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Environment

Information about the environment. Although very lush, and once considered to be foodbasket for the world - but in reality, if deforestation continues to occur at the current rate, Amaz⌠nia could become world's biggest desert.

Farms that are settled on land cleared from the rain forest do not produce very much food. The plants don't grow very well, and eventually nothing will grow at all. After a few years most farms fail entirely and the farmers have to clear new land. The reason for this is the the Amazon soil is very bad – there are very few of the nutrients in it that plants need to grow and survive. This is very strange for a place that have some of the most lush rain forests in the world!

The poor quality of the Amazon soil is compensated for by a highly-refined ecology where plants grow and die very quickly (new plants receive nutrients for old plants decaying on the forest floor) – simply recycling very quickly the few nutrients that are around.

Once deforested, the nutrients are washed away by the rains. Very little grows, and the soil just cakes in the hot sun – turning to mud in the rain.

The Indians in the forest have always used a slash-and-burn approach. They farm a small clearing in the forest for a few years, then once the soil has run out of nutrients they will leave the village and move to a new site (leaving the old site to fallow and regenerate - taking many years). This works on the small scale used by the Indians, but does not work with the huge areas being cleared for farms for the new settlers from other parts of Brazil.

Link to Rainforest chapter (environment) – explain how the rainforest works, the oxygen cycle, and the rain forest's environmental importance (oxygen and weather patterns). Try to explain the subject in English, with diagrams - and verify how it fits in with the Science curriculum. Need to find uptodate information and theories

(text from "The Rivers Amazon", pp30-31)

". . . estimated that .5 to 1.5 percent of the world's rain forests is being cut annually, about two-thirds of which grows in the Amazon valley. If the rate is taken to be 1 percent, then half of the estimated .. carbon that are being released into the atmosphere annually comes from burning rain forest (the other half comes from burning fossil fuel). If this trend continues, by the year 2020 the atmospheric carbon levels will double. Carbon dioxide is a critical determinant of climate because it absorbs radiant energy at infrared wavelengths and contributes to the so-called "greenhouse" effect. Woodwell predicts a warming of the world's climate over the next few decades that will severely disrupt agriculture and fisheries, and almost every other biological activity of man.

The concern voiced widely a few years ago, that cutting the Amazon rain forest would deprive the world of its major producer of oxygen (the most commonly heard claim is that two thirds of our oxygen is produced in the Amazon valley) is no longer taken seriously by most scientists. Most of our oxygen, they have found, is produced by algae floating in the oceans. The Amazon is a mature forest ... it requires as much oxygen as it releases.

But another concern that IS being taken seriously: when an area is stripped of forest, it is stripped, by ecological feedback, of its rainfall. There is no information on what would happen to the world's weather patterns if the Amazon valley became a desert, but the consequences would undoubtedly be grave."

Link to Rainforest Action Network (RAN) site. They have a very well set out Internet site, easy-to-use, colourful, and with very good information about this subject.

Link to River chapter (environment) The waters of the Amazon river are either too acidic (because of decaying plant material) or too alkali (because of all the sediment from the Andes) to support much life. Life in the river occurs primarily where the flows of two rivers (dark and white) merge and neutralise one another. Development is causing other problems. For example, the most common way of extracting gold is by using mercury. However, the run-off goes into rivers, poisoning plants, fish, and people (particularly in the traditional Indian hunting grounds). There are also problems with overfishing and poaching (eg. of turtles for export, and of turtle eggs). Alex Shoumatoff wrote a very interesting article about several days spent with the Brazilian conservation enforcement people, travelling upriver, and checking passing boats for poached turtles and turtle eggs.

Related Activities

Students may wish to look at comparisons in NZ with overfishing (whitebait and oysters) and find out about what DOC and MAF do. What are some NZ projects that might be of interest. Local projects?

Are there things about the New Zealand environment that might worry us? What is pollution? Are there things that we do in our everyday lives that affect our environment? The class may wish to do some sort of study or fieldwork.