Global Environment

Global Environment.com

Biodiversity    

Grasslands

Grassland biomes are large, rolling terrains of grasses, flowers and herbs. Latitude, soil and local climates for the most part determine what kinds of plants grow in a particular grassland. The soil of most grasslands is too thin and dry for trees to survive.

 
Grassland Location Map
   
 
   
 

When the settlers of the United States moved westward, they found that the grasslands, or prairies as they called them, were more than just dry, flat areas. The prairies contained more than 80 species of animals and 300 species of birds, and hundreds of species of plants.

Grassland*Steppes of Eurasia

*North American Prairie

*The Pampas

 

 



When the settlers of the United States moved westward, they found that the grasslands, or prairies as they called them, were more than just dry, flat areas. The prairies contained more than 80 species of animals and 300 species of birds, and hundreds of species of plants.

There are two different types of grasslands; tall-grass, which are humid and very wet, and short-grass, which are dry, with hotter summers and colder winters than the tall-grass prairie. The settlers found both on their journey west. When they crossed the Mississippi River they came into some very tall grass, some as high as 11 feet. Here it rained quite often and it was very humid. As they traveled further west and approached the Rocky Mountains, the grass became shorter. There was less rain in the summer and the winters got colder. These were the short-grass prairies.

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.

There is a large area of grassland that stretch from the Ukraine of Russia all the way to Siberia. This is a very cold and dry climate because there is no nearby ocean to get moisture from. Winds from the arctic aren't blocked by any mountains either. These are known as the Russian and Asian steppes.

In the winter, grassland temperatures can be as low as -40° F, and in the summer it can be as high 70° F. 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.

In tropical and subtropical grasslands the length of the growing season is determined by how long the rainy season lasts. But in the temperate grasslands the length of the growing season is determined by temperature. Plants usually start growing when the daily temperature reached about 50° F.

In temperate grasslands the average rainfall per year ranges from 10-30 inches. In tropical and sub-tropical grasslands the average rainfall per year ranges from 25-60 inches per year The amount of rainfall is very important in determining which areas are grasslands because it's hard for trees to compete with grasses in places where the uppers layers of soil are moist during part of the year but where deeper layer of soil are always dry.

The most common types of plant life on the North American prairie are Buffalo Grass, Sunflower, Crazy Weed, Asters, Blazing Stars, Coneflowers, Goldenrods, Clover, and Wild Indigos.

Some common animals in the grasslands are Coyotes, Eagles, Bobcats, the Gray Wolf, Wild Turkey, Fly Catcher, Canadian Geese, Crickets, Dung Beetle, Bison, and Prairie Chicken.


Steppes of Eurasia

The Steppe biome is a dry, cold, grassland that is found in all of the continents Steppes of Eurasia Location Mapexcept Australia and Antarctica. It is mostly found in the USA, Mongolia, Siberia, Tibet and China. There isn't much humidity in the air because Steppe is located away from the ocean and close to mountain barriers.

The Steppe biome is usually found between the desert and the forest. If it got more rain, it would become a forest. If it got less rain, it would become a desert. The average rainfall is 10-30 inches per year. But in May, June, and August, the Steppe can get up to 4-5 inches a month.

There are many plants in Steppe. The main ones are different grasses. The grasses are separated into 3 different groups, depending on how much rain they get. The tall grasses grow up to 4 1/2 feet because they live closer to the forest. The short grasses can be less than 1 1/2 feet. They are closer to the dessert. 1 1/2 feet is a small amount, considering that people don't cut the grasses. The last group is the mixed grasses. They grow 2-3 feet high and get 15-20 inches of rain per year.

Very few people live in the Steppe climate because it's only grass and it has very few other traits. Farmers would have a hard time growing crops because the soil is so poor and its so cold. There is also a lot of wind in the Steppe because there are few trees.

Steppe has warm summers and really cold winters. There is often a lot of snow in the northern Steppes. All the Steppes experience long droughts and violent winds. Sometimes the summers are so hot that the grasses catch on fire. That is more dangerous then usual because the grass is so dry that it spreads quickly.

A lot of the animals that live in Steppe are grazing animals, such as rabbits, mice, antelopes, horses, etc. Smaller animals have little defense 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. More and more people are trying to protect them.

A true natural grassland is becoming harder and harder to find because people are taking them over. They are plowing the grass for farming and digging holes in search of oil. The Steppe biome is becoming endangered, just like the animals.


North American Prairie

In the middle of North America is a huge area of land which was once covered North American Praire Location Mapwith grasses and colorful wild flowers. The French called the rolling plains of grass "prairie", from the word for a meadow grazed by cattle. The prairies are a type of grassland dominated by herbaceous plants and grasses. Very few trees grow on the prairies and are usually widely scattered.

The prairies form a triangular area from Alberta, Saskatchewan, and Manitoba down through the Great Plains to southern Texas and Mexico, and approximately 1,000 miles from western Indiana westward to the Rocky Mountains. They cover about 1.4 million square miles.

