Total area used for agricultural production is estimated to be 125 million ha or 80% of national land area. The greater part of this area is used for extensive grazing. Not more than 2.5% of the total area is considered to be suitable for arable use (1.7 million ha) and for production of hay (2.0 million ha). Total cropland is put at 1.3 million ha with some 0.8 million ha under crops each year. About 10% of the land surface of Mongolia, equivalent to some 15 million ha are covered by various types of forest with larch (73.6%), cedar (13%), pine (8%), birch (5%) and other species (fir, aspen etc.) dominating in the northern part of the country and saksaul (Haloxylon ammodendron) forests spread in the arid and semi-arid parts of the country, accounting for 28% of the forest cover. Most forests are considered to be critical for watershed protection. Cutting of forest combined with the increasing use of surface water for various economic activities in addition to climatic factors has caused significant reductions in the average flows of many rivers.