What is trophic control? Which different forms excist?

Trophic control: regulation or influence exerted by one trophic level over another within a food chain or food web top-down - (will expect negative correlation between predator and prey in a time serie) bottom-up - (will expect positive correlation between predator and prey in a time serie) wasp-waist - (induce top-down for lower trophic levels and bottom-up for higher trophic levels)