One of the roles of ecological succession is to allow species with different adaptations to interact. ecological succession occurs in stages, providing periods of what a overlap only for species that migrate. b separation only for species that do not migrate. c separation for all species. d overlap for a variety of species.

it's c. (to reduce the greenhouse effect/carbon gasses)

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.