Module 9

Question 1

4 threats to biodiversity

Answer 1

1. Habitat loss/ destruction
2. Over exploitation/ over harvesting
3. Intro new species
4. Global changes

Question 2

Causes habitat loss/ destruction

Answer 2

• deforestation
• habitat fragmentation
• forest fires
• mining

Question 3

Dodo

Answer 3

Overexploitation: Over hunted by sailors

Question 4

Passenger pigeon

Answer 4

• 40% overhunted
• habitat destruction
• Martha died 1914

Question 5

Giant tortoise

Answer 5

Lonesome George died 2014

Question 6

Overfishing Atlantic cod

Answer 6

-1992 collapse

Question 7

Lead to fishery collapse

Answer 7

• exploitation
• disturbance
• insufficient productivity
• no other profitable species

Question 8

Long line fishing

Answer 8

Super trawlers: 25-30 tons

Question 9

Trophic cascade

Answer 9

Change of eco systems

Question 10

Moratorium

Answer 10

Fishing for cod

Question 11

Invasive species

Answer 11

Deliberate/accidental movement of species causing greater risk local extinction

Question 12

Argentinian ant

Answer 12

Linepithema humile

• low intraspecific competition
• large colonies
• Dominant

Question 13

Red fox

Answer 13

Vulpes vulpes

• sport to pest
• over 7 billion
• threat biodiversity
• extinction small mammals/birds
• threaten livestock

Question 14

European rabbit

Answer 14

Oryctolagus cuniculus

• 1778 brought to Australia
• 1859 Thomas Austin released 13
• 150 million feral
• pest: crop damage
• increase impact drought/fire

Question 15

Cane toad

Answer 15

Rhinella marina (Bufo marinus)

• diverse diet
• native south Central America
• 1935 unsuccessfully introduced for cane beetles (insufficient shelter, bad climbers, eat other stuff)
• poisonous skin: decline native reptiles

Question 16

Stephen’s island wren

Answer 16

Xenicus lvalli

• 10 flightless pairs
• eaten by Tibbles the cat

Question 17

Global changes

Answer 17

• release toxins
• gh gas
• global warming

Question 18

Toxins

Answer 18

Pesticides

• decrease biodiversity
• impact water, soil, air

Question 19

Phosphorus in Great Lakes

Answer 19

• Runoff = eutrophication (enrichment minerals/nutrients in water)
• nuisance algae leads to hypoxia (oxygen depletion)

Question 20

Habitat loss example

Answer 20

Ex. 93% coral reefs damaged by humans (50% disappear 30-40 years)

Question 21

Effects global warming

Answer 21

• changes species distribution

- affects arthropod metabolism, reproduction, survival

Question 22

Endangered species example

Answer 22

Tasmanian devil (Sarcophilus harrissi)

• largest carnivorous marsupial
• nocturnal
• scavenger
• consumes bones (returns N,P to soil)
• wiped from mainland by dongoes (Canis lupus dingo) now endemic to Tasmania
• endangered by DFTG killed 90%
• eat less often = small impact on small mammals

Question 23

Effect of population decline

Answer 23

Restructures food webs

Question 24

Conservation biodiversity ex

Answer 24

Aussie ark

• 390 devils born
• released in sanctuary 2020

Question 25

Extinction opposite to speciation