Sitting in Houston on day after Thanksgiving watching the events unfolded in Bombay, I felt like the agony was never ending. I was watching ndtv 24X7 through out those sad momemhts.
Then I remembered my association with Bombay.I had lot of misconceptions about this great city before coming here for the first time. It was sheer enormity of this city that amazed me when I dropped in Dadar Railway Station for the first time.
For the next 3 years It was our home.Every other weekend we reach at around 2 or 3 AM in the morning by Hussain Sagar Expressfrom Hyderabad and get down at Dadar and take a taxi to Kandivali from Dadar. Everytime and Everytime we reached home safely. Also, everytime the Taxi driver would give us back the remaining change(chillar) even if it is "charana"(25(NP) or Athana(50 NP).I think this only happens in Bombay.
This whole city is Honest and disciplined. Over the years this city has learned to live with multi linguistic and multi cultured people. The city epitomizes the spirit of India. India is a land of many cultures ,many languages and so is this great city.
When I ask for an address or when I get lost in Mumbai streets I would ask somebody to help me. Each and every time not only I get the correct directions but they would come with me to show me the actual place I was looking for.The city is filled with extremely tolerant, honest, incredible people.
It is an amazing site to see people queuing up to get into a BEST bus or local train. Could anybody imagine this happens in India where people reserve their seats by throwing their hand kercheif(hanky) as soon as they see a bus. This kind of dicipline is shocking specially in India.Queuing up voluntarily is so common in Bombay , may it be a Tatkal Reservation counter in a Railway Station or a in a temple etc. This city has learned to live and understood how to live when 19 million people live together.
My experiences in Bombay is not complete if I do not mention my experiences with Auto Rikshaws. I have very frequently travelled from Kandivali to SEEPZ in Andheri.
The Rikshaws here are amazing. The most special feature of all these autos are their colorful rexine/leather covered seats and big speakers at the back.All these rikshaws are prominently equipped with these audio system. They play beautiful and extremely good songs.Remember all thes rikshaw drivers (atleast most of them) are our brothers from Uttar Pradesh or Bihar who came to Mumbai in search of a living. They are all hard working , innocent , extremely honest people. They would give you back the remaining change(chillar)!!! somethine cannot be expected at all. They are the life line of Mumbai. It is sad to see some politicians are trying to throw them out of Mumbai just because they are not Marathi.
Can anybody describe Bombay without its local trains?, I do not think it is possible.. The local trains make a typical noise when they accelarate I can still here that amazing sound.Something big has to happen if the locals stop running. They are truly lifeline of theis courageous , hard working , honest city. I still remember travelling in last Virar local and get down at Borivali because I cannot simply prepared to get down at Kandivali. I still remember that even after staying in Bombay for years , I did not know which station comes in left and which station comes in right. People line up near the exit of the train left or right depending on the coming station to get down. They exactly know which side the platform comes.Then I used ask people around me "Bhai Kandivali kis taraf aata hai?" then each time I would get an overwhelming response from all of them and they help me in getting down.
Me and my wife used to take a local to go to Matunga Shankarmath every weekend and get down at Matunga station and walk up to the Shankarmath. There is a small bridge like structure which directly connects Matunga station to a place near by the Shankarmath.We used to walk over this bridge and we used to definately buy the Peanuts boiled with salt water. This bridge oversees a railway coach repair factory. It was our most frequent activity to go to Matunga every weekend an there is a small south indian (tamil) restaurant where we used go for Lunch and have a very huge south indian meal.Then after the meal we used to shop around matunga temple where we would get everything like Banana leaves, devotional cassetes/CDS, Jasmine flowers.
We often used to go to see the Abhishekam in the early morning of Lord Rama in a Rama temple near Shankarmath in Matunga.
We used to go to Churchgate just to see the beauty of this great city. We are amazed by the european style of downtown in this great city with big and lavish stone buildings. How many times we went VT station in the night for 10:00 PM for Hussain sagar express. We never had any bad experience in VT. What an amazing railway station it is?? How can somebody harm this great structure.We used reach 1 hour before time and wait for the Hussain Sagar express to pull on to Paltform. We used to go to VT because this outbound train wont stop at Dadar.
