Ecology: 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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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

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

Energy Transfer  Food Chains  Food Webs  Energy Pyramids