Determine whether the following disturbances will be followed by primary or secondary succession.

In coastal areas, wind moves sand, blowing away or engulfing the soil, and eventually creating sand
dunes:

The introduction of livestock to an area leads to over-grazing that removes native grasses

A forest is cleared to gather lumber used for building houses:

A lava flow down the side of a volcano destroys all vegetation and eventually turns into volcanic rock
when it cools and hardens:

1.) Primary succession

2.) Secondary succession

3.) Secondary succession

4.) Primary succession

Explanation:

In a primary succession, newly developed rocks are colonized by living organisms. However, in the secondary succession, previously colonized living organisms are disturbed on a rock surface and then another form of colonization replaces it. In the given statements, first and fourth option are the examples of primary succession because, here, new sand dunes are being created followed by colonization of new form of life.

All other options are example of secondary succession because,