Introduction to conservation

Question 1

Anthropocene

Answer 1

time period when earth processes are influenced by human actions (1950s onwards)

Question 2

Human effects on Earth’s systems? (3)

Answer 2

Carbon cycle (fossil fuels)
Nitrogen & phosphorus cycle (fertilizers)
Ecosystem function

Question 3

Human populations …
carrying capacity?

Answer 3

populations increased rapidly after last millenia
carrying capacity = 7.7-12 billion -> can change under climate change

Question 4

demographic transition

Answer 4

L-T trend of declining birth and death rates, results in change in age distribution of population

Question 5

Developed countries

Answer 5

double problem:
- large population size
- high resource use
higher standard of living = larger ecological footprint
e.g. Americans = 5% of worlds pop., consume 24% of worlds energy

Question 6

Endless growth- how many in poverty, required?

Answer 6

= unsustainable

2 B living in extreme poverty

governmental investment and legislation required

Question 7

Anthropogenic Threats

Answer 7

• Habitat destruction and degradation
• Climate breakdown
• Overexploitation
• Invasive species

Question 8

Habitat destruction and degradation

Answer 8

• 50% inhabitable land surface been converted to human use
• many habitats degraded

Question 9

Climate breakdown- increase or decrease, what gases?

Answer 9

• increase
• carbon and carbon equivalent emissions

Question 10

Overexploitation

Answer 10

• Industrialisation of fishing - overfishing - disproportionate affect on marine organisms
• Population crashes of 99% decline - fish
• Collapse local economy and job losses
• population not recovered (Newfoundland)

Question 11

Invasive species

Answer 11

• Brown tree snake (Boiga irregularis) – accidentally introduced to Gusm in late 1940s
• increases - abundant prey and dew predators
• caused local extinction of most small native forest vertebrates
• power outages
• venomous, dangerous esp. to children
• biosecurity measures - prevent further spread to other islands

Question 12

Consequences of habitat degradation, invasive species, climate breakdown etc.

Answer 12

• Population declines
• Extinction

Question 13

Population declines- Who and average?

Answer 13

• Living Planet Index (WWF) - measure what happens to species over time
• WWF = based on trends in > 16,000 pop. representing 4000 species
• 1970 - average pop. declined by 60%

Question 14

Extinction Example

Answer 14

• Tasmanian Tiger (Thylacinus cynocephalus) - 2000 years ago, due to human pressures - hunted in Tasmania by British settlers and declared extinct in 1936

Question 15

invasive species and disease
increase or decrease? due to?

Answer 15

likely increase in importance due to global travel

Question 16

mass extinctions- number previously, loss of species, cause, after?

Answer 16

5 previous
involve loss > 70% species
most caused by rapid global warming or cooling
rapid speciation often occurs after this
<1% species extinct

Question 17

Extinction rate- increase or decrease, effect if continue?

Answer 17

increasing - matching beginning of previous mass extinctions
if continue, 75% of species will have been lost in next 240-540 years

Question 18

Examples of successful actions taken

Answer 18

Examples:
- DDT use in agriculture now banned worldwide
- SO2 emissions reduced leading to 65% decrease in acid rain
- hole in ozone layer = healing after CFC use phased out

Question 19

The greater one-horned rhinoceros

Answer 19

down to 200 individuals 20 years ago
now up to 3500