Terrain shapes and bedrock
Within Algeria, in the north, there is an eastern part of the Atlas Mountains, while the rest of the country is occupied by the Sahara. plateaus, sinks and rock masses. The Atlas region, which is 1,000 km long in the east-west direction and 200 km wide, can be divided into three parallel zones, with Tell-Atlas closest to the coast. The mountain range formation took place in tertiary time, and the bedrock consists of Mesozoic and tertiary formations, mainly limestones. The coastal plain is narrow, and the mountains often slope steeply towards the Mediterranean. Among prominent massifs are noted Animal Jurassic (Kabylien) just east of Algiers. To the south, Tell-Atlas turns into a zone of high plateaus and sewerless sinks. Several of these are occupied by salt marshes, chotts, and the area is therefore called the Chott Plateau. The largest are Chott ech-Chergui, Chott el-Hodna and, further south at the border with Tunisia, Chott Melrhir.
According to COUNTRYAAH, the Sahara, which occupies 85% of the country’s surface, is alternately made up of plateaus (200–500 m above sea level), plains with sandy desert (erg), sinks and rock masses. The Plateau du Tademaïet, a limestone block in the north – south direction, separates the two major sand desert areas of Grand Erg Occidental (Great Western Sand Desert) and Grand Erg Oriental (Great Eastern Sand Desert). Several areas are the gravel desert (reg) or the stone and block desert (hammada). In the southwest Erg Chech spreads and in the south-east Ahaggar (2,918 m above sea level) and Tassili n’Ajjer (2,154 m above sea level) rise, blocks of stone surrounded by Paleozoic and Mesozoic sand and limestone quarries. Oases, where the groundwater runs during the day, dried-up river valleys (wadier) and relic groundwater reservoirs are found in most places in the Sahara.
Permanent rivers, on the other hand, exist only in the Atlas area.
The rainfall in Sahara is on average 50 mm per year, but may not disappear for a year or more in a row. Tell-Atlas has a Mediterranean climate with rainfall during the period December – March (400–800 mm per year), while the climate south becomes more continental. Sahara has very high temperatures in summer, but with a daily variation of about 20 °C.
Plant-and animal life
Algeria houses about 3,500 species of seed plants. The vegetation in the far north was originally made up of evergreen forests of mainly cork oak and stone oak, in the mountains also atlas cedar and cypress. As a result of prolonged human activity, nowadays, hard-working macchia and in its places dominate olive groves and other crops. South of the Atlas Mountains, a steppe area with alpha grass (used for papermaking), a wormwood (Artemisia herba-alba) and a mare (Atriplex halimus) take on character plants. However, most parts of the country are occupied by vegetation-poor deserts and semi-deserts (see Sahara.)
In the Atlas Mountains you will find berber monkey, wild boar, genet, golden shawl, berber crown deer, cuvier gazelle and leopard; however, the latter three are almost extinct. Among the birds are the king’s eagle, the miniature bird, the mutton and many Mediterranean species. Carboniferous wake was discovered as late as 1975 in a high-lying coniferous forest area. In the steppe and desert areas, excavating rodents, e.g. desert rats and rats, as well as reptiles. Previously common antelope species in Algeria are the addax antelope, now completely gone, and the dorkas gazelle, which remains in a very small population. Flying chickens, stairs, stone washes and larches make up dominant bird groups.
Algeria had twelve national parks in 2010, the two largest of which are the rock desert areas of Ahaggar and Tassili n’Ajjer in the southeast, the latter with prehistoric rock paintings. In addition, there were eight major nature or hunting reserves.