Chapter 3 Communities, Biomes, and Ecosystems 3.1 Community Ecology Communities A community is a group of interacting populations that occupy the same area at the same time. Oasis

Ecological Succession Chapter 3 Communities, Biomes, and Ecosystems 3.1 Community Ecology Ecological Succession ecological succession: is the gradual replacement of one community with another as a result of changing abiotic and biotic factors.

There are two types of ecological succession— primary succession and secondary succession. Primary succession always occurs first!

Primary Succession: when a new substrate (rock), devoid of topsoil or vegetation, is deposited and colonized Begins with bare rock exposed by geological activity Pioneer species appear next

Pioneer species: species which colonize previously uncolonized land Ex. Lichen and grasses

Example: Forest Succession Rock →Grass →Shrubs →Open woods → Dense woods

Primary Succession Lava → Rock

Lichen or Grass

Grasses and Shrubs

Open Woods

Dense Woods → Stable Community

Chapter 3 Communities, Biomes, and Ecosystems 3.1 Community Ecology A community that forms in an area of exposed rock that does not have any topsoil is primary succession.

Animal succession always follows plant succession Example: Flora (vegetation): Grass → Shrubs → Woods

Fauna (animals): Pheasant → Grouse → Fox

Bog in Minnesota

Later Succession of Bog

Climax Community: The stable, mature community that results from little change in composition of species. What does Michigan’s climax community look like?

Secondary Succession: occurs after a community has been removed but the soil remains intact May occur at any point after primary succession

Usually occurs after man or nature has changed the community Example: farming, fire, flood, windstorm

Fire

New Growth After Fire

Gopher Tortoise