9781422277522

and interwoven with grass roots. The total length of roots under a square metre of prairie is 24 miles (38 kilometers). Some prairie grasses have deep roots, which are useful in times of drought. These may reach down 10 to 15 feet (3 to 4.5 meters). Understanding the Ecosystem The activity in grasslands takes place at three levels—on a tiny scale below the surface, on a larger scale among the grass stems, and on an even larger scale above ground, where grazing ani- mals and their predators live. All three levels are rich and com- plex habitats. Underground, the dense mat of grass roots is home to vast numbers of burrowing creatures. These include many different A biome is a very large ecological area, with plants and animals that are adapted to the environmental conditions there. Biomes are usually defined by physical characteristics—such as climate, geology, or vegetation—rather than by the animals that live there. For example, deserts, rainforests, and grasslands are all examples of biomes. Plants and animals within the biome have all evolved special adaptations that make it possible for them to live in that area. A biome is not quite the same as an ecosystem, although they function in a similar way. An ecosystem is formed by the interaction of living organ- isms within their environment. Many different ecosystems can be found within a single biome. Components of most ecosystems include water, air, sunlight, soil, plants, microorganisms, insects, and animals. Ecosystems exist on land and in water, with sizes ranging from a small puddle to an enormous swath of desert. Biome versus Ecosystem

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Grasslands