Savannah

All tropical or rain forests were originally woods located between the Tropic of the Cancer (23° and 27' N) and the Tropic of the Capricorn (23° e 27’ S). This area typically has a mean temperature of approximately 25°C with oscillations of no more than 2-3 degrees and plenty of rainfalls (over 1,500 mm a year). In some forests, the annual rainfall may reach 11,000 mm, even if in most areas it is around 2,500 mm. The best word to describe this forest actually is "rainforest". In some forests it rains little but every day (rainforests or equatorial forests), while in others (in the south-east of Asia) dry and rainy periods alternate (tropical or monsoon forests). Nevertheless, for the sake of clarity, the terms "rainforest" and "tropical forest" will be considered as equivalent.

The savannah in the world
Tropical forests, or rainforests, occupy the so-called inter-tropical area of the planet, that is the area between the Tropic of the Cancer and that of the Tropic of the Capricorn. Large rainforests are mainly in Latin America (Amazonia) where they are called selva, in Africa (Congo, Cameroon, Madagascar, etc.), in the Indo-Malay area (Philippines, Indonesia, etc.) where they are called "jungle" (from the Sanskrit jangala) and in the Australian area (Australia, New Guinea); altogether, they cover 10% of the lands above sea level.

Plants of savannah
The plants of the savannahs are mainly xeromorphic, i.e. adapted to the lack of water, including graminaceous plants, bushes and different species of trees. These adaptations are generally

aimed at preventing water evaporating: falling of leaves during the dry season (such as the acacia) or reduction of foliar surface or development of leathery shells to protect leaves (sclerophyillia), such as the euphorbia. Another form of adaptation to the lack of water is the development of very deep roots to go searching for moisture (such as the Cactaceae) or fleshy stalks or roots to trap water inside (such as the Cactaceae, Euphorbiaceae, Liliaceae or Leguminosae).

Animals of the savannah
A large amount of large-sized herbivores live in the savannah (gnus, zebras, antelopes, giraffes, rhinoceroses and elephants in Africa; deer, elephants and gaurs in India) and in the dry season migrate to more humid areas hundreds of kilometres away. Sometimes herds of different species form. Most of the offspring of the herbivores of the savannah are very precocious: a gnu, for instance, can walk a few minutes after birth. This is because they must not be left behind by their herd, which protects them from predators. The carnivores of the savannah are also social: lions, hyena-dogs, hyenas and jackals hunt in groups according to specific strategies.

African savannah
In Africa, the savannahs are classed according to the arboreal and shrubby species that live there. Generally, the trees are 6 to 12 metres tall, apart from the peculiar African baobab. This tree can be up to 30 metres tall and have a circumference of over 40 metres and a diameter of 10 metres at the base of its trunk. The prevailing baobab in Africa is the Adansonia digitata, which lives to an impressively old age: between 1,000 and perhaps 6,000 years. It is shaped like a bottle and its trunk traps over 120,000 litres of water within its tissues.

Savannahs of Madagascar
Madagascar is an island inhabited by many endemic plants and animals (i.e. existing only in specific areas) because of hundreds of millions of years of seclusion. The northern mountain ridge and the central plateaux act as barriers against the wet winds, thus determining areas with different plants: in the north there is a tropical forest, in the north-west a thick but low and deciduous forest. Finally in the south we found a baobab savannah (seven different species of baobab) that turns into a spiny forest of strange trees with the most bizarre shapes, such as bottle-shaped trees, dwarf baobabs and thick thorny bushes.

American savannahs
In Latin America, the savannahs are called vàrzeas; in areas with rocky basements and little soil, the savannahs are called campo rupestre; in Brazil they are very woody, look like dry forests and are called cerrado. The tierra firme are like the African savannahs even if they are rainier and wetter during the dry season and there are also fewer fires. In the Amazonian region, there are small savannahs, which become larger north of the Amazon. The vàrzeas are, instead, open savannahs which are situated between the Rio Negro and the Xingu and around the Orinoco and which are flooded during the rainy season.

Asian savannahs
In tropical Asia there are monsoons, bringing rain and humidity, so as well as savannahs, there are also "clear" woods and forests, i.e. having deciduous and less luxuriant trees than in rain jungles. In India and Indochina, these areas are inhabited by large herbivores, such as deer, elephants, gaurs and bantengs and large-size predators, such as tigers, leopards, cuons and wolves. In India there are also drier areas: one in the north-west, including part of the Indo basin, the other being the Deccan Plateau. These areas are called sub-desert and include sandy areas where acacias and Zizyphus bushes grow.

