Question

Which disturbance would result in primary succession?
harvesting wheat by using a combine harvester at the end of the growing season
controlled burning to stimulate the growth of forest trees such as sequoia
the formation of Surtsey, a volcanic island off of the southern coast of Iceland
the effect of a large herd of elephants on the grasses and shrubs in an area

Answer 1

the formation of Surtsey, a volcanic island off of the southern coast of Iceland

Answer 2

the formation of Surtsey, a volcanic island off of the southern coast of Iceland
-- primary succession is when something builds when nothing was there previously, secondary is when it rebuilds for example a fire