Then we used to go to Mahalakshmi to see the mother goddess Lakshmi. We often visited Mumba Devi Temple on whose name this great city has been formed. My father told me that Mumba Devi cut her legs and sat on Mumbai floor(Mumba Devi is in the floor unlike regular Hindu idols where they are erected on a high stand), so she cannot move out of Mumbai. This is the reason for the prosperity of Mumbai as the Mother goddess cannot leave Mumbai and her presence makes the city very rich.
How can I forget the experiences we had when vistied Elephanta Caves in an island near Bombay in the sea. We had taken a small boat to reach the island and climbed a mountain to see elephanta caves on the hill. I cannot really express the beauty and incredible historic importance these caves have. One has to see to believe it.My Father an my mother came with us for this trip.My father is no more in this world but he used to say that There is only one place to see in this world and that is Bombay. He was extremely happy when he first came to Bombay.
we used to go to ISKON temple near Juhu and have wonderful and peaceful experience in this landmark temple. We used to see Amitabh Bachan's residence in Juhu he gives DARSHAN to his fans even today.
How can I forget the Mumbai airport where I took my first flight to Hyderabad from Bombay. Everytime I landed in Bombay in this huge airport my heart used to fill with immense satisfaction.
What about the extremely crowded market outside every railway station where they used to sell everything possible on the earth. Every local station is a small city in its own.
Mumbai is an epitome of Tolerance, Humanity, Humbleness, innocentness, huge , enromousity, Honesty, discipline. Mumbai is the lifeline and spirit of India. Mumbai is beyond a language, creed, color, caste.Mumbai is mine , yours and everybody's.
I am a Mumbaikar, I am proud that Mumbai is in India. I am proud that I lived in Mumbai for once. I want to go back to Mumbai and live there.I want to feel the warmth of Mumbaikars.
I AM A MUMBAIKAR TO THE CORE ALTHOUGH I WAS NOT BORN IN MUMBAI.I CANNOT KEEP MYSELF AWAY FROM THE MOST ENCHANTING, ENDURING, EVERLASTING BEAUTY OF MUMBAI.
I have a sense of acheivement in my life as I lived in Mumbai for once.There is no INDIA without Mumbai.
WE HOPE TO LIVE TO SEE THIS GREAT CITY BECOMING MORE SAFE and KEEP FEEDING PEOPLE FROM ALL OVER INDIA WHO COME HERE FOR THEIR LIVING.
Mumbai is all about people and people of different origins are the lifeline of Mumbai.
I LOVE MUMBAI , I HAVE THE SPIRIT OF MUMBAI IN ME.
Saturday, November 29, 2008
Sunday, November 16, 2008
Angel Falls
Not to be confused with Angel Falls (Maine).
Angel Falls (indigenous name: Churun Merú or Kerepakupai merú) is the world's highest waterfall at 979 m (3,212 ft), with a clear drop of 807 m (2,647 ft). It is located in the Canaima National Park, in the Gran Sabana region of Bolivar State, Venezuela at 5°58′03″N 62°32′08″W / 5.9675, -62.53556Coordinates: 5°58′03″N 62°32′08″W / 5.9675, -62.53556 . The height of the falls is so great that before getting anywhere near the ground, the water is vaporized by the strong winds and turned into mist. The base of the falls feeds into the Kerep river (alternately known as the Rio Gauya) which flows into the Churun River, a tributary of the Carrao River. In the indigenous Pemon language Angel Falls is called Kerepakupai merú meaning "waterfall of the deepest place".
The falls are sometimes referred to as Churun-meru, an error, since that name corresponds to another waterfall in the Canaima National Park. Churun in the Pemon language means "thunder".
Sir Walter Raleigh described what was possibly a tepuy and he is sometimes said to have discovered Angel Falls, but these claims are considered "far-fetched" [2]. They were sighted in 1912 by the Venezuelan explorer Ernesto Sanchez La Cruz, but he did not publicize his discovery. They were not known to the outside world until the American aviator James "Jimmie" Crawford Angel (b. 1899 d. 1956 bp. Springfield, MO)[2] flew over them on 16 November 1933 on a flight while he was searching for a valuable ore bed.
Returning on 9 October 1937, Angel tried to land his Flamingo monoplane "El Rio Caroni" atop Auyan-tepui but the plane was damaged when the wheels sunk into the marshy ground and he and his three companions, including his wife Marie, were forced to descend the tepui on foot. It took them 11 days to make their way back to civilization but news of their adventure spread and the waterfall was named "Angel Falls" in his honour.
