Principles Of Ecology Quiz #3

Question 1

Explain the balance of sea urchins in PNW

Answer 1

Keeps brown algae under control but they eat kelp roots. Sea otters sea the urchins and keep populations in control.
Kelp forests have many functions including habitat, water break, diversity, produces carbon in ocea

Question 2

Why are parrotfish important to ecosystems

Answer 2

Eats algae

If parrot fish is overharvested leads to reduced biodiversity and less ecosystem resillience

Question 3

Why are sea otters keystone species

Answer 3

Keep urchin populations in control and prevent them from collapsing kelp forest ecosystem

Question 4

Why are sea stars a keystone species

Answer 4

Preys on urchins, mussels, and other shellfish that have no natural predators - functional redundancy

Question 5

Primary vs secondary success

Answer 5

Primary begins in an area where no soil is present. Secondary is when soil is already present

Question 6

What can influence ecological succesion

Answer 6

Site condition, interactions of species present, availabiilty of seeds or weather
Some factors help some problematic

Question 7

3 factors that promote stability and coexistence o predator/prey

Answer 7

1. Spatial heterogeneity (pockets for escaping)
2. Prey evolution of behaviors
3. Alternate prey - provides refuge