Unit 3- Deforestation Flashcards
Why are forests important?
- Forests cover 30% of land surface
- 350 million Ppl live within or close to forests
- One-third of humanity depends on forests for income and subsistence
- Water regulation
- 50% of biodiversity exists in tropical forests
- Create oxygen, absorb CO2
Forest def.
Biomes dominated by trees, where the foliage of trees forms a canopy. Land spanning more than 0.5 ha with trees higher than 5 meters, and a canopy cover of more than 10%, or trees able to reach this threshold in situ
Biome def.
A type of natural environment encompassing its biotic components of plants and animals, as well as the physical landscape they inhabit, especially covering large areas
3 levels/ types of forests
Primary
Secondary
Plantations
Primary forest
Intact, old-growth forests have remained relatively undisturbed for centuries and are still dominated by natural processes (34% of forests)
Secondary forests
Regrowth or regenerated forests, recently disturbed by human activities, regenerated by replanting or seeding (59% of forests)
Plantations
Monoculture of native or non-native trees for the commercial production of a particular species or for environmental services such as erosion control (7% of forests)
Deforestation def.
The long-term reduction of tree canopy cover to below 10-30% of its original cover (depending on forest type)
Forest degradation def.
Forests modified by human activities (selective logging, replanting, shifting cultivation and wood fuel collection). More than 10-30% of forest remaining
Forest fragmentation
Protracted deforestation- clearing of pockets of land mostly for roads, leaving pockets of forests. Over time, edges of forest pockets become degraded and too small to support viable ecosystems.
Afforestation def.
Trees are planted on land that was not previously forested (seeding or replanting)
Human causes of deforestation
Urban expansion
Infrastructure
Mining
Agriculture (local/ subsistence)
Agriculture (commercial)
Lack of laws and regulations
Poor forest management
Issues re. land rights and forest ownership
Global warming
Natural causes of deforestation
Insects, pests and diseases
Wildfires/ forest fires/ bushfires
Irregular ocean circulation patterns
Impacts of deforestation
Ecosystems are being degraded
Humans have increased extinction rate by 1000
Water quality decreasing
Flood frequency and intensity increasing
Local warming/ cooling effect
GHG emissions (10% of global emissions)
Loss of forest carbon stores (forests store 54% of total carbon pool)
Location of the Amazon Basin
6 million square km
The majority lies in Brazil, but it extends to 9 countries’ including Colombia, Peru, Ecuador, and Bolivia
