Which best describes the ecosystems on earth? a. earth has mostly rainforest ecosystems. b. separate ecosystems can affect each other. c. ecosystems do not interact with each other. d. there are very few types of ecosystems on earth.

Separate ecosystems can affect each other.

B. Separate ecosystems can affect each other

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.