Angel Falls (indigenous name: Churun Merú or Kerepakupai merú) is the world's highest waterfall at 979 m (3,212 ft), with a clear drop of 807 m (2,647 ft). It is located in the Canaima National Park, in the Gran Sabana region of Bolivar State, Venezuela at 5°58′03″N 62°32′08″W / 5.9675, -62.53556Coordinates: 5°58′03″N 62°32′08″W / 5.9675, -62.53556 . The height of the falls is so great that before getting anywhere near the ground, the water is vaporized by the strong winds and turned into mist. The base of the falls feeds into the Kerep river (alternately known as the Rio Gauya) which flows into the Churun River, a tributary of the Carrao River. In the indigenous Pemon language Angel Falls is called Kerepakupai merú meaning "waterfall of the deepest place".
The falls are sometimes referred to as Churun-meru, an error, since that name corresponds to another waterfall in the Canaima National Park. Churun in the Pemon language means "thunder".
Sir Walter Raleigh described what was possibly a tepuy and he is sometimes said to have discovered Angel Falls, but these claims are considered "far-fetched" [2]. They were sighted in 1912 by the Venezuelan explorer Ernesto Sanchez La Cruz, but he did not publicize his discovery. They were not known to the outside world until the American aviator James "Jimmie" Crawford Angel (b. 1899 d. 1956 bp. Springfield, MO)[2] flew over them on 16 November 1933 on a flight while he was searching for a valuable ore bed.
Returning on 9 October 1937, Angel tried to land his Flamingo monoplane "El Rio Caroni" atop Auyan-tepui but the plane was damaged when the wheels sunk into the marshy ground and he and his three companions, including his wife Marie, were forced to descend the tepui on foot. It took them 11 days to make their way back to civilization but news of their adventure spread and the waterfall was named "Angel Falls" in his honour.
Amazon
The Amazon River is the second longest river in the world, and the largest in terms of the size of its watershed, the number of tributaries, and the volume of water discharged into the sea. No bridge crosses the river along its entire length.
The Amazon and its tributaries flow through the countries of Peru, Bolivia, Venezuela, Colombia, Ecuador, and Brazil before emptying into the Atlantic Ocean 6, 437 kilometers (4,000 miles) from the Amazon's headwaters high in the Andes mountains of Peru. This huge watershed includes the largest tropical rainforest in the world as well as areas of dry grassland, or savannah.
The rainforest's climate has heavy rainfalls and continuous high temperatures. These forests are so huge that scientists believe they actually help control the world's climate in important ways. Destruction of the forests as settlers clear the land for farming and companies harvest trees for lumber is believed to be contributing to the problem of global warming.
The Amazon is home to a variety of Indian cultures who have a great deal of knowledge about the rich and complex rainforest environment. As settlement brings changes to the forest, these cultural groups are also changing, and the lessons they have gained through thousands of years of living within the rainforest are in danger of being lost. Scientists are trying to learn from the Amazon's native peoples about the amazing variety of rainforest plants and animals before they become extinct. Rainforest plants and animals may hold cures to diseases and provide information and materials valuable to people around the world.
The Amazon and its tributaries flow through the countries of Peru, Bolivia, Venezuela, Colombia, Ecuador, and Brazil before emptying into the Atlantic Ocean 6, 437 kilometers (4,000 miles) from the Amazon's headwaters high in the Andes mountains of Peru. This huge watershed includes the largest tropical rainforest in the world as well as areas of dry grassland, or savannah.
The rainforest's climate has heavy rainfalls and continuous high temperatures. These forests are so huge that scientists believe they actually help control the world's climate in important ways. Destruction of the forests as settlers clear the land for farming and companies harvest trees for lumber is believed to be contributing to the problem of global warming.
The Amazon is home to a variety of Indian cultures who have a great deal of knowledge about the rich and complex rainforest environment. As settlement brings changes to the forest, these cultural groups are also changing, and the lessons they have gained through thousands of years of living within the rainforest are in danger of being lost. Scientists are trying to learn from the Amazon's native peoples about the amazing variety of rainforest plants and animals before they become extinct. Rainforest plants and animals may hold cures to diseases and provide information and materials valuable to people around the world.
