Fragile Environments Flashcards
What is an ecological footprint?
A measure of the mark humans make on the world / the area needed to support a populations lifestyle.
Explain sustainability
If we continue to use natural resources we need to do so in moderation
Reduce ecological footprint
Sustainability = balance if the environment, society and the economy.
Be aware how balances can be upset.
What are the three types of soil erosion?
Sheet erosion - moderate rainfall, top soil is removed by rain down slope
Gully erosion - intense rainfall, the force cuts gullies in slopes
Wind erosion - dry parts, soil is blow off by wind
Name some causes of soil erosion.
Removing vegetation - soil is exposed
Overgrazing by animals
Over cultivating
Compacting soil - heavy machinery reduces the rate water can infiltrate the soil
Ploughing fields - encourages gullying
Climate change means unpredictable rainfall patterns - soil becomes too dry
Deforestation
Population growth - more pressure on land to make more crops
What are the natural causes of desertification?
Changing rainfall patterns (seasonal and unpredictable) - vegetation dies leaving bare soil / too much and dry land cannot hold water
All types of soil erosion
What are the main human causes of desertification?
Population growth- more trees felled
Overgrazing - destroy vegetation, none left just arid land
Over cultivation
Deforestation - no longer roots to bind the soil
Climate change
Less livestock in drier areas of desert
What are the consequences of soil erosion?
Malnutrition Famine and starvation Migration / refugees Food aid Reduced agricultural output
How can soil erosion be managed?
Use trees and hedges as wind breaks
Terracing protection for sheet and gully erosion
Contour plough slopes - ploughing along the line
Plant cover - reduces impacts of weathering
Maintaining water: - small dams
- earth walls along contours
- planting trees
Permaculture - organic farming, healthy, use of livestock and rotation
What is permaculture?
Type of organic farming
No chemicals from outside the area used
Grow mix of Food and tree crops
Use livestock, rotate them around to excrete and fertilise different areas, then move on to let areas regrow.
What are the causes of deforestation?
Commercial logging (cutting down trees to sell)
Road building
Population growth
Agricultural practices
Mining
Hydroelectric power (need space to build a dam)
General development
Why have governments encouraged the clearance of forests?
Revenue from timber helps pay off debt
More land is needed for houses
What are the layers of the rainforest?
Emergents Canopy Shorter younger trees Shut in layer Ground layer
What are the consequences of deforestation?
Contribution to global warming - more CO2
Flooding - because eroded soil deposited in river
Soil erosion
Native tribes forced into smaller areas
Loss of habitats
Leaching - rainfall easily washes away nutrients from bare soil
Sustainable management of any resource should ………….
Respect the environment Use traditional skills and knowledge Give people control over land and lives Use appropriate technology Generate income Protect biodiversity
How can sustainable management of a forest be achieved?
Protection of forests (none or very little development allowed)
Carefully planned + controlled logging
Selective logging of only valuable tress
Replanting felled forest areas
Restriction on number of logging licences
Helli-logging - helicopters remove logs as less damage
Developing alternative energy supplies (from renewable sources, to reduce amount of wood needed for fuel)