Grassland

A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area. Included among the variety of definitions for grasslands are: "...any plant community, including harvested forages, in which grasses and/or legumes make up the dominant vegetation." "...terrestrial ecosystems dominated by herbaceous and shrub vegetation, and maintained by fire, grazing, drought and/or freezing temperatures." (Pilot Assessment of Global Ecosystems, 2000) "A region with sufficient average annual precipitation (25-75 cm) to support grass..." (Stiling, 1999) Semi-natural grasslands are a very common subcategory of the grasslands biome. These can be defined as: Grassland existing as a result of human activity (mowing or livestock grazing), where environmental conditions and the species pool are maintained by natural processes. They can also be described as the following: "Semi-natural grasslands are one of the world's most biodiverse habitats on a small spatial scales." "Semi-natural grasslands belong to the most species rich ecosystems in the world." "...have been formed over the course of centuries through extensive grazing and mowing." "...without the use of pesticides or fertilisers in modern times." There are many different types of semi-natural grasslands, e.g. hay meadows. The graminoids are among the most versatile life forms. 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.

Responses of permanent grasslands to drought during the plant growing season: combining agronomic, functional and ecophysiological approaches

Responses of permanent grasslands to drought during the plant growing season: combining agronomic, functional and ecophysiological approaches