Sahara
Sahara desertTable of Contents
1 Introduction
2 Location and General Description
3 Biodiversity Features
4 Current Status
5 Types and Severity of Threats
6 Justification of Ecoregion Delineation
7 Additional Information on this Ecoregion
8 Further Reading
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Content Partner: World Wildlife Fund (other articles)
Article Topics: Biodiversity, Conservation biology and Ecology
This article has been reviewed and approved by the following Topic Editor: Mark McGinley (other articles)
Last Updated: October 12, 2007
--------------------------------------------------------------------------------
Introduction The Sahara is the largest desert in the world and occupies approximately 10 percent of the African Continent. The ecoregion includes the hyper-arid central portion of the Sahara where rainfall is minimal and sporadic. Although species richness and endemism are low, some highly adapted species do survive with notable adaptations. Only a few thousand years ago the Sahara was significantly wetter, and a large mammal fauna resided in this area. Climatic desiccation over the past 5000 years, and intense human hunting over the past 100 years, has obliterated these faunas. Now only rock, sand and sparse vegetation exist over huge areas. The remnant large mammal fauna is highly threatened by over-hunting.
Location and General Description
Libya. (Photograph by SaharaMet)
From the Atlantic Ocean in the west, the greater Sahara stretches across Africa to the Red Sea and down to the highlands of Ethiopia, encompassing an area 9,100,000 square kilometers (km2). This ecoregion covers the central Sahara Desert, between 18° and 30° N, and has an area of 4,619,260 km2. The northern and southern margins of the Sahara, which receive more rainfall and have greater vegetation cover, are described separately.
The surface of the desert ranges from large areas of sand dunes (erg Chech, Raoui), to stone plateaus (hamadas), gravel plains (reg), dry valleys (wadis), and salt flats. Several deeply dissected mountain massifs (Ahaggar, Tassili N'Ajjer, Tibesti, and Aïr) rise from the desert areas, and are delineated as separate ecoregions. Vast underground aquifers that underlie much of the region sometimes penetrate the surface, resulting in oases.
The Sahara is located in a climatic divide. The Intercontinental Convergence Zone moves up from the south, but stops before the center of the Sahara, and consequently hardly carries any rain. Similarly, the winter rainfall of North Africa does not reach far south enough to regularly bring rain to the central Sahara. Consequently, the rainfall, albeit extremely rare, can fall in any season. The annual rainfall is below 25 millimeters (mm), and in the eastern part of the desert it is less than 5 mm per annum. The scarcity of rainfall in this ecoregion is aggravated by its irregularity, as no rain may fall for many years in some areas, followed by a single intense thunderstorm.
The Sahara is one of the hottest regions in the world, with mean annual temperatures exceeding 30°C. In the hottest months, temperatures can rise over 50°C, and temperatures can fall below freezing in the winter. A single daily variation of -0.5°C to 37.5°C has been recorded. The Sahara is also extremely windy. Hot, dust-filled winds create dust devils which can make the temperatures seem even hotter.
The extreme aridity of this area is a relatively recent feature. Much larger areas of the Sahara had adequate water only 5000 to 6000 years ago. It is not clear how much of this ecoregion was covered with vegetation, but in other parts of the Sahara the vegetation was closer to the savanna woodlands of eastern and southern Africa. Currently the ecoregion is in a "hyper arid" phase, with high summer temperatures, lower winter temperatures and rainfall between 0 and 25 mm per annum.
Precambrian rocks are exposed in few places across the Sahara. During the Mesozoic much of North Africa was under water and marine deposits were deposited. The area was uplifted in the Middle Tertiary and has been eroding ever since. Shifting sands and bare rocks cover only about one-fifth of the greater Sahara. More than half of the area comprises soils known as yermosols, with shallow profiles over gravel or pebble beds. These soils have been developing over the past 50 million years.
In terms of the phytogeographical classification of White, the ecoregion is classified as the Sahara regional transition zone. Throughout most of the ecoregion there is very little perennial vegetation. Where it occurs, it is confined to areas where ground water reaches the surface or to areas with runoff. The plants that are present tend to be much more diversified in western Sahara than eastern Sahara, due to the lack of rain to the east. They have strictly Sahara-Arabian affinities, with exceptional adaptations to aridity. Large expanses of ergs and regs will be devoid of any visible plant life for years, but following rainfall, vegetation cover may reach more than 50 percent on sand dunes and 20 percent on the gravel plains.
