Ecological Relationships

Biosphere  The biosphere is the portion of the earth in which living things and non-living things exist.  The ecosystem is a community and the physical environment that it occupies.

Biotic vs. Abiotic  Biotic factors are living factors  Examples include: animals and plants

Abiotic Factors  Abiotic factors are non- living factors in the environment.  Examples: Water, Oxygen, Light, Sun Temperature, Soil, Rocks

 Biotic factors depend on abiotic factors for there survival. Abiotic factors sometimes become limiting factors. A limiting factor is a factor that controls a process, such as an organism growth or species population, size, or distribution

Producers, Consumers and Decomposers  Energy must flow through an ecosystem to allow organisms to survive and reproduce.  Producers are organisms that are autotrophs. They make up the base of the energy pyramid.  Producers are the most abundant in the ecosystem. –Producers are autotrophs which are organisms that can produce their own food using abiotic factors. (Plants and grass) Examples of autotrophs include organisms that perform what process?

Consumers  Consumers are heterotrophs and must obtain nutrients from other organisms. –There are primary consumers, also known as, first level consumers. –They make up the first level of the energy pyramid. –An example of primary consumers are herbivores. (organisms that eat producers)

Secondary Consumers  Second level on the energy pyramid.  Organisms that make up the second level are considered to be carnivores or meat eaters.  Examples include: frogs, snakes,

Tertiary Consumer  These organisms make up the third level of the energy pyramid.  These organisms are considered to be omnivores, which are organisms that eat meat and plants.  Examples include: grizzly bear, raccoons, skunks, owls

Decomposers  These are the “recyclers” of our food webs and chains. They generate important nutrients for the soil so that producers can grow.  They work by breaking down dead organisms so that the decay can be reused by the ecosystem.  Example of decomposers include: mushrooms, bacteria, mold and worms. worms.  Without decomposers there would be no transfer of energy. Every food chain and web needs decomposers.

The Energy Pyramid  The base of the pyramid is larger and as you move up each trophic level it becomes more narrow.  Why is it bigger on the bottom?  Why does it become more narrow?

 As you move up each trophic level the amount of energy transferred between organisms and the biomass (amount of organisms) decreases.

Food Chains and Webs  Organisms carry out feeding relationships with each other.  When a series of organisms pass energy to and from each other it is called a food chain.  Series of food chains interconnected create food webs.

The arrows in the chain represent the transfer of energy. The direction of the arrow represents where the organism is getting the energy from.

Where is the grasshopper getting it’s energy from? Where is the mouse getting it’s energy from?

Carrying Capacity   Carrying capacity is the amount of organisms that environment can hold.   If carrying capacity is reached no more organisms will reproduce.

Symbiotic Relationships   There are four types of close (symbiotic) relationships that organisms can have.   They include: Predator-Prey, Commensalism, Mutualism and Parasitism.

Predator/Prey   Relationship of the hunter (predator) and the hunted (prey)   Examples include: Predator Prey Hawk Trout Snake Mouse

  Commenselism- A relationship in which one organism benefits and the other is not affected (+,o). – –Examples include: Shark and Remora fish Barnacles and Whales   Mutualism- A relationship where both organisms benefit. (+,+) – –Examples include: Flower and bee Bacteria and legumes

  Parasitism- when one organism benefits and the other is harmed (+, - ). – –The organism that is being harmed is called the host organism. Examples include: Host Parasite Dog Flea Feet Fungus

Materials Cycle   There are certain materials that get recycled in the environment.   The three materials cycle include the carbon-oxygen cycle, the water cycle and the nitrogen cycle.

Carbon-Oxygen   This cycle involves the process of photosynthesis and respiration.   It is the recycling of carbon dioxide, water, oxygen and glucose

The Water Cycle   It is the material cycle the recycles water.   It involves the process of photosynthesis, transpiration, evaporation, condensation and respiration.

The Nitrogen Cycle   Nitrogen cycle recycles the nitrogen necessary for production of proteins.   It involves decomposers and other bacteria that break down nitrogen wastes and the remains of dead organisms.

Ecological Succession   Ecosystems go through changes until a climax (stable) community is attained.   The replacement of one community by another is called ecological succession.   A community can be replaced by another over a long period time.

Primary vs. Secondary Succession   Primary succession begins with pioneer organisms ( bare rock and lichens) and works it way up to a forest or a “climax community”   Secondary succession is when you have a climax community and a natural disaster like a fire destroys and it must rebuild itself again.