World Biomes Temperate Grasslands. Climate Semiarid, continental climates of the middle latitudes...

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Transcript of World Biomes Temperate Grasslands. Climate Semiarid, continental climates of the middle latitudes...

World Biomes

Temperate Grasslands

Climate

• Semiarid, continental climates of the middle latitudes typically have between 25 cm and 50 cm of precipitation a year. Much of this falls as snow, serving as reservoir of moisture for the beginning of the growing season. Warm to hot summers are experienced, depending on latitude.

• In the winter, grassland temperatures can be as low as -40° C, and in the summer it can be as high 20° C. There are two real seasons: a growing season and a dormant season. The growing season is when there is no frost and plants can grow (which lasts from 100 to 175 days). During the dormant (not growing) season nothing can grow because its too cold.

Distribution of biome

• Grassland biomes can be found in the middle latitudes, in the interiors of continents. They can have either moist continental climates or dry subtropical climates. In Argentina, South America, the grasslands are known as pampas. The climate there is humid and moist. Grasslands in the southern hemisphere tend to get more precipitation than those in the northern hemisphere, and the grass tends to be the tall-grass variety.

Distribution

Soil

• Calcification is the dominant soil-forming process in semiarid regions. When this process works on a loess that itself is rich in calcium, the world's most fertile soils are created, the chernozems (A Russian term meaning black soil).

Plants

• Perennial grasses and perennial forbs are dominant growthforms. Two or more strata of grasses are recognized in the more humid expressions of the biome.

• Perennial grasses, with their growth buds at or just below the surface, are well-adapted to drought, fire, and cold. The narrow, upright stem reduces heat-gain in the hot summers; the intricate root systems trap moisture and nutrients. Two basic types are: – The first type is with rhizomes or underground stems from

which new plants spring forth; associated with the more humid grasslands

– The second type is without rhizomes, that reproduce by seed; associated with the drier parts of the biome.

Rhubarb Sweet vernal

Indian Grass

Purple Coneflower

Pampas Grass

Animals

• The temperate grassland fauna is very low in diversity, especially in comparison with the tropical grasslands or savannas of Africa. A lot of the animals that live in Steppe are grazing animals, such as rabbits, mice, antelopes, horses, etc. Smaller animals have little defence from predators. Since it is such an open environment and predators can find animals fast, they either form herds or make burrows. There are many endangered animals on the Steppe.

Rhea

Mongolian Gerbil

Saiga

Prairie dog

Bison

Coyote

People

• Few natural temperate grassland regions remain because most have been turned into farms or grazing land. This is because they are flat, treeless, covered with grass, and have rich soil.

• Overgrazing, ploughing, and excess salts left behind by irrigation waters harm temperate grasslands.

• Strong winds blow loose soil from the ground after ploughing, especially during droughts.