Remember, they're TOPICAL forests too....
As one of the final parts of the A2 course, you will be researching the biome above. This will then act as a case study for both the Ecosystems topic and the Synoptic paper. Remember that you already have TEMPERATE GRASSLANDS as a case study, and information on several other biomes as well.
You will spend 1 or 2 lessons in classroom and up to 4 lessons in the ICT rooms - the aim being to gather information and present it in an easily digestible format for YOUR OWN REVISION, and SUITABLE FOR ESSAYS...
The best information will be transformed into web pages and form part of the popular website: http://www.geographypages.co.uk - a form of immortality! (as long as you want them to be....)
If you find any additional websites let me know them and I'll add them to the site.
The secondary target is to produce a POWERPOINT presentation made up of no more than 8 slides which summarises the issues surrounding the management of tropical forests.
Remember what MANAGEMENT actually involves.
The following sections are taken from the syllabus:
For examples of main global biome types, need to know: human and physical factors affecting spatial and temporal variations in productivity
Influence of terrestrial, atmospheric and human factors on the distribution, structure and functioning of ONE forest biome.
The role of human activity in producing plagio-climax communities.
Synoptic: The management opportunities and challenges associated with forest ecosystems.
You will need to use the sites HERE, and your own searches (not that you need to bother really - I've done them for you..)
to provide the following, in relation to the AMAZON RAINFOREST (named location)
The motivation is that you will need these for your revision, and need to prepare materials that could be inserted into an ESSAY.
1. Locate a map of the Amazon rainforest. You will need to name different regions of the forest.
2. Why are forest ecosystems described as 'fragile' ? Locate a diagram which illustrates the forest ecosystem
3. Give some examples of sustainable use of the forests.
4. What is meant by secondary forest ?
5. What effect does forest clearance have on soils ?
6. What are the predicted effects of large scale clearance on global climate ?
Aim at producing 1 illustrated A4 side, or a couple of Powerpoint slides on each of these areas.
Enjoy....
Rainforest Fact-File:
3 major forest zones: Amazon basin, Zaire basin in W. Africa & fragmented areas of Indo-Malaysia stretching to N. coast of Australia
Tropical rainforests are a good example of a crowded, productive ecosystem.
Centred on equator. Rainfall between 2-3000mm per annum. Mean annual temperature 27°C, with a small temperature range.
Rainforest is confined to equatorial regions of the world, occupying hot, humid low-lying river basins such as the Congo, Niger, Amazon and Essequibo.
Biodiversity is famously high compared with other rainforests. Hot, wet, plenty of light but with poor-nutrient soils. Rainforest species tend to be very tall, with a canopy which captures the insolation.
Rainfall most afternoons: intense and convectional in nature. Much of rain is recycled.
High NPP: high organic content: 23 tonnes per hectare per year
Dense vegetation: stratified structure. Most plants are deciduous, but the forest appears evergreen as different plants have different flowering cycles.
Emergent zone: tallest trees e.g kapok, up to 50m tall.
Canopy at around 30-40m: absorbs 80% of insolation. Below this is the undercanopy, and then the shrub layer on the forest floor. Forest floor only receives 1% of light incident on canopy.
Trees have leaves which swivel to face the sun. Drip tips to shed surface water. Waxy coating to reduce evapotranspiration loss. Emergent trees will have smaller leaves.
Epiphytes and lianas and other parasitic plants, bromeliads covering the trees.
Trees grow straight and tall - few side branches - buttress roots as support.
Few plants are wind pollinated, so rely on animals to spread seed: tend to be relationship between certain plants and animals (symbiotic)
Very swift decomposition means that nutrients are rapidly cycled back to the plants, so majority of biomass is in the trees rather than in the soil. Soils are quite poor, and have acidic pH. Soils are highly weathered, and have only a thin organic layer. If forest is cleared, the soils won't provide sufficient nutrients to allow regeneration. Form a surface layer called a duricrust. Soil erosion is rapid, and fertility also declines rapidly.
Secondary forest begins to fill in any gaps and attempt to re-colonise cleared areas but it is never the same as the primary or virgin forest.
Dangers of clearing the rainforest:
Nutrient cycle interrupted
Upper soil-humus layer is destroyed
Trees no longer protect soil from rain-splash erosion
Soils can't retain nutrients.
Loss of species diversity.
DEFORESTATION WEB
Start with the word DEFORESTATION in the middle of the page, and start to develop ideas as to the effects of this on various aspects of the forest.
You could perhaps provide the next level of the web, which would include statements such as:
RAINFOREST SITES
Some useful extra details:
An article on the link between TOBACCO and deforestation. Another way in which people are linked to distant events. Brazil is the world's largest exporter of tobacco. Trees have to be felled to plant tobacco, and then fuel-wood is needed to dry out (cure) the tobacco from green to brown.
A superb FRENCH ONE here, which summarises the main issues. There are others from this site too.
RAINFOREST ACTION NETWORK and RAINFORESTWEB are 2 particularly sound ones.
PRINT RESOURCES
We also use the following print based resources:
Geo Factsheet Number 25 (September 1997) - "Energy Flow and Nutrient Cycling in Tropical Rainforests"
Article from 'The Guardian' - 12/01/06 - which makes them 'topical' rainforests...
Understanding Global Issues 2/92: Amazonia: an ecological crisis
