Intro to ecology

What is ecology?

• The study of interactions b/t organisms and the living and nonliving components of their environment.

• What kinds of living and nonliving things do we have in our environment?

Organisms and their environments

• All organisms interact not only with living things but with nonliving things as well. They cannot survive without that relationship.

• This is called interdependence. • For instance: you could not survive without

plants and other microorganisms that produce oxygen. In return they have to have carbon dioxide to do photosynthesis which produce oxygen.

Effects of interdependence

• Even though interdependence is a good thing. It can also cause mass chaos. Why?

• Any kind of change in the environment and everything in that environment could be effected. Take the Gulf coast oil spill for instance. Or the spread of lyme’s disease

• Ecology is very difficult to study. Why do you think that?

• One way that we study this is with models. These are used to study environmental interactions and make predictions of what might happen in the future.

• It is not extremely accurate in most cases.

• Levels of organization- There is a natural hierarchy of organisms. Just like a pack of wolves have an alpha male.

• Ex. Each organism is composed of one or more organs, those organs are composed of tissues, tissues are made of cells. That is the same way the environment is.

The Biosphere

• The broadest and most inclusive. • This includes the Earth and its atmosphere. • All organisms are found in this level.• It is approx. 20 km thick (13 miles) • In comparison, think of an apple, The earth

would be the actual apple and the biosphere would be the skin.

Ecosystems

• This includes all living and nonliving organisms in the environment found in a particular place.

• Like a pond- it contains fish, turtles, plants, algae, insects, snakes and bacteria.

• Each of these organisms need the other to survive.

• It also has nonliving components that are needed in the maintenance of life. (pH of the water, levels of oxygen and carbon dioxide)

• Sunlight plays the largest part in a pond ecosystem. Without sunlight not much can live there.

• Communities, populations and organisms- Where an ecosystem involves EVERYTHING a community only includes the LIVING part of the environment.

• Below that is the population- which is the members of one species.

Close- 10 points

• Predicting results- Assuming wolves eat deer, how could a disease that kills a large portion of the wolf population affect the mice population in an area of the eastern United States?

Ecology of Organisms

• Ecosystem components- there are 2 types- biotic and abiotic

• Biotic Factors- living • Abiotic –nonliving(include temp., humidity,

pH, salinity, oxygen concentration, amount of sunlight, precipitation and availability if nitrogen.

• The amount of importance of each factor is depends on each environment.

• These factors are not independent. Organisms change their environment and are influenced by those changes.(nitrogen in the soil)

Organisms in a changing environment

• Each organism is able to survive within a limited range of environmental conditions. Example, Organisms can only survive within a certain temp. range.

• An organism can survive outside that range but its performance is greatly reduced.

Acclimation

• Being able to adjust to the abiotic factors.• Like goldfish, they can live in various temps.• DO NOT CONFUSE- acclimation and

adaptation• Adaptation happens over many generations

and acclimation happens within the its lifetime.

• Some can escape certain conditions by dormancy or migration.

• Dormancy- state of reduced activity.• Migration- move to a different environment.

Niche

• Includes the range of conditions that species can tolerate.

• Some species have more than one niche in their lifetime.

• Like caterpillars, they eat leaves and plants when they are young, but as butterflies they feed on nectar.

Review Questions

• Distinguish b/t biotic and abiotic factors.• What is the difference in a niche and a

habitat?• Why do you think species never occupy the

same niche?

Energy Transfer

• Producers- autotrophic organisms that make their own food.(photosynthesis, chemosynthesis)

• Consumers- have to find food to eat to survive.

Consumers

• Herbivores- plants eaters• Carnivores- meat eaters• Omnivores- both plants and meat• Detritivores- eat the garbage of the ecosystem

Shortcut to Energy Transfer.lnk

Ecosystem Recycling

• The water cycle- water is crucial to life.• Cells contain 70 to 90 percent water.• 3 important processes in the water cycle are

evaporation, transpiration and precipitation.

The carbon cycle

• Photosynthesis and cellular respiration- form the basis of the short term carbon cycle.

Nitrogen Cycle

• The pathway that nitrogen follows in an ecosystem.

Section 4 Review

• What are the 3 geochemical cycles? • Outline the steps of the carbon cycle.• What are decomposers and what are they

used for?• What are the roles of bacteria in the carbon

and nitrogen cycle.