Prairies- Then…and Now
Prairies: Then
"I ascended to the top of the cutt bluff this morning, for whence I had the
most delighfull view of the country, the whole of which except the valley
formed by the Missouri is void of timber or underbrush, exposing to the first
glance of the spectator immense herds of Buffaloe, Elk, deer, & Antelopes
feeding in one common and boundless pasture."
– Meriwether Lewis, April 22, 1805
When Lewis and Clark crossed the Great Plains, it was one of the world’s largest grasslands,
rivaling the plains of South Africa and Africa’s Serengeti. The prairies once spread from
Indiana to the Rocky Mountains, from southern Canada to northern Mexico, and occupied
more land than any other ecosystem in North America. Outbound, it took Lewis and Clark
more than a year to cross the prairie, what Wallace Stegner called our "grand ocean of
wind-troubled grass and grain."
Today, that ocean is gone. More than 90 percent of our
native prairies have been lost, most to cultivation.
Scattered over 12 states are just 20 patches of federally
owned prairie. Even within the National Grasslands, our
prairies have been breached by mining, roadbuilding,
and oil and gas drilling.
Only 550,000 undeveloped acres remain, yet none of the
National Grasslands is protected as wilderness. As many as
70 million bison (more commonly known as buffalo), 40
million pronghorn antelope and 5 billion prairie dogs lived on the Great Plains at the time of
Lewis and Clark. Historian Paul Russell Cutright believes it is "impossible for anyone alive today
to comprehend the abundance of game that once populated the plains of the West."
Lewis and Clark recorded hundreds of grassland animals previously unknown to science,
including the grizzly bear, black-footed ferret, bighorn sheep, coyote, prairie chicken and
black-billed magpie. Settlers who followed the explorers, exterminated grizzlies and bighorn
sheep from the plains, leaving only isolated populations in the mountains. Wholesale
slaughter almost eliminated the pronghorn and the buffalo.
By 1883, just 15 years after an immense herd of buffalo held up a westbound train for eight
hours, there were only 350 wild buffalo left. The creation of Yellowstone National Park saved
the buffalo. It’s where the remaining animals took refuge and made a comeback. Today,
there are an estimated 200,000 buffalo, about 20,000 of them still wild. Prairie-dog towns
covered as much as 20 percent of the prairie when Lewis and Clark crossed it.
Today, 98 percent of the prairie-dog towns have been eliminated and the prairie dog —
which acts as a living plow, churning up the loam, keeping the soil loose and arable—is still
being poisoned and shot, dismissed as a "varmint" as it has been for decades. Prairie dogs
are the key to survival for species such as raptors, badgers, swift fox and black-footed ferrets.
Prairies… Now
What Are the Impacts of Humans on Grassland Biomes?
by Kevin Carr, Demand Media
Human population growth has a major impact on the different biomes of the Earth. Grassland biomes,
characterized by large areas of land where grasses are the primary form of plant life, are affected by
expanding human civilization in particular ways. The grazing land for many species of animals, which in turn
provide a food source for larger predators, is often at risk.
Urban Development
The biggest impact that humans have on grasslands is by developing open areas for farming or urban
development. Such development is prevalent because grasslands are generally level areas with little need for
major work to develop the land. The development of land drives animals away from populated areas and
changes the conditions of the environment.
Farming
When grasslands are converted into cropland, it reduces the food source for many wild animals. In this case,
the animals are considered pests by the farmers when they feed on the crops. This can lead to migration or
possibly the starvation of the animals. Not only does the conversion of land into crops change the ecosystem,
but so does the farming of livestock. If livestock are allowed to graze in areas where wild animals live, they
compete over the food source and can deplete it. This overgrazing is a problem especially in the drier
grassland regions, where the grasses resources can be depleted. The land can also be plowed too much,
stripping the nutrients from the soil. Salts from irrigation waters can also damage the ground, resulting in the
blowing away of the dry soil. This is the process that created the Dust Bowl in the American west in the 1930s
and continues to cause major dust storms.
Hunting
Hunting has had and continues to have a serious impact on the biome. The American bison population was
devastated by the European settlers and almost became extinct due to overhunting for the fur and meat.
Poachers are likewise killing rhinoceroses for their tusks and elephants for their ivory in Africa.
Global Warming
As the Earth's climate changes in response to human involvement, the grasslands become vulnerable. Climate
change can cause ecological succession, in which the ecosystem of an area develops into another. Changing
temperatures, weather patterns and water availability can throw an area of grassland out of balance and
change it forever.
Fires
Because grasslands can be found in drier climates, the plant life is susceptible to fires. Wildfires occur as a
natural process within an ecosystem and play a critical role in replenishing the land. However, fires tend to
originate more frequently near human populations, particularly in drier months.
Positive Impacts
Humans do not have only a negative impact on grasslands. There are some that do their part to preserve the
land and restore it. National parks have been developed around grasslands and some organizations replant
areas of depleted grassland. Governments have enacted laws against the hunting of endangered animals. In
particular, the U.S. National Parks Service has preserved land to foster the American bison population. While
poaching still exists in many areas, there are efforts to stop it.
Name: _____________________________________________ Period: ________
Prairies – Then and Now
1. Describe what American explorers, Lewis and Clark, observed when
they first viewed the American Prairie in 1805. ________________________
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2. What was the dominant type of plant growing in the prairies? ___________________________
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3. Why is there no mention of trees growing? Can you think of a reason why they would not
be able to grow? ________________________________________________________________________
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4. What were some animals that roamed the prairies in great numbers? ____________________
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5. Explain the changes that have affected the bison population over the last 200 years.
What caused the population decrease? What role has the government had in restoring the
population? _____________________________________________________________________________
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6. More than 90% of our native prairies have been converted into farmland. Describe an
example (in detail) of how this change has greatly impacted the prairie region.
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7. What do you think historian Paul Russell Cutright meant by “it is impossible for anyone alive
today to comprehend the abundance of game that once populated the plains of the
West?”___________________________________________________________________________________
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8. REFLECTION:
If Lewis and Clark were to revisit the prairies today, what would be the most significant
(important) change they would observe? How do you think they would feel about this
change? Explain in detail. _______________________________________________________________
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What Are the Impacts of Humans on Grassland