For example, allogenic succession that is the result of non-anthropogenic climate change can happen over thousands of years.
[4] The constant exposure to water in the intertidal zone causes the soil of a salt marsh to change over time.
During this period, the soil-salinity will also change by starting low and eventually rising to higher levels from continued seawater exposure.
Glacier forelands are another example of ecosystems that form from autogenic but also partly allogenic succession.
[5] The importance of this is estimated to be higher in earlier successional stages, regarding rock formations, slope angles and soil composition.