Chapter 2 Biological Communities

Close, long term interactions – determine the nature of communities Habitat – where an organism lives

 Niche - the role of a species in an ecosystem  how the organism affects energy flow within the ecosystem

 Niche is influenced by several variables – temperature it prefers, the time of year it breeds, what it likes to eat, and where it finds its food

Predation  Predators and prey develop adaptations for survival Types of community interactions

 Prey adaptations – mimicry, camouflage or poisonous  Plants also avoid being eaten

Competition  Use of limited resources by 2 or more species – niche overlap - Red Maples Competition limits how species use resources

Predation and Competition  predation reduces the effects of competition.  Predation increases biodiversity  Biodiversity- types and numbers of organisms in an ecosystem  The larger the area, the more species (usually)

3 Types of Symbiotic Relationships  Close relationship when 2 or more species live together  Parasitism  Mutualism  Commensalism

Parasitism  Parasites harm the host  Ecto – outside  Endo – inside  Defenses against parasites?  Parasite adaptations for survival?

 Mutualism – both organisms benefit, ex –ants & aphids  Commensalism – 1 benefits, the other not affected