The total area of grassland in the world is about 50 million km^2, accounting for 33.5% of the total land area (Lieth, 1975). The permanent grassland used by mankind is 33.04 million km^2, accounting for 25.3% of the ...The total area of grassland in the world is about 50 million km^2, accounting for 33.5% of the total land area (Lieth, 1975). The permanent grassland used by mankind is 33.04 million km^2, accounting for 25.3% of the total land area (FAO,1990). Grassland can provide feed for herbivore and produce high-quality food,clothing,medicines and industrial materials for man.On the other hand,it also plays an important role in the fertility of the soil,the conservation of water, the improvement of the environment and maintaining the ecological balance of the Earth’s surface.展开更多
文摘The total area of grassland in the world is about 50 million km^2, accounting for 33.5% of the total land area (Lieth, 1975). The permanent grassland used by mankind is 33.04 million km^2, accounting for 25.3% of the total land area (FAO,1990). Grassland can provide feed for herbivore and produce high-quality food,clothing,medicines and industrial materials for man.On the other hand,it also plays an important role in the fertility of the soil,the conservation of water, the improvement of the environment and maintaining the ecological balance of the Earth’s surface.