Welcome to the Ecology Tutorial, an Environmental Systems Term Project

This is an introductory page to ecology.Including terminology, ecological components, and links.

Project guidelines 

Ecology is the science that attempts to answer such questions about how the nature works. In 1869, German biologist Ernst Haeckel coined the term ecology from two Greek words: oikos, meaning "house" or "place to live" and logos, meaning study.

Ecology is the study of how organisms interact with one another and with their non-living environment of energy and matter. The key word is interact. Scientist usually carry out this study by examining differentecosystems: communities with groups of different species interacting with one another and their non-living physical and chemical environment.

Ecosystem ComponentsEcosystems consist of various non-living, abiotic, and living, biotic components. The abiotic components of an ecosystem include various physical and chemical factors.The physical factors having the greatest effect on the ecosystem are:

1. sunlight  and shade2. average temperature3. average precipitation and distribution4. wind5. latitude and altitude6. nature of soil (for terrestrial ecosystems)7. fire  (for terrestrial ecosystems)8. water current (for aquatic ecosystems)9. amount of suspended solid material (for aquatic ecosystems)

The chemical factors are:

1. level of water and air in soil2. level of plant nutrients dissolved in soil moisture (for terrestrial) and in the

water (for aquatic)3. level of natural or artifical toxic substances dissolved in soil moisture and in

water4. salinity of water for aquatic ecosystems5. level of dissolved oxygen in aquatic ecosystems

Organisms that make up the biotic component of an ecosystem are usually classified as autotrophs and heterotrophs, based on how they get their food or organic nutrients they need to survive.

Autotrophs(producers)-are organisms that can manufacture the organic compounds they need as nutrients from simple inorganic compounds obtained from their environment. In most terrestrial ecosystems, green plants are the producers. In aquatic ecosystems, most of the producers are phytoplankton, consisting of various species of of floating and drifting bacteria and protist.Most producers make their organic nutrients they need through photosynthesis. The overall net chemical change can be summarized as follows:

6 CO2 + 6 H2O + solar energy -----> C6H12O6 + 6 O2

Some producers , mostly specialized bacteria, can extract inorganic compounds from their environment and convert them into organic nutrient compounds without the presence of sunlight. These producers are calledchemosynthesis. An example of this is around the hydrothermal vents in some parts of the deep ocean. Bacteria carry out chemosynthesis by converting inorganic hydrogen sulfide to organic nutrients.

Heterotrophs(consumers)-are organisms which cannot synthesize the organic nutrients they need and get their organic nutrients by feeding on the tissues of

producers or other consumers. There are several classes of of consumers, depending on there food source.

1. Primary consumers (herbivores) feed directly on plants or other producers.2. Secondary consumers (carnivores) feed only on primary consumers.3. Tertiary or higher level consumers feed only on animal-eating animals.4. Omnivores can eat both plants and animals.Examples are pigs, rats,

cockroaches, and humans.5. Detrtivores (decomposers and detritus feeders) live off of detritus, parts of

dead organisms and castoff fragments and waste of living organisms. Decomposers digest detritus by breaking down the complex organic molecules in these materials into simpler, inorganic compounds. Decomposers consist of various bacteria and fungi.

Types of Species Found in Ecosystems

1. Native species-which normally live and thrive in a particular ecosystem.2. Immigrant species-which migrates into an ecosystem or which are deliberately

or accidently introduced into an ecosystem by humans.3. Indicator species-which serves as a early warning that a community or an

ecosystem is being degraded.4. Keystone species-which plays a role affecting many other organisms in an

ecosystem. The loss of a keystone species can lead to sharp population drops and extinction of other species that depend on it for certain services.

Principal Ways Species Interact

1. Interspecific competition-competition from one or more species for one or more to the limited resources it needs.

2. Predation-an individual organism of one species, know as a predator, feeds on parts or all of a organism of another species, the prey, but does not live in or on the prey.

3. Parasitism-A parasite is a consumer that feeds on another living organism (its host) by living on or in its host organism for all or most of the host's life.

4. Mutualism-is a type of interaction in which both participating species generally benefit.

5. Commensalism-one specie benefits, while the other is neither helped nor harmed to any great degree.

Ecosystem Cycling

Biochemical Cycle-Nutrients, the chemical essential to life, are cycled in the ecosphere and in the mature ecosystems. In these cycles, nutrients move from the environment,through organisms, and back to the environment.

Carbon Cycle-is based on carbon dioxide gas, which makes up only about 0.03% by volume of the troposphere and is also dissolved in water. Carbon is the basic building block of carbohydrates, fats, proteins, nucleic acids, and other organic compounds essential to life.

Nitrogen Cycle-The Earth's largest reservoir of nitrogen is the troposphere, with about 78% of its volume made up of nitrogen gas(N2). Nitrogen is required to synthesize proteins, and nucleic acids. The abundant form of nitrogen cannot be used directly. The conversion of atmospheric nitrogen gas into other chemical forms useful to plants is called nitrogen fixation. This is carried out mostly by certain kinds of bacteria (cyanobacteria) in soil and water and by rhizobium bacteria living swellings, called nodules. Lightning also plays a role in converting nitrogen gas.

