![]() ![]() Īround 5 million years ago during the Late Miocene in the New World and the Pliocene in the Old World, the first true grasslands occurred. The appearance of mountains in the western United States during the Miocene and Pliocene epochs, a period of some 25 million years, created a continental climate favourable to the evolution of grasslands. They became widespread toward the end of the Cretaceous period, and coprolites of fossilized dinosaur feces have been found containing phytoliths of a variety of grasses that include grasses that are related to modern rice and bamboo. The graminoids are among the most versatile life forms. There are many different types of semi-natural grasslands, e.g. ".without the use of pesticides or fertilisers in modern time.". ![]() ".have been formed over the course of centuries through extensive grazing and mowing."."Semi-natural grasslands belong to the most species rich ecosystems in the world."."Semi-natural grasslands are one of the world's most biodiverse habitats on a small spatial scales.".They can also be described as the following: Grassland existing as a result of human activity (mowing or livestock grazing), where environmental conditions and the species pool are maintained by natural processes.Semi-natural grasslands are a very common subcategory of the grasslands biome. "A region with sufficient average annual precipitation (25-75 cm) to support grass." (Stiling, 1999).".terrestrial ecosystems dominated by herbaceous and shrub vegetation, and maintained by fire, grazing, drought and/or freezing temperatures." (Pilot Assessment of Global Ecosystems, 2000). ![]()
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