Biology/Ecology questions

Question

1. how do human and natural disturbances affect succession?

2.how does competitive exclusion affect community structures?

3. why is the carbon cycle said to result from reciprocal processes of photosynthesis and cellular respiration?

Answer 1

1.  Humans cause fires which lead to secondary succession.  Nature causes floods, fires, volcanic eruptions, and other events which could cause primary or secondary succession- the gradual replacement of species leading to a climax community.

2.  No two species can occupy the same niche as one will invariably outcompete the other.  This leads to differing populations of organisms within a community and the possibility of organisms being active at different times of day or perhaps eating/nesting in slightly different areas.

3.  The products of photosynthesis provide the starting points for respiration.  The products of respiration are basic to the start of photosynthesis.  Look at the chemical equations of each.