Ecology Ch 5 Interactions Section 1 Habitats and Niches

Introduction Ecosystems are a network of interactions between living things and the environment Ecosystems are a network of interactions between living things and the environment Each organism has a means of getting food, water, living space Each organism has a means of getting food, water, living space Role in the ecosystem Role in the ecosystem Approached from the evolution principle Approached from the evolution principle Adapt to change over time Adapt to change over time Ecology is the study of that adaptation Ecology is the study of that adaptation

Habitat Ecosystem can be very different Ecosystem can be very different Climate Climate Organisms Organisms Conditions Conditions Organisms must adapt to those conditions Organisms must adapt to those conditions The place an organism lives is called its habitat The place an organism lives is called its habitat Size varies with the type of organism Size varies with the type of organism

Niches Each organism had adapted to its habitat Each organism had adapted to its habitat Gathering food Gathering food Reproduction Reproduction Avoiding predators Avoiding predators Active times Active times Their role within the ecosystem is called its niche Their role within the ecosystem is called its niche Includes biotic and abiotic factors Includes biotic and abiotic factors

Niches Continued All members of a species are adapted to the same niche All members of a species are adapted to the same niche If they are different enough they are a different species If they are different enough they are a different species Anolis lizard example of two species with similar niches Anolis lizard example of two species with similar niches If two different species try to occupy the same niche it leads to competition If two different species try to occupy the same niche it leads to competition

Niche competition Competition can lead to extinction Competition can lead to extinction Competitive exclusion Competitive exclusion To avoid competition organisms will go where there is less competition To avoid competition organisms will go where there is less competition Fundamental niche- theoretical niche Fundamental niche- theoretical niche Realized niche- actual niche Realized niche- actual niche

Realized Niches Fundamental Niches

Niche Diversity Often controlled by abiotic factors Often controlled by abiotic factors Temperature Temperature Moisture Moisture Predation increases diversity Predation increases diversity Keystone predator causes the most diversity Keystone predator causes the most diversity

Robert Paine Worked with sea stars Worked with sea stars When removed the number of mussels increased When removed the number of mussels increased Number of species drops from 15 to 8 Number of species drops from 15 to 8