Ecosystems

What is ecology?

Ecology- the scientific study of interactions between organisms and their environments, focusing on energy transfer

• It is a science of relationships.

EC0- House or Home -OLOGY- The Study of

What do you mean by environment?

The environment is made up of two factors:

Biotic factors- all living organisms inhabiting the Earth

Abiotic factors- nonliving parts of the environment (i.e. temperature, soil, light, moisture, air currents)

Organism

Population

Community

Biosphere

Ecosystem

Organism- any unicellular or multicellular form exhibiting all of the characteristics of life, an individual.

•The lowest level of organization

Population-a group of organisms of one species living in the same place at the same time that interbreed and compete with each other for resources (ex. food, mates, shelter)

Community- several interacting populations that inhabit a common environment and are interdependent.

Ecosystem- populations in a community and the abiotic factors with which they interact (ex. marine, terrestrial)

Biosphere- life supporting portions of Earth composed of air, land, fresh water, and salt water.

•The highest level of organization

Trophic LevelsFood chain- simple model that

shows how matter and energy move through an ecosystem

Food Chain -a linear path of energy

transfer

Trophic Levels

Food web- shows all possible feeding relationships in a community at each trophic level

•Represents a network of interconnected food chains

Food chain Food web(just 1 path of energy) (all possible energy

paths)

CYCLES

• Carbon CycleThe movement of carbon, in its many forms, between the biosphere, atmosphere, oceans, and geosphere is described by the carbon cycle.

Can you identify means in which carbon is absorbed?

Can you identify means in which carbon is released ?

Carbon Cycle Animated

Nitrogen is essential for many biological processes; it is in all amino acids, is incorporated into proteins, and is present in the bases that make up nucleic acids, such as DNA and RNA. In plants, much of the nitrogen is used in chlorophyll molecules which are essential for photosynthesis and further growth

NITROGEN CYCLE

ANIMATED

Just like water and carbon cycle through ecosystems , toxins do as well.

However, while energy decreases as it moves up the food chain, toxins increase in potency. This is called biomagnification.

• Nitrogen (N) is a necessary component of amino acids and nucleic acids. How do animals obtain useable nitrogen in the nitrogen cycle? – A. Animals obtain nitrogen from breathing the air. – B. Animals absorb nitrogen compounds through their

skin. – C. Animals take in nitrogen by digesting proteins and

nucleic acids. – D. Animals eat the roots of plants containing nitrogen-

fixing bacteria.

1.

• The organism shown in Figure 2-12 is involved in which type of symbiosis? A) commensalism

• B) parasitism

• C) predatorism

• D) mutualism

2.

• Which of the following can increase the amount of carbon dioxide in the atmosphere?  

• a.  industrial burning of fossil fuels   

• b.  deforestation   

• c.  automobile exhaust   

• d.  all of these answers are correct 

3.

• Over millions of years, the remains of ancient organisms gradually turn into fossil fuels. Which of the following is a by product given off when humans burn these fossil fuels? – A. hydrogen (H2) – B. oxygen (O2) – C. methane (CH4) – D. carbon dioxide (CO2)

4.

• A volcano in a mountainous, wooded region erupts, spewing tons of ash and destroying the forested area around the volcano. If the volcano remains dormant during the next 1000 years, what will probably happen? – A. The mountains will erode and remain without

life. – B. The area will remain unchanged, covered by

volcanic ash. – C. The area will be repopulated by trees,

eventually becoming a forest again. – D. The area will turn into a completely different

habitat, such as desert or plains.

5.