Ch 12- Resources And Human Impact Flashcards
(29 cards)
What are the causes of desertification?
Over planting
Over grazing
Tree cutting
–occurs mostly in semiarid areas
How do humans modify forests?
Cut down trees
Turn into farms
Pollute forests
Build building/ houses
Costs associated with mineral exploitation
Economic costs---- -restoration costs a lot Energy cost------ Labor Reclamation Power Environmental cost---- -Acid drainage -polluted water -altered habitats + environments
Why do nations trade mineral resources
Lack of necessary resources
- economic interests
- political interests
Renewable vs nonrenewable resources
Renewable
-formed or regenerated by NATURAL processes
Nonrenewable
- not replaced by natural processes
- -iron ore
- -fossil fuels
How do humans cause extinctions
- habitat destruction
- disruption of animal/ plant life
- pollution
- over hunting
Human impacts over time changed?
Early
- hunt to survive
- not much pollution
Today
- pollution from cars, factories, everything
- humans suck
What is pollution
Any additional MATTER or ENERGY that degrades the environment
How do humans impact the biodiversity of an ecosystem?
Humans take over an area
- no place for animals/ plants
- constantly building in areas
Change in forest types 1981-1990
Tropic
-3.8%
Temperate
+.0% gain
How does logging change the forest environment?
- more flooding
- destruction of habitat
- –clear cutting is the worst
Logging methods
- clear cutting
- –entire area cut down
- patch work clear cutting
- small patches of clear cut among forested areas
- select harvesting
- -cut individual trees
Why are environmentalist concerned about tropical desertification?
Because they are
What are rangelands and how are they used?
Land that is not intensively managed and is used for LIVESTOCK grazing
Positive and negative effects of using rangeland?
Good
- free uses
- not much energy required
Bad
-desertification (semiarid land converted to arid land/ deserts)
Positives and negatives effects of harvesting limits for the fishing industry?
Good
- maintain fish population
- balanced environment
Bad
- loss of revenue
- overfishing
Humans alter freshwater ecosystems?
- overfish
- pollute
- introduction of invasive species
- habitat destruction
What is habitat management?
Habitat modifications made to enhances that success of species
Predictor/competitor control?
- though it would increase game species if the predator was taken away
- or introduce more completion
- -does not really work though
What factors are used to determine a species probability of EXTINCTION?
-population density
-area size
Specialized niche
-low reproductive rates
-birth and death rates
Why worry about extinction?
- species help us
- play key roles in the sustainability of an ecosystem
Endangered vs threatened species?
Endangered- such small number, they are endangered of becoming extinct
Threatened- could become extinct if critical environmental factors are changed
How is fires used for forest management?
- Pin cones need heat to open
- less dead/old growth
- small, controlled burn to prevent large burns
Types of miming
Strip- above ground
contour- cut into mt. Side
Shaft- down, down, down, down, down
Mt. Top removal- bast it off!!!