Biology 3445F Lecture Notes - Lecture 8: Network Theory, Emergence, Herbivore
Document Summary
* discussion of 2 species interactions along a continuum of interaction types with a focus on how these interactions affect community structure* In real communities, each species interacts with several others direct interactions can give rise to indirect interactions. Takes place when one organism (the predator) consumes another (the prey) Includes total consumption of other organism for nutrients (herbivory, parasitism) Both directly and indirectly: top-down effect of predators on both consumers (direct) and producers (indirect, cascading effect through > 1 trophic level. Unlike predation, in which the whole organism is destroyed, plants often survive grazing by a herbivore: can result in protective adaptations e. g. thorns, secondary metabolites (bad smell/taste) costs energy, still an overall negative effect. A parasite is physiologically dependent upon its host for nutrition. While the host is negatively affected by the loss of nutrients to the parasite, parasitism rarely leads directly to the host"s death.
