Lecture 5 - DA Flashcards
What are heathlands predominated by?
Shrubs, may have grass.
Which animal populations are destroyed by fierce fires?
Any animal that isnt capable of flight. Burrowing animals may survive if deep enough.
What is the current rate of species extinction comparable to? What 4 factors is this attributed to?
Past mass extinction events
- population growth
- agricultural expansion
- overexploitation of resources
- competition with introduced invasive species
Define biological diversity.
variety between all species of plant, animal and microbes in the ecosystem in which they live and interact.
Is more diversity better?
Thought to be so, but not enough evidence.
What is accelerated by diversity loss?
Habitat loss.
What is an ubiquitous species?
Species found over wide geographical areas in many ecosystems/countries
What is an endemic species?
Species found in one geographical area
Between an ubiquitous and an endemic species, which is more vulnerable to extinction?
Endemic, as theyre only found in one area.
How does diet affect extinction vulnerability?
Fussy eaters are more vulnerable.
Define critically endangered.
50% chance of extinction within 10 years or 3 generations.
Define endangered.
20% chance of extinction within 20 years or 5 generations.
Define vulnerable.
> 10% chance of extinction within 100 years.
What are 3 features of threatened species?
Often highly endemic
Low competitiveness
Are fastidious, with specific requirements
What is the minimum viable population (MVP) for animals? What about plants?
Animals - 1k
Plants - 10k
With breeding programs for plants and animals, is inbreeding considered a serious problem?
In animals, is serious and can lead to deleterious mutations.
Not a problem in plants.
How does inbreeding become a problem?
In animals, it reveals deleterious recessive alleles. Individuals will eventually become homozygous.
Each subsequent generation has less survival fitness than the previous.
Order the following by the size of reserves required;
Large herbivore, large carnivore, small herbivore.
Small Small herbivore Large herbivore Large carnivore Large
Between plants and animals, which needs more reserve space?
Animals.
Why do carnivores need large reserve areas?
They hunt herbivores, so they need large spaces.
Many animals need large reserves, why is this a problem? What happens as a result?
Difficult to get the area required from the government. Typically reserves are fragmented and need to be close or linked together.
What kind of reserve is better, round or elongated? Why?
Round. Results in a smaller border between the reserve and a civilised area, and lessens the transitional edge habitat.
Why are many species endangered? Why is this a problem for reintroduction?
Habitat destruction. Breeding is useless if theres no habitat left. Restoration is also needed.
Where are Australian alps found? What percentage of the continent does it make up?
Only in southeast Australia, making up 0.25% of the continent.
