Volcanic eruptions emit toxic gases and high heat lava flows, surrounding areas in a layer of ash. Over time, the ash breaks down and creates very fertile soils.

Which of the following statements correctly describes a volcanic eruptions effect on the surrounding ecosystem?

1. It promotes biodiversity in the short term.
2. It acts as a negative biotic selection pressure in the long term.
3. It acts as a positive abiotic selection pressure to plants in the long term.
4. It acts as a positive abiotic selection pressure to all organisms in the short term.