Biodiversity Features
Sand cat (Felis margarita). (Photograph by Peter Cromer)
The flora of the central Sahara Desert is very poor and estimated to include only 500 species. This is extremely low considering the huge extent of the area. It mainly consists of xerophytes and ephemeral plants (called also locally Acheb), with halophytes in moister areas. The flora has one near endemic family, a number of isolated monotypic genera of both wide and narrow distribution, and perhaps as many as 162 endemic species. The monotypic genera suggest a Tertiary origin with probable extinction of linking forms. Vegetation is very contracted along the wadis and the dayas with Acacia sp, Tamarix sp., and Calotropis procera. Where there is sufficient ground water, hammadas are covered by Anrthirrnum ramosissimuma and Ononis angustissima.
Considering the hyper-arid conditions, the fauna of the central Sahara is richer than is generally believed. Within this ecoregion there are 70 species of mammal, 20 of which are large mammals. There are also 90 species of resident birds, and around 100 species of reptiles. Arthropods are also numerous, especially ants. One of the bird species (Oenanthe monacha) is regarded as endemic to the ecoregion, and there is one strictly endemic currently undescribed worm snake (Leptotyphlops sp nov. "L"). However, given the vast size of the ecoregion, the number of endemic species is very small.
In the past the critically threatened addax (Addax nasomaculatus) would probably have occurred in this ecoregion, but this species is likely to be extirpated. Small numbers of scimiter-horned oryx (Oryx dammah, EX) may have also occurred in the past. Other desert antelopes may still be found in small numbers, such as slender-horned gazelle (Gazella leptoceros, EN), dama gazelle (Gazella dama, EN) and the red-fronted gazelle (Gazella rufifrons, VU).
The plants and animals of the Sahara are more threatened by desiccation than the fauna and flora in other areas. Plant leaves may dry out totally and then recover; animals may loose 30-60% of their body mass and are still able to recover. Many of the animals get their water only through metabolic processes. These kinds of adaptations have allowed them to survive in such an inhospitable environment.
Current Status The Sahara is a vast area of largely undisturbed habitat, principally sand and rock, but with small areas of permanent vegetation. The most degradation is found where there is water (oases, etc). Here, habitats may be heavily altered by human activities. Previously existing tree cover has often been removed for fuel and fodder by nomadic pastoralists and traders.
The Sahara desert is not well protected. Yet, this may be due to the low population and impracticality of defining borders over this vast area. Fewer than 2 million inhabitants reside throughout the entire Sahara Desert. The majority are nomads, predominantly the Tuareg, Tibbu, and Moors. They survive by nomadic pastoralism, hunting, and trading. Most of these people are found in the desert margins and they do not often spend much time in the central hyper-arid portion.
Only one area is recorded in the Sahara: Zellaf Nature Reserve in Libya (1,000 km2).
Types and Severity of Threats
Sahara Desert, Algeria. (Photograph by Jeanne Tabachnick)
The ephemeral habitats of the Sahara, which only develop following rainfall, are not highly threatened by human activities. The more persistent pressures are found in areas of permanent water (oases), or in areas where water comes close to the surface. Here, the local pressure on natural resources can be intense. There is also an intense pressure on any remaining populations of large mammals adapted to desert conditions. The populations of all such species have been greatly reduced by hunting for food, and also through hunting for sport and recreation. The addax (Addax nsaomaculatus) is now critically threatened with extinction, mainly due to intense over-hunting, and most of the other desert-adapted antelopes that may still occur in the ecoregion are endangered.
In recent years development projects have started in the deserts of Algeria and Tunisia using irrigated water pumped from underground aquifers. These schemes often lead to soil degradation and salinization because of "drainage" problems.
Justification of Ecoregion Delineation
The borders for this ecoregion follow "desert dunes with perennial vegetation" and "absolute desert," mapped by White, and correspond approximately to the region with less than 25 mm of mean annual rainfall. The northern and southern margins of the Sahara, which receive more rainfall and have greater vegetation cover, are delineated separately as the North and South Saharan Steppe and Woodlands. The ecoregion also forms a majority of the Sahara biogeographic province of Udvardy.
Additional Information on this EcoregionFor a shorter summary of this entry, see the WWF WildWorld profile of this ecoregion.
To see the species that live in this ecoregion, including images and threat levels, see the WWF Wildfinder description of this ecoregion.
