Niches and Community Interactions Learning Objectives Define niche

Niches and Community Interactions

Learning Objectives § Define niche. § Describe the role competition plays in shaping communities. § Describe the role predation and herbivory play in shaping communities. § Identify the three types of symbiotic relationships in nature.

What Is a Niche? The range of physical and biological conditions in which a species lives and the way the species what it needs to survive and reproduce.

Tolerance: the range of external conditions within which a species can survive and reproduce No survival

Competition When organisms attempt to use the same limited ecological resources in the same place at the same time. Intraspecific: between members of the same species Interspecific: between members of different species

Competitive Exclusion Principle No two species can occupy exactly the same niche in exactly the same habitat at exactly the same time.

Dividing Resources Spruce tree Cape May Warbler Bay-breasted Warbler Yellow-rumped Warbler

Predator-Prey Relationships One predator-prey cycle

Herbivory • Size • Growth • Distribution • Survival

Keystone Species A keystone species is a single species that is vital to ecosystem stability.

Symbiosis: Mutualism A relationship between two species in which both species benefit Clownfish and sea anemones help each other survive.

Symbiosis: Parasitism A relationship in which one organism lives inside or on another organism and harms it

Symbiosis: Commensalism A relationship in which one organism benefits and the other is neither helped nor harmed

Vocabulary Review Keystone species Parasitism Competitive exclusion principle Tolerance Interspecific competition Herbivory No two species can occupy exactly the same niche in exactly the same habitat at exactly the same time The ability to survive and reproduce under a range of environmental conditions One species benefits while harming another Between members of different species A single species vital to ecosystem stability An interaction in which one animal feeds on producers