The habitat of the savannah favours farming and breeding and this is why it has been remarkably altered. The people living in this biome are mainly farmers who grow cereals and other plants that can resist long dry spells, such as millet, sorghum, barley and wheat, as well as peanuts, cotton, rice and sugarcane, while breeding prevails in drier savannah areas. Farm animals are generally cattle (zebus), sheep, goats and donkeys. Many peoples live in the savannahs: the Nubians in the upper Sudanese Nubia, the Kualngo and the Akan in the Ivory Coast, the Bushmen and the Hottentots in Namibia.

The Masai. The best known people of this habitat are the Masai. The Masai are a number of groups who share the same language and cultural and social similarities and who live scattered between Kenya and Tanzania. They mainly live on sheep-breeding, but also on farming and trade. Breeding provides the staples of the warriors’ diet: they only eat cow milk, meat and blood, while the old and the women also eat butter, legumes and flour. All of them eat a lot of honey while only the old and the women are allowed tobacco. These people have plenty of traditional customs dating back to ancient times: from religious ceremonies to the initiation of young warriors. Men wear their hair long, arranged in thick locks mixed with red ochre and animal fat, while the women, the old and the children must be thoroughly shaved. Another particular customs of the Masai is they change their names at each life stage, from childhood to old age. Among all the inhabitants of the village, one in particular has a superior authority: the oi-boni, a sort of chieftain, who is also a healer and has the power to make prophecies and predictions by throwing stones, inspecting animal entrails, interpreting dreams and consulting oracles. The Masai believe in the existence of two superhuman gods: the red god, who is evil and the bearer of drought, and the black god, who is kind and brings rain. The two gods receive sacrificial offerings and propitiatory rites, especially with grass, that for the Masai has a religious and strongly symbolic value, so much so that if they are fighting against an enemy and want to make peace they offer them grass as a token of peace.

The Bushmen. Another people who used to be numerous and is now reduced to few hundreds of individuals is the Bushmen who live in the Kalahari desert. Their economy is exclusively based on hunting, which is practised by men, and supplemented by roots and seeds, which are collected instead by women and children. The Bushmen’s life style and social organisation are considered as very similar to those of the late Palaeolithic people and this is why they are submitted to in-depth anthropological studies. The Bushmen still use the hunting techniques described in the ancient rock graffiti: the ambush is laid by lying flat on the ground, then poisoned arrows are thrown at the prey. As well as bows, they also use stone-topped clubs, digging canes, stone scraping blades and sometimes spears. Only un-tanned hides are used to make their primitive clothes; the scanty water available is kept in ostrich eggshells. Their homes, which are just windscreens, are erected when they stop, when the hunter has killed his prey. This is eaten at once, just slightly browned on fire, since the Bushmen are not used to preserving their food. Their social structure is quite simple, based on monogamous families. Every family have their hunting territory within the larger but strictly outlined territory of the tribe. The harsh environmental conditions and their nomadic lives impose strict living rules that must have been easier and less strict in the past, as is shown by their rich and lively wealth of myths and legends and by the nature of the Supreme Being, who once used to be good and is now evil “because of the cruel fights he had to endure”. The Bantus first, then the Europeans systematically exterminated the Bushmen. Many of the original groups have disappeared or are reduced to few dozens of individuals so that now the Bushmen are only 10 – 15,000. Today their territory has become a place to look for natural resources, regardless of the impact this may have on the Bushmen. After years of indifference by the African Governments, they are now awakening to the problem of the indigenous minorities who risk disappearing. The community has now become aware of the importance of the Bushmen’s great cultural and artistic heritage, which is regarded as one of the most significant in the history of mankind.

Tourists in the savannah
An important human activity related to the savannah certainly is tourism: the savannah and in particular the wildlife sanctuaries offer the opportunity to observe, film and take pictures of an exotic and particularly fascinating nature, thus becoming an important attraction for tourists and enthusiasts. The safaris, tours within nature reserves, offer the opportunity to capture with one's camera or just with one's eyes wonderful animals in the wild state. Tourism thus becomes an extremely important economical resource for these regions, which are often poor.

