Deforestation — The Disappearing Rainforest
Rainforests are disappearing very quickly. You read about it in the paper, see it on television, and learn about it in school. You might wonder if it's so bad, why do people keep doing it? We have talked about how people cut rainforests for the valuable timber or clear rainforest for farming. But there are other reasons as well. You might not like to hear this, but we, here in the United States, might be part of the reason. Here's how.
In Brazil the rapid slashing and burning of the rainforest is mostly for commercial use of the land — for cattle ranching. Brazil is one of the world's leading exporters of beef. The cattle that are raised there must be moved often, because the thin soil doesn't support their grazing for very long.
When they need more grazing land, where do you think they get it? Yes, that's right, they cut and burn more rainforest. So how do we in the United States support the Amazon rainforest being cut down in Brazil? The answer is that the beef raised there is sold to fast food restaurants in the United States and Europe. One thing is for sure — Americans love fast food hamburgers!
Eat a Soy Burger!
Americans are big consumers of fast food, especially kids! But most fast foods are full of fat, excess calories, and cost a lot. The fast food industry also buys a lot of beef from Brazil where rainforests are being stripped to make room for more beef cattle. So next time you have a craving for fast food, have a soy burger instead. You never know, you might love them!
Deforestation Frustration — Erosion
When forests are completely cut down, it removes all the protection from the soil. Serious erosion can result. Try this experiment to see what happens to the soil that's left behind. You will need an open soil area outside — a garden spot before any seeds are planted is perfect, some grass clippings, some dead twigs, a hose with a spray nozzle, and a gardening trowel (little shovel).
Loosen the soil with the trowel, and make three mounds a few inches high.
Leave the first mound as it is. It is an area cleared of trees completely.
Cover the second mound with grass clippings and stick in a few (3–4) broken twigs. This is an area that has been cut for timber selectively.
The third pile should get twig trees stuck into it thickly like a forest, then top it with a blanket of lawn clippings in between. This is an uncut forest.
Using the hose on the widest spray pattern (with the least water pressure), spray the three mounds evenly. Spray them until tiny streams of water are running down the unprotected mound. Turn off the water.
Examine the three mounds. How did they each fare under the hose's spray? Did the unprotected mound wash away with no vegetation to protect it? Did the timbered mound have less erosion than the unprotected mound? How mound? How did the forested mound do? Can you guess how a clear-cut forest would do in a big rainstorm?
Desertification is usually caused by poor agricultural practices compounded by drought. You can test this theory with a simple experiment. You will need a potted plant, another pot of soil about the same size as the plant (it should never have had a plant in it, just soil), a fan, some old newspapers, and a sunny spot by a window.
Set the two pots side by side in the window. Water them both the same amount. Then let them sit for a week with no water.
After a week (depending upon how sunny it is) they both should be pretty dry. Now you can water the plant, but NOT the soil. The plant represents how areas with vegetation have more active water cycle activities going on, so the planted habitat will get some rain. The empty pot is overgrazed terrain that is getting no rain activity.
After about a month of watering the plant once a week (and not watering the drought-stricken overgrazed region) you are ready to demonstrate the consequences of desertification.
Lay both pots on newspaper next to a wall. Make sure the newspaper comes up the side of the wall a bit to protect it.
Now turn on the fan facing the plants against the wall. Let the air blow on both pots. It can be a light breeze or a strong gusty wind.
What effect did the wind have on the two pots? Did the plant and moist soil protect the potted plant from losing as much soil as the empty, dry pot? This is a simplified look at the extreme consequences of desertification.
The effects of deforestation are sometimes surprising. It's sad to see a beautiful rainforest cut down and know the animals have lost their habitat, but these are not the only reasons to worry about deforestation. Rainforests play a part in our global environment. They house many different kinds of animals and plants, helping to preserve biodiversity. They play a role in the oxygen cycle, supplying badly needed oxygen to our atmosphere, while taking in all the carbon dioxide we make. They hold moisture in the atmosphere, acting like giant, green sponges. When you cut down a rainforest, you lose the protective cover of the trees and the bare ground is pounded by rain, losing its topsoil to erosion. Once gone, new soil can take generations to develop. Plus, what happens to the soil that gets washed away? It can cause other environmental problems. It washes downhill into rivers and builds up. This is called sedimentation. The river fills in and gets shallower. Boats then can't travel in the shallow waterways. The river can become murky, making fishing a lot harder. All of these things affect the lives of the people and animals in and around the rainforest. These are just some of the dramatic side effects of deforestation.