Fluvisols
Fluvisols develop on flat or nearly flat ground, on recent alluvial deposits. These soils are associated with fluvial (river), marine (sea) and lacustine (lake) deposits. These are soils formed due to deposition of eroded materials from highlands. The deposition takes place in depressions, lower valleys and lowlands. Lower regions of rivers like Omo, Awash, Abay and the plains of Akobo and Baro Rivers are home for fluvivsols. Lakes region (main Ethiopian rift) is also characterized by fluvisols. Fluvisols are highly variable, but much prized for intensive agriculture because: they develop on flat ground, deposition sites, they are associated with rivers and ground water, making them important for large-scale irrigation and they are fertile and their fertility is always renewed as a result of deposition of new soil materials.
6. Luvisols
Luvisols develop mainly in areas where pronounced wet and dry seasons occur in alternation. Where leaching is not very high, they are found in association with nitosols. Luvisols have good chemical nutrients and they are among the best agricultural soils in the tropics. So, they are intensively cultivated. However, when luvisols are found on steep slopes (stony) and on flat areas (waterlogged) they are avoided and left for grazing. In Ethiopia, places with luvisols include Lake Tana area, parts of Northern, Central and Eastern Highlands and Southern lowlands. Natural Vegetation of Ethiopia .
Introduction
Natural vegetation refers to a plant cover that develops with little or no human interference. It can also be seen as any original plant cover grown in an area. Its distribution on the surface of the earth is uneven majorly controlled by factors such as climate, soil types, drainage, etc. However, to a large extent, temperature and precipitation affect the spatial distribution and the original plant cover of a region. That is why, more than any other single element, the natural vegetation of an area becomes a very good indicator of the climatic conditions. Natural vegetations are vital for human beings in many ways. Plants can provide shelter, food, source of fuel, pasture and grazing, raw material for industries, source of timber and non-timber products. The other uses include moderating effect on local climate, as home of wild life, medicinal values, minimizing soil erosion etc. The characteristics of Ethiopia's natural vegetation are to a large extent determined by elevation (and temperature) and rainfall. In Ethiopia, since temperature is mostly controlled by elevation, the spatial distribution of natural vegetation in the country is strongly correlated to it. Lowlands due to their low rainfall and high temperature have harsh environment and are characterized by xeromorphic plants (plants which are adapted to drought and high temperatures). Highlands (up to about 3000 m) are cooler than the lowlands and where there is adequate moisture a variety of forests can be seen. Plants whose growth is limited by the low temperature characterize high altitude areas (mostly above 3000 m). Ethiopia possesses an estimated number of 6000 species of higher plants of which 10% are endemic.
