* Volcanic eruptions: When volcanoes erupt, they can create new islands or land masses made of cooled lava. This fresh rock is devoid of any soil or life, making it a prime candidate for primary succession.
* Glacier retreat: As glaciers melt and retreat, they leave behind bare rock and sediment. This freshly exposed land can then be colonized by pioneer species.
* Sand dune formation: Windblown sand can accumulate and form dunes, creating new landforms that can support life.
* River deposition: Rivers can deposit sediment at their mouths, creating new land that can be colonized by plants and animals.
Essentially, any process that creates a new, barren environment with no pre-existing soil or life forms will trigger primary succession.
