How would soil fertility likely change during the early years if primary succession

The answer is: Soil Fertility "Gradually Increase" during the early years of primary succession

Primary succession begin when an area still does not have any form of soil to begin with. Overt time, organisms such as algae,   lichen,  and fungi start to influence the environment in that area.  Gradually, rocks started to be transformed into soils and these early organisms started to gather various nutrients from around them. This will gradually increase soil fertility during early years of primary succession.

yes, it is pretty much the same thing, which is cool. : )

when you rub, you also apply pressure, that pressure can urge the poop to come out. i think that when your rubbing, you also might be slightly breaking it up and that can further fill the stomach.