dramatic reduction in basal area and canopy cover, often leaves a high percentage of woody plants alive either as seedlings too small to be affected or as plants capable of re-sprouting from lignotubers and broken stumps. A population of woody plants equal to half or more of the original number often remains following pulling of eucalypt communities, even if all the trees over 5 metres are uprooted completely. A number of exotic plants species have been introduced to savannas around

585-518: A few courses of fired bricks from their bases up to the splash line to extend the life of the building. In Minoan Crete , at the Knossos site, there is archaeological evidence that sun-dried bricks were used in the Neolithic period (prior to 3400 BCE). Sun dried mudbrick was the most common construction material employed in ancient Egypt during pharaonic times and were made in pretty much

650-804: A high tree density. It is often believed that savannas feature widely spaced, scattered trees. However, in many savannas, tree densities are higher and trees are more regularly spaced than in forests. The South American savanna types cerrado sensu stricto and cerrado dense typically have densities of trees similar to or higher than that found in South American tropical forests, with savanna ranging from 800 to 3300 trees per hectare (trees/ha) and adjacent forests with 800–2000 trees/ha. Similarly Guinean savanna has 129 trees/ha, compared to 103 for riparian forest , while Eastern Australian sclerophyll forests have average tree densities of approximately 100 per hectare , comparable to savannas in

715-402: A means of clearing land. In the 1950s arboricides suitable for stem injection were developed. War-surplus heavy machinery was made available, and these were used for either pushing timber, or for pulling using a chain and ball strung between two machines. These two new methods of timber control, along with the introduction and widespread adoption of several new pasture grasses and legumes promoted

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780-457: A mixture of sand, clay, water and frequently tempered (e.g. chopped straw and chaff branches), and were the most common method/material for constructing earthen buildings throughout the ancient Near East for millennia. Unfired mud-brick is still made throughout the world today, using both modern and traditional methods. The 9000 BCE dwellings of Jericho were constructed from mudbricks, affixed with mud, as were those at numerous sites across

845-560: A particular name called “banco” in West Africa, meaning a wet-mud process similar with the concept of coil pottery. When banco technology continues to be the criterion for dwellings in the savannah area, an alternative method is to use earthen brick consequently with wet mud. The brick is cast into rectangular shape and dried in the sun. One symbol of the Sudanese architecture is the man-made, conical earthen pillars. Being combined with

910-444: A reduction in the need to burn to produce a flush of green growth because legumes retain high nutrient levels throughout the year, and because fires can have a negative impact on legume populations which causes a reluctance to burn. The closed forest types such as broadleaf forests and rainforests are usually not grazed owing to the closed structure precluding grass growth, and hence offering little opportunity for grazing. In contrast

975-469: A resurgence in tree clearing. The 1980s also saw the release of soil-applied arboricides, notably tebuthiuron , that could be utilised without cutting and injecting each individual tree. In many ways "artificial" clearing, particularly pulling, mimics the effects of fire and, in savannas adapted to regeneration after fire as most Queensland savannas are, there is a similar response to that after fire. Tree clearing in many savanna communities, although causing

1040-459: A simplified yet widespread climatic concept. 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. In different parts of North America, the word "savanna" has been used interchangeably with " barrens ", " prairie ", " glade ", "grassland" and " oak opening ". Different authors have defined

1105-555: A special type of Volta Basin religious architecture were also inscribed on the World Heritage list. These mosques were probably originally constructed between the 17th and 19th centuries, as trade routes from the Empire of Mali spread to the south. Mudbrick Mudbrick or mud-brick , also known as unfired brick, is an air-dried brick , made of a mixture of mud (containing loam , clay , sand and water ) mixed with

1170-533: Is Amarna . Mudbrick use increased at the time of Roman influence. In the Ancient Greek world, mudbrick was commonly used for the building of walls, fortifications and citadels, such as the walls of the Citadel of Troy (Troy II). These mudbricks were often made with straw or dried vegetable matter. In areas of Spanish influence, mud-brick construction is called adobe , and developed over time into

1235-402: Is characterized by more elaborate and decorated exterior façades whose compositions emphasize verticality. They have tapering buttresses with cone-shaped summits, mosques have a large tower over the mihrab , and wooden stakes ( toron ) are often embedded in the walls – used for scaffolding but possibly also for some symbolic purpose. The traditional earth building construction technology has