World Wildlife Fund Homepage
Further Reading
Climap 1976. The surface of the ice age earth. Science 191: 1131-1144.
Cloudsley-Thompson, J.L. 1984. Sahara Desert. Perhamon Press, Oxford. ISBN: 0080288693
Le Houérou, H.N. 1990. Recherches écoclimatique et biogéographique sur les zones arides de L'Afrique du Nord. CEPE/CNRS, Montpellier, 600pp.
Le Houérou, H.N. 1991. Outline of a Biological History of the Sahara. Pages 146-174 in J.A. McNeely and V.M. Neronov, editors. Mammals in the Palaearctic Desert: status and trends in the Sahara-Gobian region. The Russian Acedemy of Sciences, and the Russian Committee for the UNESCO programme on Man and the Biosphere (MAB).
Ozenda, P. 1983. Flore du Sahara. Pages 21-32 en Editions du Centre National de la Recherche Scientifique (CNRS), Paris. ISBN: 2222002923
Quézel, P. 1965. La vegetation du Sahara, du Tchad a la Mauritanie. Fisher Verlag, Stuttgart. 333pp.
Williams, M.A.J. and H. Faure, editors. 1980. The Sahara and the Nile. Balkema, Rotterdam. ISBN: 9061910196
White, F. 1983. The vegetation of Africa: a descriptive memoir to accompany the UNESCO/AETFAT/UNSO vegetation map of Africa. UNESCO, Paris, France. ISBN: 9231019554
WWF and IUCN. 1994. Centres of plant diversity. A guide and strategy for their conservation. Volume 1. Europe, Africa, South West Asia and the Middle East. IUCN Publications Unit, Cambridge, U.K. ISBN: 283170197X
Zahoran, M.A. and A.J. Willis. 1992. The Vegetation of Egypt. Chapman and Hall, London. ISBN: 0412315106
Disclaimer: This article is taken wholly from, or contains information that was originally published by, the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.
1 Introduction
2 Location and General Description
3 Biodiversity Features
4 Current Status
5 Types and Severity of Threats
6 Justification of Ecoregion Delineation
7 Additional Information on this Ecoregion
8 Further Reading
--------------------------------------------------------------------------------
Content Partner: World Wildlife Fund (other articles)
Article Topics: Biodiversity, Conservation biology and Ecology
This article has been reviewed and approved by the following Topic Editor: Mark McGinley (other articles)
Last Updated: October 12, 2007
--------------------------------------------------------------------------------
Introduction The Sahara is the largest desert in the world and occupies approximately 10 percent of the African Continent. The ecoregion includes the hyper-arid central portion of the Sahara where rainfall is minimal and sporadic. Although species richness and endemism are low, some highly adapted species do survive with notable adaptations. Only a few thousand years ago the Sahara was significantly wetter, and a large mammal fauna resided in this area. Climatic desiccation over the past 5000 years, and intense human hunting over the past 100 years, has obliterated these faunas. Now only rock, sand and sparse vegetation exist over huge areas. The remnant large mammal fauna is highly threatened by over-hunting.
Location and General Description
Libya. (Photograph by SaharaMet)
From the Atlantic Ocean in the west, the greater Sahara stretches across Africa to the Red Sea and down to the highlands of Ethiopia, encompassing an area 9,100,000 square kilometers (km2). This ecoregion covers the central Sahara Desert, between 18° and 30° N, and has an area of 4,619,260 km2. The northern and southern margins of the Sahara, which receive more rainfall and have greater vegetation cover, are described separately.
The surface of the desert ranges from large areas of sand dunes (erg Chech, Raoui), to stone plateaus (hamadas), gravel plains (reg), dry valleys (wadis), and salt flats. Several deeply dissected mountain massifs (Ahaggar, Tassili N'Ajjer, Tibesti, and Aïr) rise from the desert areas, and are delineated as separate ecoregions. Vast underground aquifers that underlie much of the region sometimes penetrate the surface, resulting in oases.
The Sahara is located in a climatic divide. The Intercontinental Convergence Zone moves up from the south, but stops before the center of the Sahara, and consequently hardly carries any rain. Similarly, the winter rainfall of North Africa does not reach far south enough to regularly bring rain to the central Sahara. Consequently, the rainfall, albeit extremely rare, can fall in any season. The annual rainfall is below 25 millimeters (mm), and in the eastern part of the desert it is less than 5 mm per annum. The scarcity of rainfall in this ecoregion is aggravated by its irregularity, as no rain may fall for many years in some areas, followed by a single intense thunderstorm.
