Grasslands are as the name suggests dominated by grasses, but usually there are low shrubs and broad-leaved flowers mixed in amongst them too. Grasslands are called "steppe" in temperate latitudes (from a Russian word), while in the tropics they are called "tropical grassland". The term "savanna" tends to be applied to warm climate grasslands that have an open scattering of trees or shrubs. The steppe grasslands fade in to "tundra" in high latitudes and at high altitudes on mountains. Tundra can have a lot of grasses, and mosses, but is often dominated by a rather prickly mass of low shrubs: dwarf willows, dwarf alders and dwarf birches, mixed with lichens. Thus, sometimes tundra can be a grassland, sometimes it is essentially a low scrubland.
Grasses grow from buds right down next to or underneath the ground, and can recover from fire or grazing very easily. They also have long leaves that grow by pushing out from their base, like toothpaste out of tube. This also means that they can regrow very easily if the tops of the leaves are burnt or eaten. In fact, most grasses seem to "need" frequent fires or grazing to keep other plants out. In the absence of either type of disturbance, the grasses are usually out-competed by other plants such as trees or shrubs. Thus, grasses can have a strange indirect arrangement with grazing animals; the grazers kill parts of the grass, but the grass needs the help of the grazers in seeing off the competition.
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