How do human activities lead to secondary succession?
Humans can cause destruction to ecosystems and initiate secondary succession.
Primary and Secondary succession happen when there is little to no life in a certain area. Primary succession often happens when lichens populate an area, making it habitable for mosses, mosses making it habitable for grasses and beginning to form dirt, grasses making it habitable for small plants and ferns, making it habitable for shrubs, making it habitable for small trees, making it habitable for trees.
This is a great diagram for primary succession.
Now for secondary. Secondary succession happens when an ecosystem is destroyed, but the dirt and smallest plants still remain. Secondary succession begins when grasses and mosses begin to populate an area, and the same steps begin to take place that take place in primary succession. The most important thing to remember is that it doesn't start over.
This is a great diagram for secondary succession.
So how does human activity cause secondary succession to take place? Well, humans cause a lot of destruction to the natural world, through deforestation, starting forest fires, farming, and building things. So when we destroy the environment, we allow a new environment where secondary succession begins to take place. It is still slow, and habitats take hundreds of years to rebuild, and often are nothing like the habitat before it. This is why the effort to conserve the environment is very important if we want to keep living on this planet.