Chapter 47-1

Earth a Living Planet

 Ecology is the study of the interactions of organisms with one another and with their physical surroundings.  The biosphere includes all areas of the land air and water on earth as well as the animals that populate those areas.  The earth has many ecosystems which consists of a given areas physical features (abiotic factors) and living organisms (biotic factors).

 This is called ecological succession. Fig. 47-3.

 Example: A pond fills up with silt and fallen leaves, over a period of time the pond turns into a marsh and then into dry land.

A community refers to the organisms living together in an ecosystem. A new community can replace an existing community over time.

 Pioneer species colonize places where living communities existed before. Examples: lichen on bare rock.

 Succession often leads to a stable collection of organisms called a

climax community.