1300-418: Is generally more plain on the exterior of buildings, but is characterized by diverse interior decoration and the much greater use of wood. Mosques often have prayer halls with pillars supporting flat or slightly domed roofs of wood and mud. An exceptional example is the 19th-century Great Mosque of Zaria (present-day Nigeria), which has parabolic arches and a roof of shallow domes. The western or "Sudan" style

1365-483: Is not prominent but that rivers in savanna landscapes erode more by lateral migration . Flooding and associated sheet wash have been proposed as dominant erosion processes in savanna plains. The savannas of tropical America comprise broadleaved trees such as Curatella , Byrsonima , and Bowdichia , with grasses such as Leersia and Paspalum . Bean relative Prosopis is common in the Argentinian savannas. In

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1430-473: Is possible for there to be multiple stable biomes. The annual rainfall ranges from 500 mm (19.69 in) to 1,270 mm (50.00 in) per year, with the precipitation being more common in six or eight months of the year, followed by a period of drought. Savannas may at times be classified as forests. In climatic geomorphology it has been noted that many savannas occur in areas of pediplains and inselbergs . It has been posited that river incision

1495-430: Is said to have owned several mansions, one of which was 66 feet long, 42 feet wide, contained seven rooms, was two stories high, and had a staircase; with the walls and chambers filled with sculpture and painting. A variety of possible influences on this architecture have been suggested. North African and Andalusi architecture to the north may have been one of these, with the existence of square minarets possibly reflecting

1560-419: Is vague and therefore the two can be combined into a single biome as both woodlands and savannas feature open-canopied trees with crowns not usually interlinking (mostly forming 25-60% cover). Over many large tropical areas, the dominant biome (forest, savanna or grassland) can not be predicted only by the climate, as historical events plays also a key role, for example, fire activity. In some areas, indeed, it

1625-660: The Levant over the following millennia. Well-preserved mudbricks from a site at Tel Tsaf, in the Jordan Valley, have been dated to 5200 BCE, though there is no evidence that either site was the first to use the technology. Evidence suggests that the mudbrick composition at Tel Tsaf was stable for at least 500 years, throughout the middle Chalcolithic period. The South Asian inhabitants of Mehrgarh constructed and lived in mud-brick houses between 7000–3300 BCE. Mud bricks were used at more than 15 reported sites attributed to

1690-462: The Mediterranean region were likewise created and maintained by anthropogenic fire. Intentional controlled burns typically create fires confined to the herbaceous layer that do little long term damage to mature trees. This prevents more catastrophic wildfires that could do much more damage. However, these fires either kill or suppress tree seedlings, thus preventing the establishment of

1755-524: The Sankoré Mosque (established in the 14th-15th centuries and rebuilt in the 16th century, with later additions), had a tapering minaret and a prayer hall with rows of arches. The presence of tapering minarets may also reflect cultural contacts with M'zab region to the north, while decoration found at Timbuktu may reflect contacts with Berber communities in what is now Mauritania. More local or indigenous pagan cultures may have also been an influence in

1820-455: The canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. Four savanna forms exist; savanna woodland where trees and shrubs form a light canopy, tree savanna with scattered trees and shrubs, shrub savanna with distributed shrubs, and grass savanna where trees and shrubs are mostly nonexistent. Savannas maintain an open canopy despite

1885-476: The greenhouse effect may result in an alteration of the structure and function of savannas. Some authors have suggested that savannas and grasslands may become even more susceptible to woody plant encroachment as a result of greenhouse induced climate change . However, a recent case described a savanna increasing its range at the expense of forest in response to climate variation, and potential exists for similar rapid, dramatic shifts in vegetation distribution as

1950-749: The prairies in North America and steppes in Eurasia , which feature cold winters, savannas are mostly located in areas having warm to hot climates, such as in Africa, Australia, Thailand, South America and India. The word derives from the Spanish sabana , which is itself a loanword from Taíno , which means "treeless grassland" in the West Indies . The letter b in Spanish, when positioned in

2015-516: The 20th century, the compressed earth block was developed using high pressure as a cheap and eco-friendly alternative to obtain non-fired bricks with more strength than the simpler air-dried mudbricks. The history of mudbrick production and construction in the southern Levant may be dated as far back to the Pre-Pottery Neolithic A (e.g., PPNA Jericho). These sun dried mudbricks, also known as adobe or just mudbrick, were made from

