Question

5 – community ecology: ecological succession
learning objective: differentiate between primary and secondary succession.
which of the following statements would be an observation of primary succession?
a.) \look at the plants that have regrown on this mountain since the volcanic eruption two decades ago.\
b.) \the weeds have taken over my neighbor’s pasture ever since that fire came through.\
c.) \i’ve noticed several species of lichen growing on rocks exposed by a melting glacier.\
d.) \i can’t believe how quickly the shrubs regrew after last summer’s tornado.\

Explanation:

Primary succession occurs in an area where there was no previous soil or life - starting from bare rock or other barren substrates. Lichens growing on rocks exposed by a melting glacier is an example of primary succession as it starts in a newly - exposed, lifeless area. Options a, b, and d are examples of secondary succession which occurs in an area where soil and some life already existed before a disturbance.

Answer:

c. "I've noticed several species of lichen growing on rocks exposed by a melting glacier."