deforestation Flashcards
(31 cards)
Resons why forests are important
-contain 50% of the world’s plants and aniamls
-improves air quality (absorbs CO2)
-recreation and torism (engaging in actities)
-provides many sources of food(coffee, bananas, nuts and fruit)
Facts and stats
-forrest cover approx. 31% od the world’s surface area
-annual loss of 10 million hectares
-350 million people live within or close to forests
-large tracts of the world’s remaining forests are contained within national parks
-rates of deforestation have slowed
Spatial distribution of forests
-Russia contains the largest proportion od the world’s forests at 20%
-Australia contains 3% of the world’s forests
Natural characteristics of forests - Forest
natural land cover covering at least 0.5 hectare dominated by trees having a height of at least 5m and a crown cover of at least 10%.
Natural characteristics of forests - Biome
a biome is a large naturally occurring community of flora and fauna occupying a major habitat, e.g. forest or tundra
Natural characteristics of forests - Primary forests
intact or old growth forests are forests that remain in virtually pristine condition, containing the full array of native species. Make up 36% of forests and declining.
Natural characteristics of forests - Secondary forests
or regrowth forests or regenerated forests consist of native species but they have been disturbed by human activities, or humans have intervened in their development, such as through replanting. Make up 57% of forests.
Natural characteristics of forests - Plantations
are a monoculture (only one plant type) of native or non-native trees planted for the commercial production of a particular species (eg rubber, blue gums, pinus radiata etc) or for environmental services such as environmental control (excluding tree food crops and crops such as oil palm). Make up 7% of forests.
Deforestation
The long-term reduction of tree canopy cover to below 10-30% of its original cover (depending on the type of forest).
Forest degradation
Forests modified by human activities (selective logging, replanting, shifting cultivation & wood fuel collection. More than 10-30% of forest remaining.
(Deforestation- less than 10-30% remaining)
Fragmentation
Clearing of pockets of land mostly for roads, leaving pockets of forest, over time, edges of become degraded and pockets become too small to support viable ecosystems.
Afforestation
Trees are planted on land that was not previously forested (seeding or replanting)
why are Forests are cleared and modified?
- As a source of wood & non-timber products.
- To change the land cover to accommodate for- settlements, farms, dams & mines
- As a result of natural disasters (drought, fire & landslides)
Natural Process Causing Global Deforestation
- Insects pests & diseases
- Wildfires
-Irregular ocean circulation patterns - Natural climate change
Insects pests & diseases causing deforestation
Affect less than 2% of forests annually (primarily in temperate and boreal zones). E.g. Noth American mountain pine bettle devasted more than 11 million hectares in Canada in Western USA.
Wildfires causing deforestation
Affect about 3% of forests each year (dry temoerare & tropical regoins).E.g. Black Summer fires un Australia. Australia’s temperate forests regenerate after wildfire and even dependcon it for regrowth, however some forests are very sensitive to fire and can be devasted
Irregular ocean circulation patterns causing deforestation
El Nino Southern Oscillation and the Indian Ocean Dipole and their influence on extreme weather such as drought & tropical storms affect lass than 0.5% of global forest cover annual.
Natural climate change causing deforestation
Over many thousands of millions of years causes deforestation when temperature, evaporation or precipation extremes reduce forest growing seasons or when wildlife becomes more common
Human activity Causing Global Deforestation
- Agriculture, logging & wood fuel collection
-Projects to improve infrastructure
-Agriculture sector
Subsidies - Difficulty to enforce laws & regulations
- Poor forests management
in LICs & NEEs - land rights & forest
ownership issues - War and civil disruption
- Pursuit of economic
development - Global warming from
human activity
Agriculture, logging & wood fuel collection causing deforestation
Agriculture= 73% of deforestation, Logging= 19%, Wood fuel collection= 6%
Projects to improve infrastructure causing deforestation
Mines, dams, transport and rural settlement facilities. Roads and rural settlements increases accessibility to forests. E.g. Trans-Amazonia highway in Brazil.
Agriculture sector
Subsidies causing deforestation
Supported by government subsidies to promote food security. May enhance economic benefits of farming, fuelling deforestation.
Difficulty to enforce laws & regulations causing deforestation
Enforcement difficult due to remote and isolated locations of forests (requires money and workforce to enforce). Lack of enforcement leads to illegal logging.
Poor forests management
in LICs & NEEs
causing deforestation
LICs & NEEs lack workforce capacity to enforce existing laws & corruption exists due to high value of forest products. Rapid & wasteful exploitation of forests has occurred. Illegal logging & clearing for agriculture= US$51-$152 billion/year (mainly in Indonesia & Brazil).