The Sahara is one of the hottest regions in the world, with mean annual temperatures exceeding 30°C. In the hottest months, temperatures can rise over 50°C, and temperatures can fall below freezing in the winter. A single daily variation of -0.5°C to 37.5°C has been recorded. The Sahara is also extremely windy. Hot, dust-filled winds create dust devils which can make the temperatures seem even hotter.
The extreme aridity of this area is a relatively recent feature. Much larger areas of the Sahara had adequate water only 5000 to 6000 years ago. It is not clear how much of this ecoregion was covered with vegetation, but in other parts of the Sahara the vegetation was closer to the savanna woodlands of eastern and southern Africa. Currently the ecoregion is in a "hyper arid" phase, with high summer temperatures, lower winter temperatures and rainfall between 0 and 25 mm per annum.
Precambrian rocks are exposed in few places across the Sahara. During the Mesozoic much of North Africa was under water and marine deposits were deposited. The area was uplifted in the Middle Tertiary and has been eroding ever since. Shifting sands and bare rocks cover only about one-fifth of the greater Sahara. More than half of the area comprises soils known as yermosols, with shallow profiles over gravel or pebble beds. These soils have been developing over the past 50 million years.
In terms of the phytogeographical classification of White, the ecoregion is classified as the Sahara regional transition zone. Throughout most of the ecoregion there is very little perennial vegetation. Where it occurs, it is confined to areas where ground water reaches the surface or to areas with runoff. The plants that are present tend to be much more diversified in western Sahara than eastern Sahara, due to the lack of rain to the east. They have strictly Sahara-Arabian affinities, with exceptional adaptations to aridity. Large expanses of ergs and regs will be devoid of any visible plant life for years, but following rainfall, vegetation cover may reach more than 50 percent on sand dunes and 20 percent on the gravel plains.
Biodiversity Features
Sand cat (Felis margarita). (Photograph by Peter Cromer)
The flora of the central Sahara Desert is very poor and estimated to include only 500 species. This is extremely low considering the huge extent of the area. It mainly consists of xerophytes and ephemeral plants (called also locally Acheb), with halophytes in moister areas. The flora has one near endemic family, a number of isolated monotypic genera of both wide and narrow distribution, and perhaps as many as 162 endemic species. The monotypic genera suggest a Tertiary origin with probable extinction of linking forms. Vegetation is very contracted along the wadis and the dayas with Acacia sp, Tamarix sp., and Calotropis procera. Where there is sufficient ground water, hammadas are covered by Anrthirrnum ramosissimuma and Ononis angustissima.
Considering the hyper-arid conditions, the fauna of the central Sahara is richer than is generally believed. Within this ecoregion there are 70 species of mammal, 20 of which are large mammals. There are also 90 species of resident birds, and around 100 species of reptiles. Arthropods are also numerous, especially ants. One of the bird species (Oenanthe monacha) is regarded as endemic to the ecoregion, and there is one strictly endemic currently undescribed worm snake (Leptotyphlops sp nov. "L"). However, given the vast size of the ecoregion, the number of endemic species is very small.
In the past the critically threatened addax (Addax nasomaculatus) would probably have occurred in this ecoregion, but this species is likely to be extirpated. Small numbers of scimiter-horned oryx (Oryx dammah, EX) may have also occurred in the past. Other desert antelopes may still be found in small numbers, such as slender-horned gazelle (Gazella leptoceros, EN), dama gazelle (Gazella dama, EN) and the red-fronted gazelle (Gazella rufifrons, VU).
The plants and animals of the Sahara are more threatened by desiccation than the fauna and flora in other areas. Plant leaves may dry out totally and then recover; animals may loose 30-60% of their body mass and are still able to recover. Many of the animals get their water only through metabolic processes. These kinds of adaptations have allowed them to survive in such an inhospitable environment.
Current Status The Sahara is a vast area of largely undisturbed habitat, principally sand and rock, but with small areas of permanent vegetation. The most degradation is found where there is water (oases, etc). Here, habitats may be heavily altered by human activities. Previously existing tree cover has often been removed for fuel and fodder by nomadic pastoralists and traders.
