Topic 34 -Human Ecology

Question 1

Anthropocene

Answer 1

the current geological age in which humans have the largest impact

Question 2

what are the causes of anthropogenic mass extinction

Answer 2

habitat loss
climate change
introduced species
overharvesting

Question 3

Habitat loss

Answer 3

60% of earth is used for cropland, forestry and rangeland
many terrestrial biomes cleared for these reasons
only 2-3% has been converted to urban development

clearcutting by trawling

Question 4

Predictions of global warming

Answer 4

Increases in the average global temperature and global precipitation: temps 2-6C in next 100 years

Changes will not be evenly distributed over Earths surface -warming is expected to be greatest during the winter months in northern latitudes

Increased variability in climate: more severe storms and hurricanes, greater snowfall, increasing variability in rainfall

Question 5

Unintentionally and intentionally humans have acted as a dispersal agent for countless species

Answer 5

transporting them outside of their natural geographical ranges

some fail to survive while others flourish

freed from constraints on their native systems they establish and spread

Question 6

introduced species are often invasive

Answer 6

spread aggressively and displace other species, reducing biological diversity (richness) in locations in which they establish and become dominant

may cause extinction of vulnerable native species

Question 7

overharvesting

Answer 7

underexploited, no decline yet 20%
over exploited, awaiting recovery 28%
Fully exploited, caught at MSY 52%