16
Physical and Natural Environment
The eastern part of Madagascar, an area of approximately 600,000 km², could have been one of the first stopovers for the
Austronesian people who settled in the country. After separating from the African continent, about two hundred million years ago,
Madagascar was free of any human presence. This allowed the development of its biodiversity to become extremely rich in endemic
species. The oldest traces of human occupancy date back to 2500 BC.
Classified as a tropical island, Madagascar’s combination of exposure to trade winds and its topography divides the country into four
distinct regions.
The central highlands, land above 1,000 meters, covers about 70 percent of the territory. The landscape is hilly, and is still covered
with tropical forests on the eastern part, but completely stripped of its vegetation on the western part. A few sacred hills and
plantations of eucalyptus and pine trees from the early 20th century remain. Some riparian forest corridors still exist along some
gulleys due to moisture.
The western part of the country is mainly savannah. The rainy season is relatively short. The low slope from the foothills to the
Mozambique Channel enabled the development of vast fertile alluvial plains. Differential erosion has resulted in cuesta relief on this
sedimentary structure, with a major low-lying clearing at its base, as seen in the region between Bemaraha and Betsiriry.
In the south, rainfall is rare - below 300 mm per year - and there is almost constant sunshine. Combined with the soil type (limestone
plateau and dune formations), the region has a semi-arid atypical landscape. This is an area of xerophytic plants. In order to protect
themselves from strong sunlight and water stress, plants have adapted by minimizing their leaves and replacing them with thorns.
The vast areas of the south are covered year round by zebu cattle in search of better grazing. The transhumance lasts several months
and often covers hundreds of kilometers. It is one of the regions in Madagascar where hunger still causes the death of hundreds or
thousands of people living without a single drop of rain.
Finally, the eastern region is described as an area of tropical rainforest. This is where Ambatovy has established its processing plant.
The three districts that make up this part of the country therefore deserve a more detailed description.
