The Amazon

In the blog post about rural changes I mentioned a lot about changes in LEDCs. One example used frequently in the books and websites is the Amazon Rainforest, so here I am going to explore a little more about the soil degradation and loss of ecosystems caused by these changes to the rural areas.

The Amazonian tropical rainforest is found between 10˚ North and 10˚ south of the equator. Due to the constant high temperatures, humidity and daily rainfalls, this is an optimum place for plant growth, rich plant diversity and lots of endemic, superbly adapted animal species. However, this is all under threat due to forest clearance - 100,000 kilometres of forest are being cut down each year.

Why?

Commercial clearances for timber harvesting have been going on in the Amazon for centuries. This is because there is high demand for the tropical mahogany and teak to make hard wood flooring and furniture. Despite the UK and many other countries restricting imports on these products, the trade still continues with disastrous consequences for the rural Amazon.

What else?

The building of hydroelectric dams; the Grande Carajas development programme; the building of new roads and forest clearance also have an impact on the soil degradation and loss of ecosystems. These are detailed below:

Hydroelectric dams

80% of Brazil’s power comes from hydroelectric dams, but two thirds of the potential is untapped. There are 48 planned dams, 30 of which are in the Amazon basin. The building of hydroelectric dams along the Amazon’s tributaries has been known to flood the Amazon basin resulting in ecosystem damage. For example; Brazil’s Balbina dam near Manaus, flooded 2,400 square km of rainforest.

The Grand Carajas development programme

The Grand Carajas is the largest iron ore mine and aluminium plant in the world. It is right in the heart of where untouched forest once stood and is thought to continue being economically worth-while for 400 years. Not only is the mining bad for the environment, there would have been many ecosystems ruined in the clearing of the land and there was wood used as fuel, which led to further clearances.

The building of new roads

Over the last few decades the number of roads and highways being built through the Amazon has increased. As mentioned above, tropical forests, such as the Amazon, have a complex structure and humid microclimate that sustain a large number of endemic species. Many of these species avoid altered habitats near roads and cannot cross any sort of clearing. Any that do risk crossing the road are at danger of being hit by vehicles or killed by people hunting near roads. These new roads therefore, aid in diminishing or fragmented wildlife populations and can lead to local extinctions. New roads also promote other deforestation.

Forest clearance

95% of forest clearance and fires occur within 50km of roads. Huge areas are cleared for commercial agriculture, for crops such as soya beans. Landless farmers also move to Amazonia along new roads and cut down the forest for firewood, or to grow crops. This issue with this is that the more of the Amazon is cleared forests for farming, the less productive the farming will be due to reduced rainfall and rising temperatures caused by feedbacks on the regional climate.

The topic in teaching…

I have seen lesson plans on the internet for whole lessons on the Grand Carajas development programme alone, so depending on timescales and age range there are a variety of opportunities. A lot of information is covered on the Amazon in the ecosystems topic, so one would need to be careful to not cross over. The topic is really interesting nonetheless and worthy of at least a fact file, hence the blog post.

  

References

Yates et al., 2009. Edexcel GCSE Geography B Evolving Planet text book.

http://www.economist.com/news/americas/21577073-having-spent-heavily-make-worlds-third-biggest-hydroelectric-project-greener-brazil

http://www.goodplanet.info/eng/Contenu/Points-de-vues/Roads-are-ruining-the-rainforests/(theme)/267

http://www.google.co.uk/url?sa=t&rct=j&q=the%20grand%20carajas%20development%20programme&source=web&cd=1&ved=0CC0QFjAA&url=http%3A%2F%2Fintranet.horbury.wakefield.sch.uk%2Fmedia%2FDepartments%2Fgeography%2FBrazil%2FThe%2520Grand%2520Carajas%2520Scheme.ppt&ei=r84DUtLADuqG0AX_m4CoDA&usg=AFQjCNGU40KrB_BplKFYkhvfFhQBqc_3mg&bvm=bv.50500085,d.d2k

http://www.theguardian.com/environment/2013/may/10/amazon-clearance-agriculture-economic-own-goal