Chapter: 3.1 C OMMUNITY E COLOGY

 All living organisms are limited by factors in the environment  A biological community is a group of interacting populations that occupy the same area at the same time

 Limiting factors are any abiotic or biotic factors that restricts the numbers, reproduction, or distribution of organisms  Factors that restrict the growth of one population might enable another to thrive

R ANGE OF T OLERANCE  Any environmental factor, there is an upper limit and lower limit that define the conditions in which an organism can survive  Example: steelhead trout live in cool, clear coastal rivers and streams.  Ideal range of water temperature is between 13 and 21 degrees Celsius  Temperatures above 25 degrees Celsius the trout will die

E COLOGICAL S UCCESSION  The change in an ecosystem that happens with one community replaces another as a result of changing abiotic and biotic factors is ecological succession  The establishment of a community in an area of exposed rock that does not have topsoil is primary succession

 A mature community can eventually develop from bare rock, this is called a climax community  After a flood, fire or other disturbance new species of plants and animals that occupy the habitat is considered secondary succession

T ERRESTRIAL B IOMES  Weather and latitude have major effects on terrestrial biomes  Tundra  band below the polar ice caps  Boreal forest  band below the tundra  Temperate forest  southeaster Canada, eastern US  Woodland  Mediterranean, western coasts of US and south Africa and Australia  Grassland  US, South America, Asia, Africa

 Desert  every continent except Europe  Tropical Savanna  Africa, S. America and Australia  Tropical seasonal forest  Africa, Asia, Australia  Tropical rain forest  Central & South America, Australia, Africa

A QUATIC ECOSYSTEMS  Freshwater ecosystems  Rivers and Streams  Lakes and Ponds

T RANSITIONAL A QUATIC E COSYSTEMS  Wetlands  marshes, swamps  Estuaries

M ARINE E COSYSTEMS  Intertidal Zones  narrow bands where the ocean meets land  Open ocean  Coastal ocean  Coral reefs

M OVIE T IME  Energy Flow in an Ecosystem Energy Flow in an Ecosystem  Redwoods Redwoods