Ecology Ecology is the study of the interactions

Ecology

Ecology is the study of the interactions between organisms and their interrelationships with the environment.

Ecology n Organisms Environment

Ø No organism exists as an entity, separate and distinct from its environment. Ø All living organisms are dependent upon other living things as well as dependent on the nonliving environment.

Ecological Organization

Arrange these from largest to smallest Community n Population n Biosphere n Ecosystem n Answer: Biosphere Ecosystem Community Population

Biosphere is the portion of the earth in which life exists – oceans, land & sky.

Ecosystem is the living community and the physical environment functioning together as an interdependent, selfsufficient, and relatively stable system.

* The ecosystem is the structural and functional unit studied in ecology

Community All the plant and animal populations of a given area make up a community.

Population is all the members of a species living in a given location. Ex #1: all the gray squirrels living in a forest Ex #2: All the dandelions growing in a field

species A group of organisms capable of interbreeding and producing fertile offspring

The Liger http: //www. youtube. com/watch? v=CD 6 vphe. Uo. PE

How is the meaning of the word “population” in Biology different from its everyday (common) meaning? In Biology, a population is a smaller group than a community

SUN (radiant energy) What do the arrows represent? Energy A Food Chain

An ecosystem is a self -sustaining unit if the following requirements are met:

Characteristics of Ecosystems 1) constant source of energy. 2) organisms that can store this energy into organic compounds

3) A flow of energy from one population to another - food chains, food webs 4) cycling of materials between the organisms and their environment.

A. Ecosystem Structure & Function Ø An ecosystem involves interactions between abiotic (nonliving) and biotic (living) factors.

Abiotic Factors The abiotic environment includes physical (non-living) factors which affect the ability of organisms to live and reproduce. The abiotic factors include:

• gases - O 2, CO 2, N 2 • temperatures • moisture • substratum • inorganic substances - minerals • light • p. H

Each of these factors may act as a limiting Factor determines the types of organisms which may exist in that environment. Examples of limiting factors include:

• The amount of available water determines the kinds of organisms that can live in a desert.

• The low temperature of regions at high latitude or altitudes. • The salt concentration in the oceans and seashore regions.

Some species of fish, shellfish, and other marine species would die in freshwater due to an imbalance of water pressure in their tissues.

• Some plants live well on a forest floor under tall trees, but would not do well in an open field due to the increased intensity of light.

Biotic Factors are all the living things that directly, or indirectly, affect the environment.

Ø Thus, the organisms, their presence, parts, interaction, and wastes, all act as biotic factors. Ø Biotic factors interact in many ways such as in nutritional relationships and symbiotic relationships.

Nutritional Relationships involve the transfer of nutrients from one organism to another.