Ecology: an introduction

The study of the interactions that take place among organisms and their environment

Biosphere The part of Earth that supports life Top portion of Earth's crust (lithosphere) All the waters that cover Earth's surface (hydrosphere) Atmosphere that surrounds Earth

Ecosystem All the organisms living in an area and the nonliving features of their environment Biotic – living Abiotic – nonliving

Biotic Biotic – living Plants Animals Single celled organisms Fungi

Abiotic Abiotic – nonliving Water Air Soil Temperature Sunlight

Parts of an Ecosystem

Population All the organisms in an ecosystem that belong to the same species (biotic)

Community All the populations in an ecosystem (biotic)

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The place in which an organism lives Habitat The place in which an organism lives provides the kinds of food and shelter, the temperature, and the amount of moisture the organism needs to survive

Niche The specific role that an organism plays in its ecosystem

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Competition Food Space

Competition Competition caused by population growth affects many organisms, including humans Limits population size

Limiting Factor Anything that restricts the number of individuals in a population. Includes living / biotic and nonliving / abiotic features of the ecosystem

Carrying Capacity The maximum number of individuals of any species that can be supported by a particular ecosystem on a long-term basis

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