The study of the relationship between an organism and it's environment is called ecology

The living things in an environment are called BIOTIC factors.

The nonliving things in an environment are called ABIOTIC factors.
Examples of abiotic factors are sun light, temperature, rainfall, climate and soil conditions.

Some of these factors are LIMITING FACTORS.
They determine how many organisms can live in a given area.

Ecology concerns itself with the INTERACTION of these abiotic and biotic factors.

POPULATIONS are all the members of a given species in a given area.
Example of a population: All the blue gills in Coopers Pond. what makes a species is the ability to interbreed and produce fertile offspring. Remember they are closely related structurally.

COMMUNITIES are all the species in a given area.
Example of a community: all the living things in Frear Park.

ECOSYSTEMS are all the abiotic and biotic factors in a given area.
All ecosystems must have a constant source of energy (usually the sun) and cycles or systems to reuse raw materials. Examples are the water, nitrogen and carbon cycles.
Example of an ecosystem: an aquarium considering all the biotic and abiotic factors.

Why is there gravel at the bottom of most fish tanks?

Nutritional Relationships

Autotrophs are producers, they can synthesize their own organic nutrients.
They can do this by photosynthesis or chemosynthesis.
Tube worms rely upon the bacteria that make food at the bottom of the ocean.
The bacteria get energy and raw materials from vents on the ocean floor.
Heterotrophs are consumers, they must consume preformed organic nutrients that were synthesized by others.
Examples of heterotrophs
Saprophytes eat dead or decaying material. Examples are mushrooms and bacteria of decay.
Herbivores eat plants
Carnivores eat meat
Omnivores eat both plants and meat
SYMBIOSIS means "living together"
Clown fish and coral both benefit from living together
Mutualism both benefit from the relationship. ( legumes and nitrogen fixing bacteria ), (the lichen) (+,+)
Commensalism one benefits and the other is not effected ( remora and shark ) (+,0)
Parasitism one benefits and the other is harmed ( tapeworm and human ) (+,-)

Flow of Energy as a Pyramid

Notice that energy levels get lower as you rise up through the food chain. The most energy is at the Producer level at the BOTTOM of the energy pyramid.

Nitrogen Cycle

Carbon Cycle

Notice the relationship between aerobic cellular respiration and photosynthesis.


Most biomes, large areas of living organisms, are classified by their Climax Flora.

This means that the best adapted plants for a particular environment will be relatively stable and be successful for a long period of time. The only thing that may change this Climax Community is a drastic change in the environment such as an earthquake, flood or fire. Biomes do not begin with this stable Climax community. They first must be invaded by pioneers such as mosses and lichens. They are successfully replaced by grasses. The grasses are replaced by bushes and the bushes by trees. This Succession in our part of the country, Upstate New York , results in a Temperate Deciduous Forest. The latitude and altitude will determine which climax flora will result in the climax community.

The most stable and productive biome is the marine biome. (Salt water ocean)

Remember only about 3% of the Earth's water is fresh water. Most of this is in our Great Lakes. Fresh clean water is a most valuable asset. It is not to be squandered and wasted.

The most productive and diverse terrestrial (land) biome is the tropical rain forest.

Why is it so important to save?

El Nino and La Nina are periodic heating and cooling of the equatorial in the Pacific Ocean. El Nino's heat will cause the jet stream to speed up and strengthen. This causes high winds across the United States with relatively predictable weather patterns. La Nina's cooling weakens the jet stream and causes some unpredictable weather patterns. Some say biotic factors cause these changes. We will discover patterns in the future.

Human Impact Upon the Environment

There have been both positive and negative affects upon the world by humankind.
We have abused it by pollution. We have over reacted by exterminating many important species.
Hopefully we have realized through our mistakes that each biotic and abiotic factor plays a crucial role in the stability of our fragile world.
How safe is an automobile if you remove some bolts and try to drive it?

When you remove an organism it weakens the entire ecosystem in a similar fashion. How safe will our world be if we continue this way?

A new technique to try to lower carbon dioxide levels and global warming will be to pump the extra carbon dioxide to the bottom of the ocean.

Through legislation, we have tried to correct the mistakes of the past. This is and continues to be the most positive of all effects that humans have had upon the environment. Check out the LINKS PAGE for the latest news.

Open Ended Questions

What features must be designed into a space ship used for long term deep space travel? (include the relationship between photosynthesis and respiration)