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2080-470: The 3rd millennium BCE in the ancient Indus Valley civilization . In the Mature Harappan phase fired bricks were used. The Mesopotamians used sun-dried bricks in their city construction; typically these bricks were flat on the bottom and curved on the top, called plano-convex mud bricks. Some were formed in a square mould and rounded so that the middle was thicker than the ends. Some walls had

2145-425: The 9th and 14th centuries. The mosque of Kumbi Saleh appears to have gone through multiple construction phases from the 10th century to the early 14th century. At Kumbi Saleh, locals lived in domed-shaped dwellings in the king's section of the city, surrounded by a great enclosure. Traders lived in stone houses in a section which possessed 12 mosques (as described by Al-Bakri ), one centered on Friday prayer . The king

2210-554: The Australian savanna, mammals in the family Macropodidae predominate, such as kangaroos and wallabies, though cattle, horses, camels, donkeys and the Asian water buffalo , among others, have been introduced by humans. It is estimated that less than three percent of savanna ecosystems can be classified as highly intact. Reasons for savanna degradation are manifold, as outlined below. Savannas are subject to regular wildfires and

2275-505: The East African savannas, Acacia , Combretum , baobabs , Borassus , and Euphorbia are a common vegetation genera. Drier savannas there feature spiny shrubs and grasses, such as Andropogon , Hyparrhenia , and Themeda . Wetter savannas include Brachystegia trees and Pennisetum purpureum , and elephant grass type. West African savanna trees include Anogeissus , Combretum , and Strychnos . Indian savannas are mostly cleared, but

2340-527: The Northern Territory, Australia savanna, and 480,000 ha of savanna were being cleared annually in Queensland in the 2000s, primarily to improve pasture production. Substantial savanna areas have been cleared of woody vegetation and much of the area that remains today is vegetation that has been disturbed by either clearing or thinning at some point in the past. Clearing is carried out by

2405-417: The architecture of this region shares a certain style, a wide variety of materials and local styles are evident across this wide geographic range. In the more arid western Sahara and northern Sahel regions, stone predominates as a building material and is often associated with Berber cultures. In the southern Sahel and savannah regions mudbrick and rammed earth are the main material and is now associated with

2470-530: The building itself uniquely, they often project horizontally to the outside like engaged pillars. Being so omnipresent in the vernacular buildings, they can be found singularly or clustered at multiple entrances. As a hallmark of the Sudano Sahelian architecture, they mark the indication of continuity and productivity. The Sudano-Sahelian architectural style itself can be broken down into four smaller sub-styles that are typical of different ethnic groups in

2535-415: The court of the cacique Carlos in present-day Panama . The accounts are inexact, but this is usually placed in present-day Madugandí or at points on the nearby Guna Yala coast opposite Ustupo or on Point Mosquitos . These areas are now either given over to modern cropland or jungle . Many grassy landscapes and mixed communities of trees, shrubs, and grasses were described as savanna before

2600-550: The direction of Ismaila Traoré and with guidance from French engineers. Now the largest earthen (mud) building in sub-Saharan Africa, it served as a model for the new style and for other mosques in the region, including the Grand Mosque of Mopti built by the French administration in 1935. Other 20th-century and more recent mosques in West Africa have tended to replicate a more generic style similar to that of modern Egypt. While

2665-566: The ecosystem appears to be the result of human use of fire. For example, Native Americans created the Pre-Columbian woodlands of North America by periodically burning where fire-resistant plants were the dominant species. Aboriginal burning appears to have been responsible for the widespread occurrence of savanna in tropical Australia and New Guinea , and savannas in India are a result of human fire use. The maquis shrub savannas of

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2730-467: The establishment, growth and survival of plant species and in turn can lead to a change in woodland structure and composition. That being said, impact of grazing animals can be reduced. Looking at Elephant impact on Savannas, the overall impact is reduced in the presence of rainfall and fences. Large areas of Australian and South American savannas have been cleared of trees, and this clearing continues today. For example, land clearing and fracking threaten

2795-579: The first evidence of permanent mudbrick architecture in the region is found, including residences and a large city wall. The first Great Mosque of Djenné (built around 1200 to 1330) in modern Mali, according to traditional accounts, was constructed on the site of an older pre-Islamic palace by the city's king. Starting in the 9th century AD, Muslim merchants came to play a vital role in the western Sahel region through trans-Saharan trade networks. The earliest mosques discovered in sub-Saharan Africa are at Kumbi Saleh (in present-day southern Mauritania),

