HUMAN IMPACT ON THE RAINFOREST

Hundreds of years ago rainforests were not under threat human activities. Despite rainforests catering for small tribes of people, these tribes had very little effects on the ecosystem. However, today rainforests are under great threats as ‘our’ actions are destroying them – rapidly! The main problem is deforestation!

Deforestation is happening quickly! Too quickly! Trees are being felled at a much quicker rate than what they are growing at. It is feared that by 2030 the world’s rainforests may be gone. To put this into perspective, in the Amazon it is thought that 2.5 hectares of forest are cleared each minute! This is the equivalent of 5 football pitches! (I will make reference to the Amazon throughout this post to give an outline of the scale of the human activities listed below).



Logging



Economic exploitation

Logging – there is a high demand for hardwoods such as mahogany and rosewood from the rainforests. Consumers in MEDCs will pay a lot of money for furniture made by these woods. However for every tree cut down it is believed that 30 others may be damaged or destroyed in the process. Five million hectares of forest are lost in the Amazon as a result.  

Mining



Mining – Some rainforests have developed above mineral rich resources. One of the main minerals found in Amazon rainforest is iron ore, also known as haematite. This is mined and exported to steel making countries. However this mining process is destroying huge areas of forest in the process. Iron ore is not the only mineral found in the rainforest, other metal ores such as gold, platinum, copper, lead, and bauxite can be found.



Cattle ranching



Cattle ranching – Another reason for the clearing of land is so farmers can rear their cattle. Since 1950, it is estimated that two-thirds of the Amazon’s lowland forest has been turned into pasture for grazing. Due to overgrazing, the nutrients in the soil decline making the quality of the grass poorer. This has resulted in ranches expanding their land for better quality soil and grasses.



Peasant farming – This is at a much smaller scale, but due to over-crowding in cities (particularly in Brazil) citizens have been pushed into the rainforest with permission to clear land for farming, however due to infertile soils, this has not been entirely successful.

 

I have found a useful link that provides a work sheet used in a school for Year 10. I think it would be effective for students working at GCSE level to take a look at it. It can be found on: http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=10&sqi=2&ved=0CHIQFjAJ&url=http%3A%2F%2Fwww.geography.learnontheinternet.co.uk%2Fvgd%2Fresources%2Fyear10%2Fecosystems%2Fwhatistheimpactofhumansinthetropicalrainforest.doc&ei=b7I3ULWJEuLS0QWZyYGQDg&usg=AFQjCNGrViY4d25e6KOBISE41rFxgNqoXA&sig2=IKoRFTq7ku4yfic84BEM7Q

 The National Geographic has provided lesson ideas and activities that can be used within the classroom with high school students. Some of the activities are very time consuming however may provide inspiration when developing personal lesson activities. See: http://www.nationalgeographic.com/xpeditions/lessons/14/g912/fayhuman.html

 

Links:

http://www.rain-tree.com/facts.htm

http://biology.clc.uc.edu/courses/bio303/human%20interactions.htm