A precious biome
Mainly cereals (such as oat and maize), dates, olives and vegetables are grown in the savannah. Breeding includes goats, sheep, horses and cattle. The savannah can be economically useful not only for farming and breeding but also for the natural resources it offers. The baobab for instance is used for different purposes: as a drug to treat a number of diseases, for the light wood used to make music instruments and pirogues. Its fruits can be eaten raw or used to make drinks; its roots are eaten like asparagus. The savannah is also very important for birds, whose survival depends on migrations to avoid the harsh winters of temperate areas.

The origins of the savannah
Before the last glaciations, the Earth certainly looked very different from the way it looks today. In the past, the areas where there are deserts and savannahs now were covered with forests, while an expanse of ice covered the medium and high altitudes. As the climate got drier, the forests slowly disappeared and the savannahs got in. In particular, geological events occurred in the African forests, approximately 7 or 8 million years ago, which can now be explained by plate tectonics and which caused savannahs and man to appear on Earth. The rift valley, that later on would cause the Horn of Africa (Eritrea, Ethiopia, Uganda, etc.) to come off the continent, began to form.

The evolution of hominids
There is plenty of evidence of this evolutionary process. A nearly full skeleton of a female hominid who lived approximately 3.5 million years ago was found in Ethiopia in 1974; scientists called it Lucy. The shape of its spine, leg bones, pelvis and limbs show that Lucy used to walk like we do now. The fossilised footprints of three human beings who had walked through the ash deposits of a recent volcanic eruption were discovered at Laetoli (Tanzania) in 1978. These footprints date back to between 3.6 and 3.8 million years ago and are the most ancient evidence ever found of the existence of two-legged primates.

Today protected areas are formally indicated as “land and/or sea areas specifically dedicated to the protection and preservation of biological diversity and related natural and cultural resources.” According to the classification by the International Union for Conservation of Nature (IUCN), the greatest world organization for the preservation of natural areas, six different general types of protected areas have been devised which reflect different degrees of exposure to human disturbance.

The latter are defined as follows:

• integral nature reserves and uncontaminated areas;
• national parks;
• natural monuments;
• reserves for active management of species, habitats and natural resources;
• protected landscapes and seascapes;
• areas for sustainable management of resources.

Protected areas according to IUCN
Let’s have a closer look at what these definitions mean.

Integral nature reserves and uncontaminated areas. In these areas all species and resources are meticulously protected. The goal is to prevent any possible human interference, banning activities of all sorts. The purpose of these areas, in fact, is to preserve completely biodiversity living within them, guaranteeing total isolation from industrial and anthropized areas. These areas constitute open air ecological laboratories, where the only activity allowed, when holding specific authorization, is indeed scientific study of natural processes.

Natural reserves and sustainability
Modern natural reserves mediate between two different requirements: the protection of the natural heritage and the economic development of local communities. Control over man’s actions in protected areas does no longer serve purely conservative functions; the new-concept reserves aim at promoting those activities that may generate development in marginal areas. Reserves are therefore a new instrument to achieve sustainable development by fulfilling all sustainability requirements…

Rhinoceros hunting
However, in many countries even the establishment of reserves no longer offers good protection to many animals species, because of population increases political and ethnic conflicts (for instance in Mozambique), increasing poverty; there are many people who kill protected animals to sell parts of them to survive. Poachers have caused some species, such as black rhinoceroses, white rhinoceroses and elephants, to disappear. In particular, rhinoceroses are at risk because of their horns, which are much sought-after for medical purposes and to make daggers which in Yemen are symbols of manhood and strength.

Elephants without teeth
Equally important is the problem of elephants, hunted for their ivory tusks. The tusks are the upper incisors, which in old males can reach 2-3 metres long and are used by the pachyderms to strip the bark off trees or dig up roots and in social gatherings are exhibited as a sign of power and used as weapons. Ivory is also used to make jewels and other items, which are much sought-after and sold all over the world. Since the Seventies, the CITES has been successfully protecting Asian elephants and since 1990 African elephants as well.

Vegetal ivory
Vegetal ivory (Phytelephas sp.) is a substance that can be used to replace animal ivory that for years has seriously endangered elephants and threatened them with extinction. Vegetal ivory nuts are extremely hard and can be carved to produce a number of items as well as powerful abrasives and phytochemicals. In addition, this substance, before being hardened, has a creamy texture and is quite tasty. The leaves of this plant are also used to make packaging straw.