Answer:
1-Ecological succession is the process of change in the species structure of an ecological community over time.
2-Energy decreases as it moves up trophic levels because energy is lost as metabolic heat when the organisms from one trophic level are consumed by organisms from the next level.
3-A limiting factor is a variable of a system that causes a noticeable change in output or another measure of a type of system.
Step-by-step explanation: