biodiversity threats and protections

Question 1

how is extinction a threat to biodiversity

Answer 1

Past
99% of species that have existed are extinct
Mass extinctions – e.g., Permian event 250 million years ago
Normal rate – 1 species per decade
Present
1600–1850: 2–3 species per decade
1850–now: thousands per decade

Question 2

how is human impact a threat to biodiversity

Answer 2

HIPPO
Habitat destruction
Invasive species
Pollution
Population of humans
Overharvesting

Question 3

Land conversion for agriculture, cities
Resource extraction
Damming rivers
Bottom trawling 
Related issue: habitat fragmentation
Think back to community ecology

Answer 3

habitat destruction

Question 4

Increased transport due to increased global commerce
50,000 non-native species established in US over past few centuries
Many are useful – e.g., corn
Many are not – e.g., Asian carp

Answer 4

invasive species

Question 5

Excess nutrients  eutrophication
Bioaccumulation – chemicals accumulate in top trophic levels
Examples:
DDT and Bald eagles
Lead shot and waterfowl

Answer 5

pollution

Question 6

Increased consumption of resources

Increased use/conversion of land

Answer 6

population

Question 7

Taking more individuals from a population than can be replaced
Hunting, fishing, pet trade, medicine, and black market
Examples
Passenger pigeon
American bison: overhunting and intentional slaughter
Most fisheries are drastically depleted

Answer 7

overharvesting

Question 8

Hunting and fishing laws

Wildlife refuges

Answer 8

species protection

Question 9

Endangered Species Act (1973)

Answer 9

What it does: ID species at risk, recovery plans, landowner assistance, enforcement of protection
Categories of risk
Endangered – imminent danger of extinction
Threatened – likely to become endangered soon
Vulnerable – naturally rare or locally depleted
Successes
Peregrine falcon
American alligator

Question 10

International Union for Conservation of Nature (IUCN) (1948)
International NGO, many areas of conservation
Red List of Threatened Species
Red List of Ecosystems

Answer 10

species protection

Question 11

Convention on International Trade in Endangered Species (CITES) – 1975

Answer 11

Prohibits international sale of wildlife or wildlife parts

Success: white rhino of Africa

Question 12

Marine protected areas
Habitat restoration plans
Holistic habitat management
Protect enough habitat for viable populations
Manage at regional scales
Plan over a period of centuries
Allow for human use and occupancy at levels that do not result in significant ecological degradation

Answer 12

habitat protection