The Sahara desert is not well protected. Yet, this may be due to the low population and impracticality of defining borders over this vast area. Fewer than 2 million inhabitants reside throughout the entire Sahara Desert. The majority are nomads, predominantly the Tuareg, Tibbu, and Moors. They survive by nomadic pastoralism, hunting, and trading. Most of these people are found in the desert margins and they do not often spend much time in the central hyper-arid portion.
Only one area is recorded in the Sahara: Zellaf Nature Reserve in Libya (1,000 km2).
Types and Severity of Threats
Sahara Desert, Algeria. (Photograph by Jeanne Tabachnick)
The ephemeral habitats of the Sahara, which only develop following rainfall, are not highly threatened by human activities. The more persistent pressures are found in areas of permanent water (oases), or in areas where water comes close to the surface. Here, the local pressure on natural resources can be intense. There is also an intense pressure on any remaining populations of large mammals adapted to desert conditions. The populations of all such species have been greatly reduced by hunting for food, and also through hunting for sport and recreation. The addax (Addax nsaomaculatus) is now critically threatened with extinction, mainly due to intense over-hunting, and most of the other desert-adapted antelopes that may still occur in the ecoregion are endangered.
In recent years development projects have started in the deserts of Algeria and Tunisia using irrigated water pumped from underground aquifers. These schemes often lead to soil degradation and salinization because of "drainage" problems.
Justification of Ecoregion Delineation
The borders for this ecoregion follow "desert dunes with perennial vegetation" and "absolute desert," mapped by White, and correspond approximately to the region with less than 25 mm of mean annual rainfall. The northern and southern margins of the Sahara, which receive more rainfall and have greater vegetation cover, are delineated separately as the North and South Saharan Steppe and Woodlands. The ecoregion also forms a majority of the Sahara biogeographic province of Udvardy.
Additional Information on this EcoregionFor a shorter summary of this entry, see the WWF WildWorld profile of this ecoregion.
To see the species that live in this ecoregion, including images and threat levels, see the WWF Wildfinder description of this ecoregion.
World Wildlife Fund Homepage
Further Reading
Climap 1976. The surface of the ice age earth. Science 191: 1131-1144.
Cloudsley-Thompson, J.L. 1984. Sahara Desert. Perhamon Press, Oxford. ISBN: 0080288693
Le Houérou, H.N. 1990. Recherches écoclimatique et biogéographique sur les zones arides de L'Afrique du Nord. CEPE/CNRS, Montpellier, 600pp.
Le Houérou, H.N. 1991. Outline of a Biological History of the Sahara. Pages 146-174 in J.A. McNeely and V.M. Neronov, editors. Mammals in the Palaearctic Desert: status and trends in the Sahara-Gobian region. The Russian Acedemy of Sciences, and the Russian Committee for the UNESCO programme on Man and the Biosphere (MAB).
Ozenda, P. 1983. Flore du Sahara. Pages 21-32 en Editions du Centre National de la Recherche Scientifique (CNRS), Paris. ISBN: 2222002923
Quézel, P. 1965. La vegetation du Sahara, du Tchad a la Mauritanie. Fisher Verlag, Stuttgart. 333pp.
Williams, M.A.J. and H. Faure, editors. 1980. The Sahara and the Nile. Balkema, Rotterdam. ISBN: 9061910196
White, F. 1983. The vegetation of Africa: a descriptive memoir to accompany the UNESCO/AETFAT/UNSO vegetation map of Africa. UNESCO, Paris, France. ISBN: 9231019554
WWF and IUCN. 1994. Centres of plant diversity. A guide and strategy for their conservation. Volume 1. Europe, Africa, South West Asia and the Middle East. IUCN Publications Unit, Cambridge, U.K. ISBN: 283170197X
Zahoran, M.A. and A.J. Willis. 1992. The Vegetation of Egypt. Chapman and Hall, London. ISBN: 0412315106
Disclaimer: This article is taken wholly from, or contains information that was originally published by, the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.
Thursday, November 6, 2008
Heartwalk-2008 was fun...and for great cause...
I participated last year , so I was looking forward for this year too.. It was a grogeous day , Lots of people showed up.. Memorial Hermann was the biggest sponsor, they seems have raised 1 MN usd.That much money in this economy is really amazing... anyways it was a great experience for a great cause...
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