2860-499: The former capital of the Ghana Empire . Here, a mosque has been discovered which consisted of a courtyard, a prayer hall, and a square minaret , built in dry stone covered in red mud used as plaster. On both the exterior and interior of the mosque, this plaster was painted with floral, geometric, and epigraphic motifs. A similar stone mosque from the same period has been found at Awdaghust . Both mosques are dated generally between

2925-483: The grazing industry in an attempt to increase the quality and quantity of feed available for stock and to improve the management of livestock. The removal of trees from savanna land removes the competition for water from the grasses present, and can lead to a two to fourfold increase in pasture production, as well as improving the quality of the feed available. Since stock carrying capacity is strongly correlated with herbage yield, there can be major financial benefits from

2990-593: The influence of the Great Mosque of Kairouan . As Islamization progressed across the region, more variations developed in mosque architecture, including the adoption of traditional local forms not previously associated with Islamic architecture. Under Songhai influence, minarets took on a more pyramidal appearance and became stepped or tiered on three levels, as exemplified by the tower of the mosque–tomb of Askia al-Hajj Muhammad in Gao (present-day Mali). In Timbuktu ,

3055-419: The later Islamic architecture of the region. During the French colonial occupation of the Sahel, French engineers and architects had a role in popularizing a "Neo-Sudanese" style based on local traditional architecture but emphasizing symmetry and monumentality. The Great Mosque of Djenné, which was previously established in the 14th century but demolished in the early 19th century, was rebuilt in 1906–1907 under

3120-568: The lower limits of savanna tree coverage as 5–10% and upper limits range as 25–80% of an area. Two factors common to all savanna environments are rainfall variations from year to year, and dry season wildfires . In the Americas , e.g. in Belize , Central America , savanna vegetation is similar from Mexico to South America and to the Caribbean . The distinction between woodland and savanna

3185-465: The middle of a word, is pronounced almost like an English v; hence the change of grapheme when transcribed into English. The word originally entered English as the Zauana in a description of the ilands of the kinges of Spayne from 1555. This was equivalent in the orthography of the times to zavana (see history of V ). Peter Martyr reported it as the local name for the plain around Comagre,

3250-425: The middle of the 19th century, when the concept of a tropical savanna climate became established. The Köppen climate classification system was strongly influenced by effects of temperature and precipitation upon tree growth, and oversimplified assumptions resulted in a tropical savanna classification concept which considered it as a "climatic climax" formation. The common usage to describe vegetation now conflicts with

3315-649: The most monumental examples of West African Islamic architecture. In some places, like Timbuktu and Oualata , both building materials are used together, with stone constructions either covered or bound with a mud plaster. In the earthen architecture of the region, scholar Andrew Petersen distinguishes two general styles: a "western" style that may have its roots in Djenné (present-day Mali), and an "eastern" style associated with Hausa architecture that may have its roots in Kano (present-day Nigeria ). The eastern or Hausa style

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3380-469: The open structure of savannas allows the growth of a herbaceous layer and is commonly used for grazing domestic livestock. As a result, much of the world's savannas have undergone change as a result of grazing by sheep, goats and cattle, ranging from changes in pasture composition to woody plant encroachment . The removal of grass by grazing affects the woody plant component of woodland systems in two major ways. Grasses compete with woody plants for water in

3445-438: The potential to significantly alter the structure and composition of savannas worldwide, and have already done so in many areas through a number of processes including altering the fire regime, increasing grazing pressure, competing with native vegetation and occupying previously vacant ecological niches. Other plant species include: white sage, spotted cactus, cotton seed, rosemary. Human induced climate change resulting from

3510-447: The region. The examples used here illustrate the construction of mosques as well as palaces, as the architectural style is concentrated around inland Muslim populations. As with the people, many of these styles cross-pollinate and produce buildings with shared features. Any one of these styles is not exclusive to one particular modern countries borders, but are linked to the ethnicity of its builders or surrounding populations. For example,

3575-431: The removal of trees, such as assisting with grazing management: regions of dense tree and shrub cover harbors predators, leading to increased stock losses, for example, while woody plant cover hinders mustering in both sheep and cattle areas. A number of techniques have been employed to clear or kill woody plants in savannas. Early pastoralists used felling and girdling , the removal of a ring of bark and sapwood , as

