Although water is available in quantities adequate for irrigation and it has the amount of fall necessary for hydroelectric power production, terrain and seasonal factors are such that major capital investment would be required for both irrigation and power projects. Snow stabilizes drainage of the higher northern and eastern mountains but, unfortunately, the only major snow accumulations are in the Drin basin, influencing only the one river system. NATURAL RESOURCES Soils Soil resources are small. Arable land figures notwithstanding, good agricultural land amounts to only about 5 percent of the country's area. Soils over limestone are thin or altogether lacking. Serpentine rock erodes slowly and produces clays of little agricultural value. The softer rocks of the intermediate mountains crumble easily into course and infertile sands and gravels that take many years to acquire humus. The alluvial soil of the lowland plains, therefore, tends to be sterile in addition to receiving its precipitation seasonally and being poorly drained. There is little land along the narrow valley floors. The best soils, those within the inland basins, are excellent. The narrow margin of slightly elevated land between the coastal plains and the mountains also provides excellent arable fields. Vegetation Western sources have estimated that, in 1969, 11 percent of the land area was arable, of which nearly one-half was in use as vineyards and olive groves. Forests covered just over one-third of the land, and pastures just under one-third. About 22 percent of the land was unproductive, but one-half of the unproductive areas had a potential for development. Albanian government pronouncements have stated that about 20 percent of the land was arable in 1968 and that this figure would be increased to 22 percent in 1970. The discrepancies in land use statistics arise from varying interpretations as to the amount of pastureland that is arable. Much that Albanian sources have claimed as newly arable almost certainly is marginally so. Dependence upon corn as the primary staple crop in much of the country and limited amounts of arable land tended, until about 1950, to prevent proper crop rotation. The government is attempting to introduce more scientific agricultural practices and has claimed improved crop yields. Although the amount of land that can be cultivated for the production of foodstuffs is meager, the remoteness of the interior has allowed natural flora to exist over fairly extensive areas with little disturbance. A large variety of species flourishes, and an unusual number of them are found in that vicinity only. Of some 2,300 seed-bearing plants, over 300 appear in the Balkans alone, and more than 50 occur only in Albania.