3questions/ 15 points. in advanced.

I believe these are the answers:
1.) a drought hits an area and there is less available water.
Can also be small frequent brushfires that thins competition for pine trees.
2.) the habitat of a species within a community resulting from clumping.
3.) regression
Let me know if these are right, hope this helps you!!

The answer is option b.

If the experiment was perfomed more then once and you get the same results