Ants, flies, mosquitoes, and cockroaches all form living biological communities, necessary components of an ecosystem.

A.    The earth’s life-support systems maintain entire ecosystems.

B.    Eco-systems, influenced by physical and chemical components, support bio-diversity while connecting food webs and energy flows.

1.     Law of tolerance

2.    Producing or consuming organisms

3.    Biodiversity’s importance

4.    Food webs and matter cycling

C.    Biogeochemical cycles affect the biosphere as well as the earth’s ecosystems

D.    What are the connections between ecosystems and sustainability?


4-1  The nature of ecology

Ecology studies the interaction of organisms with each other and with their non-living environment. 

A.    Eukaryotic and prokaryotic organisms are classified into species which reproduce sexually and asexually.

B.    Populations and their habitats form biological communities which eventually establish an ecosystem. 


4-2  Connections: The earth’s life-support systems

The earth’s life-support systems are protected by several layers which help sustain life through energy from the sun, cycling of matter, and gravity


4-3  Ecosystem concepts and components

Biotic and abiotic components make up ecosystems which are distinguishable by their chemical and physical characteristics.

A.    Biomes and aquatic life systems

B.    Physical and chemical environments

1.     Range of tolerance and law of tolerance

2.    Limiting factor(s)

C.    Ecosystem biological components

1.     Producers/autotrophs

2.    Consumers/heterotrophs

D.    Biodiversity: genetic, species, ecological, functional


4-4  Connections: Food webs and energy flow in ecosystems

Ecosystem connections support and enhance food webs and energy flow.

A.    Food chains and food webs

B.    Energy flow in an ecosystem


4-5  Primary productivity of ecosystems


4-6  Connections: Matter cycling in ecosystems

Nutrient cycles composed of various carbon, oxygen, nitrogen, phosphorus, and hydrologic cycles are cycled through the non-living environment.

A.    The biosphere and nutrient cycles

B.    Human activities and the nutrient cycles


4-7  How do ecologists learn about ecosystems

Knowledge about ecosystems is acquired through field research, laboratory research and system analysis.


4-8  Connections: Ecosystem services and sustainability

The two basic principles of ecosystem sustainability are renewable solar energy and recycling of chemical nutrients.

Outline for Chapter Five
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Glossasry for Chapter 4