How do living things alter the biotic and abiotic environment to cause the process of succession?

i really need it to study

Our living species migrated to the “environment”, established in the area, and then it will increase by number. After that we have competition and co-action resulting in the survival of fit individuals and the elimination of unfit individuals from the ecosystem.

Land marks is ruler of the world i just wanna let you kno that you are really smart