3640-585: The reserved ones feature Acacia, Mimosa , and Zizyphus over a grass cover comprising Sehima and Dichanthium . The Australian savanna is abundant with sclerophyllous evergreen vegetation, which include the eucalyptus , as well as Acacia, Bauhinia , Pandanus with grasses such as Heteropogon and kangaroo grass (Themeda). Animals in the African savanna generally include the giraffe, elephant, buffalo, zebra, gnu, hippopotamus, rhinoceros, and antelope, where they rely on grass and/or tree foliage to survive. In

3705-453: The same region. Savannas are also characterised by seasonal water availability, with the majority of rainfall confined to one season. They are associated with several types of biomes , and are frequently in a transitional zone between forest and desert or grassland , though mostly a transition between desert to forest. Savanna covers approximately 20% of the Earth's land area. Unlike

3770-536: The same way for millennia. Mud from some locations required sand, chopped straw or other binders such as animal dung to be mixed in with the mud to increase durability and plasticity. Workers gathered mud from the Nile river and poured it into a pit. Workers then tramped on the mud while straw was added to solidify the mold. The mudbricks were chemically suitable as fertilizer , leading to the destruction of many ancient Egyptian ruins, such as at Edfu . A well-preserved site

3835-515: The soil caused by the hooves of animals and through the erosion effects caused by the removal of protective plant cover. Such effects are most likely to occur on land subjected to repeated and heavy grazing. The effects of overstocking are often worst on soils of low fertility and in low rainfall areas below 500 mm, as most soil nutrients in these areas tend to be concentrated in the surface so any movement of soils can lead to severe degradation. Alteration in soil structure and nutrient levels affects

3900-606: The spread of weeds in savannas by the removal or reduction of the plants which would normally compete with potential weeds and hinder establishment. In addition to this, cattle and horses are implicated in the spread of the seeds of weed species such as prickly acacia ( Acacia nilotica ) and stylo ( Stylosanthes species). Alterations in savanna species composition brought about by grazing can alter ecosystem function, and are exacerbated by overgrazing and poor land management practices. Introduced grazing animals can also affect soil condition through physical compaction and break-up of

3965-519: The structure of woodlands and geographic range of numerous woodland species. It has been suggested by many authors that with the removal or alteration of traditional burning regimes many savannas are being replaced by forest and shrub thickets with little herbaceous layer. The consumption of herbage by introduced grazers in savanna woodlands has led to a reduction in the amount of fuel available for burning and resulted in fewer and cooler fires. The introduction of exotic pasture legumes has also led to

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4030-463: The topsoil and removal by grazing reduces this competitive effect, potentially boosting tree growth. In addition to this effect, the removal of fuel reduces both the intensity and the frequency of fires which may control woody plant species. Grazing animals can have a more direct effect on woody plants by the browsing of palatable woody species. There is evidence that unpalatable woody plants have increased under grazing in savannas. Grazing also promotes

4095-665: The world. Amongst the woody plant species are serious environmental weeds such as Prickly Acacia ( Acacia nilotica ), Rubbervine ( Cryptostegia grandiflora ), Mesquite ( Prosopis spp.), Lantana ( Lantana camara and L. montevidensis ) and Prickly Pear ( Opuntia spp.). A range of herbaceous species have also been introduced to these woodlands, either deliberately or accidentally including Rhodes grass and other Chloris species, Buffel grass ( Cenchrus ciliaris ), Giant rat's tail grass ( Sporobolus pyramidalis ) parthenium ( Parthenium hysterophorus ) and stylos ( Stylosanthes spp.) and other legumes . These introductions have

4160-575: Was a mix between either typically distinct Sudano-Sahelian styles for wealthier families, and older African roundhut styles for rural villages and family compounds. Several outstanding examples of religious and secular Sudano-Sahelian architecture have been awarded UNESCO World Heritage Site status. The historic centers of Djenné , Mali and Agadez , Niger were inscribed on the World Heritage List in 1988 and 2013, respectively. In 2021, 8 small mosques in northern Côte d’Ivoire exemplifying

4225-401: Was primarily an urban building style, associated with centres of trade and wealth, characterised by cubic buildings with terraced roofs comprise the typical style. They lend a characteristic appearance to the close-built villages and cities. Large buildings such as mosques, representative residential and youth houses stand out in the distance. They are landmarks in a flat landscape that point to

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