20 Points!! Fill in the blanks

Ecological succession is the observed process of change in the species structure of an ecological community over time. Within any community some species may become 1) __
Abundant over time, or they may even vanish from the ecosystem altogether. Other species within the community may become ___ abundant, or new species may even invade into the community from other ecosystems.

There are two types of ecological succession
- Primary ecological succession and
- ___ ecological succession
Upon what substrate does primary succession begin? (Is it soil / sediment or is it a lifeless area?)

Give 4 Examples