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

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.