Question

Describe the Dynamic Equilibrium Model and the Menge-Sutherland Model

Answer 1

DEM (dynamic equilibrium model) predicts that the effect of disturbance in the community due to predation and other factors depends on the level of productivity. This model is supported when biodiversity is measured as species richness, but predict evenness to increase with increasing disturbance, for all levels of productivity

Menge and Sutherland predicted that in physically benign habitats:

(1) community structure will be most strongly affected be predation, - predation can reduce the number of the preys and thus affecting the overall community structure.

(2) the effect of predation will increase with a decrease in trophic position in the food web,- lower animals or consumers are large in number and are mostly preys for higher members in the food chain

(3) trophically intermediate species will be influenced by both predation and competition- the members of the upper trophic level will be a predator for the intermediate trophic level member and there would also be a large competition between its own members.

(4) the competition will occur among prey species which successfully escape consumers- because these preys are free and thus they start competing with each other for all the resources like mate, shelter and food.