As you move from east to west, the rainfall in the prairies decreases. Climates are more moist close to the mountains and to the east and north; they are driest in the central portions. This creates different types of prairies, with the tallgrass prairie, known as the true prairie, in the wetter parts. Grasses such as big bluestem, and Indian grass, and many species of flowers grow here. The plants can sometimes grow to be 10 feet tall. Mixed-grass prairies are found in the central Great Plains, and shortgrass prairie towards the rain shadow of the Rocky Mountains. The rain shadow causes Pacific ocean moisture to rise and cool, dropping as rain or snow on the western side of the mountains instead of on the prairies.

Precipitation in the prairies can reach from about 12.6 inches in the shortgrass prairie to 21.7 inches in the tallgrass prairies.

The prairies were maintained in their natural state by climate, grazing and fire. Rainfall varies from year to year in the prairies. There is usually a long dry period during the summer months. Every 30 years or so there is a long drought period which lasts for several years. The most famous drought was in the 1930s, when the prairies were called the "Dust Bowl".

The climate of the prairies is influenced by its mid-continental location, and the sheltering effect of the Rocky Mountains. Being located far from the moderating effects of oceans causes a wide range of temperatures, with hot summers and cold winters. Strong winds blow across the endless plains during both summer and winter.

Every one to five years fire would spread across any given area of land. These fires moved rapidly across the land and did not penetrate into the soil very far. They killed most saplings, and removed the thatch of dead grasses, allowing early flowering spring species to grow.

Prairie plants have adapted to fires by growing underground storage structures, and having their growth points slightly below ground surface. The soil under a prairie is a dense mat of tangled roots, rhizomes, bulbs, and rootstock. The plants die back every winter, but are kept alive from year to year by the underground root system. Roots of prairie plants can by longer than the plant is tall. The roots of big bluestem may be 7 feet long, and switchgrass roots can be 11 feet long. Two-thirds of most prairie plant are below the ground. Some roots die each year and decompose, adding lots of organic matter to the soil. That's why the soil of prairies is so fertile.

Before settlers moved west, the prairies were covered with herds of grazing animals, such as buffalo, elk, deer, and rabbits. These animals increased the growth in prairies by adding nitrogen to the soil through urine and feces, and creating open areas for plants that like to have the soil dug up. Prairie dogs dug huge underground tunnel systems which aerated the soil and allowed water to reach several feet below the surface.

Today very little of the original prairies survive, only one to two percent. Much of the land has been turned into agricultural uses, urban areas are moving in, and fires are being suppressed. The genetic and biological diversity of the plants are disappearing. The herds of thousands of buffalo were all but wiped out. There is a strong movement to educate people about prairies. Many states are rehabilitating what is left of their prairies and reintroducing the native wildlife and plants.


The Pampas

The Pampas of South America are a grassland biome. They are flat, fertile plains The Pampas location mapthat covers an area of 300,000 sq. miles or 777,000 square kilometers, from the Atlantic Ocean to the Andes Mountains. It is found primarily in Argentina and extends into Uruguay. The word Pampas comes from the Guarani Indian word for level plain. The Argentinean Pampas are the home of the 'Gaucho', the original South American cowboy. The pampas is located just below Buenos Aires, between 34° and 30° south latitude, and 57° and 63° west latitude.

The average temperature in the Pampas is 18° C. The pampas has a 'high sun' or dry season in the summer, which in the Southern Hemisphere is in December. The wind blows most of the time. The climate in the pampas is humid and warm.

There are many kinds of animal and plant life in the Pampas. Native plants and animals on the Pampas have made adaptations to living in a windy grassland. Many animals browse on grass or burrow in the ground. There is even an owl that builds its nest in underground burrows. A few of the plants in the pampas include cattails, water lillies, reeds. These plants usually prefer wetlands but they have adapted to the dryer Pampas grasslands. There are not very many trees because fires frequently occur in the pampas. The fires do not kill the grasses, which regenerate from their root crowns, but destroy the trees, which have shallow root systems. The exception is the Ombu which has made adaptations to protect itself from fires.

Some animals include seed eating birds such as the Double Collard Seedeater, the great Pampas Finch, the grassland Yellow Finch, and the Long Tailed Reed Finch. It is also home to the Greater Rhea, a relative of the African Ostrich and the Australian Emu. In addition to birds, several interesting mammals can be found in the pampas. The Geoffroy's Cat, for example, with its gray coat and black stripped legs, is almost invisible in the mesquite and bunchgrass. The Maned Wolf has very long legs so it can see over the tall grasses. Also, one can find a llama-like Guanaco that lingers among the ponds. It is important to know that at least fifteen mammal species, twenty bird species, and fifteen plant species are at serious risk of extinction in the Pampas.

The humid Pampas ecosystem is one of the richest grazing areas in the world. Because of its temperate climate and rich, deep soil, most of the Pampas has been cultivated and turned into croplands. Unfortunately, domestic livestock and farming have severely affected the pampas. Fertilizers and overgrazing are a serious threat to the pampas. There are only a very few pristine remnants of the legendary "ocean of grass" that was the Pampas. It is considered to be one of the most endangered habitats on earth.

 
 

Top up arrow

 
 

Top up arrow

e-mail me Site Map