Both primary and secondary succession begin with pioneer species that

The different zones or region on the planet may some times suffer great distress in creating the best ecologically suitable environment for all the living being, as there are various factors that come in to play such as the soil moisture, presence of humidity and moisture inside the air, and many other factors.Both primary and secondary succession begin with pioneer species that  enriches the soil and make it able for the living beings to develop itself in it and provide a suitable environment for life to flourish more frequently.    

Explanation:

But, the two steps of successions involves the primary and secondary stage in a given form or procedure. As, the primary succession occurs inside the region which is left abundant due to some reason and there is less for the living being to gain from, so the land then faces the primary succession and many micro organism play a vital role in making the whole situation much better for the living beings.And the lithosphere is highly influenced by the actions of different associations that are formed for the growth of the land mass as a whole.Now, the secondary succession involves the covering of that specified piece of land by the presence of the specific number of species which would provide more diversity to the land mass and create a better ecological system for the living beings to live inside it.