Phosphorus Cycle-Various forms of Phosphorous is cycled through water, the earths crust, and living organisms.

Sulfur Cycle-Sulfur enter the atmosphere from natural sources. Hydrogen sulfide, from active volcanoes, and decay of organic matter by anaerobic decomposers.Sulfur dioxide from active volcanoes. Particulate sulfate from sea spray. About one-third of all sulfur compounds and 99% of all sulfur dioxide are sources from human activity.

Hydrologic Cycle (water cycle)-collects, purifies, and distributes the Earth's fixed supply of water. Water is an important medium for the movement of nutrients into and out of ecosystems.

4 Laws of Ecology by Barry Commoner

1. You can't throw anything away2. Can't do just one thing (everything is connected to everything else)3. Nature know best4. No such thing as a free lunch

ELEMENTARY ECOSYSTEMS

Overview:

This lesson teaches students the basics of species interdependency within an ecosystem or habitat. Students will perform a simple simulation to see how one species can affect many others, and gain a basic understanding of the importance of biodiversity. For older students, you may want to define and use the word "ecosystem" in the lesson.

Connections to the Curriculum:Geography, biology, current events, zoology

Connections to the National Geography Standards:Standard 8: "The characteristics and spatial distribution of ecosystems on Earth's surface"

Time:Two to three hours

Materials Required:

Computer with Internet access Photographs of endangered animals (either online or in print) Photographs of human activities that might affect animals' habitats (either online or in print) Drawing materials

Objectives:Students will

describe the things animals need to survive and the ways in which animals depend on other animals and plants;

perform a simulation to demonstrate the interdependencies within an ecosystem; look at pictures of endangered animals, and explain what they think might happen to other

animals and plants if these animals became extinct; and draw pictures of animals in their natural habitats, and describe what these animals need to

survive.

Geographic Skills:

Acquiring Geographic Information Organizing Geographic Information Analyzing Geographic Information

S u g g e s t e d   P r o c e d u r eOpening:Ask students to think of some animals that they are familiar with, such as their pets or animals that live outdoors near their homes. Ask them to state the things these animals need to survive, such as water, food, a place to make their home, and enough room to run and roam.

Development:Ask students to think more carefully about the animals they have described. Discuss the following questions with the class:

What do the animals eat? Where do they live? How do they depend on the plants and other animals around them? What would happen to these animals if their main food source no longer existed?

Assign each student the role of a local plant or animal (more than one student can play the same role). Ask everyone to stand on one side of the classroom. Then ask one "plant" or "animal" to step out of the

picture. For example, you could say, "Will all the oak trees please sit down?" The children taking their seats would represent the dying out oak trees in your area.

Ask students if any other species depend on the oak tree (or whatever local species you have asked to sit down). Give them hints if they are unsure (e.g., the squirrel eats acorns). If any species depends on the species you have asked to sit down, those students will have to sit as well. Continue until there are no (or very few) students left standing.

Discuss the implications of the simulation with the class. What happens to the plants and animals in an area when one type of plant or animal dies out? Make sure students understand that all plants and animals in an area (an ecosystem) depend on one another. Can they think of other examples of dependence, such as in their families, with their friends, or at school?

Have students look at pictures of the endangered animals at thePreserving Biodiversity family activity or at the Bagheera Web site. Explain that there are fewer of these animals in the wild than there used to be. Define the word "extinct" and ask students what they think might happen to other plants and animals if these animals become extinct.

Closing:Have students look at pictures of animals living in their natural habitats. Choose some pictures beforehand, either from books or magazines, National Geographic's Animals guide or Creature Feature archive, or theBagheera Web site. Have students draw pictures of these animals and then describe, either in writing or out loud, the things these animals need to remain healthy and happy.

Suggested Student Assessment:Ask students to brainstorm the reasons why they think some species might be in trouble, in addition to the ecosystem-related reasons they have discussed. Can they think of any ways in which human activities might affect the lives of animals? Show them pictures of construction, recreation, and other human activities, and have them explain how the activities in each picture might affect animals. Ask them to draw pictures of a few of the animals they looked at in the closing, and draw them in their natural habitats. Then have them draw examples of how human activities might cause problems for the animals.

Extending the Lesson:Have students draw pictures of healthy ecosystems in which many plant and animal species coexist. They can get ideas from pictures of natural areas near their homes or other print or Web materials you have available. Ask them to describe, either in writing or out loud, what would happen if the trees or another species were to die off.

Related Links:

Bagheera: A Web Site for Endangered SpeciesNational Geographic: Animals GuideNational Geographic: Creature FeatureNational Geographic: Geography Action! 2003HabitatsWorld Wildlife Fund