Quiz 4 Flashcards
(50 cards)
Why were cane toads introduced to Queensland?
To control cane beetles
Why do cane toads not control cane beetles?
The sugar cane fields where the beetles live so not have enough cover for cane toads
What makes cane toads so invasive?
- early maturation
- high fecundity
- toxicity and large size (limits predators)
- trophic generalist (abundant resources)
What four factors contributed to the cane toads’ successful invasion in Australia?
- no predators
- no competitors
- abundant habitat
- abundant resources
How many biogeoclimatic zones are in BC?
14
Describe diversity in early, mid, and late stages of succession
Early: low diversity, mainly generalist, r- selected species
Mid: high diversity, both r and K selected species
Late: low diversity, mainly specialist, K-selected species
What determines future species composition?
- physical habitat
- prior residents
- chance
Prior residency effect
Each species changes the environment, which determines its suitability for colonization by other species
Clements theory of succession
Superorganism: communities are highly organized and lead to a final state of equilibrium
Gleasons theory of succession
Individualistic: communities are random assemblages of species which respond individually to environmental changes; this is the correct idea!
What are the two theories of succession?
Superorganism (Clements) and individualistic (Gleason)
What changes throughout the stages of succession?
Energy flow, patch dynamics, competition
What do disturbances do to an ecosystem?
Move the community back to an earlier stage of succession
What happens to a community after a disturbance?
It continues through the stages of succession. It may continue along its previous path or it may develop in a different direction
Primary succession
A community forms from abiotic conditions, such as after a volcanic eruption or a glacial retreat
Secondary succession
A community is moved back to an earlier stage in succession, but still contains organic material. For example, secondary succession happens after a fire, drought, or harvest
Assembly rules
Patterns which dictate the probability of a specific species colonizing an area, based on order of arrival
What is the function of a keystone species?
Keystone species help to maintain weak links and keep the ecosystem in a mid successional state
How do you small world networks benefit ecosystems?
They give it higher resilience, because the loss of one node does not prevent the whole system from functioning. Also, a small World network is the most efficient way to transfer energy or matter through a system
What is the keystone species in a Gary oak ecosystem?
Humans. Native American communities use controlled burns to control disturbance in karaoke ecosystems and preserve them in a mid successional stage
What are four measurements of ecosystem health?
Number and relative abundance of species, trophic web architecture, keystone species, interaction strength
Galileo
Provided evidence to support the theory of a heliocentric universe. This went against the churches authority and the idea of a geocentric universe. Galileos ideas were accepted because the argument was about how the universe is structured and not why, so the church could still maintain its power
Aquinas and Aristotle
Aquinas rewrote Aristotle’s ideas of a nested hierarchy which provided an idea for why things happen in nature. This philosophy was accepted by the church at the time.
Wren and Halley
Wanted to see if a connection could be made between the inverse square law of attraction in the elliptical orbit of planets. Encouraged Newton to write and publish the Principia, which was important to the Enlightenment
