Ecology – Organisms & Their Environment Dr. Childs Science Computer Lab Spring, 2005

Ecology Ecology is the interaction of living organisms and their environment This lesson will emphasize: Relationships between organisms Food webs

Biotic & Abiotic Factors Biotic Factors - Living organisms Abiotic Factors– Nonliving

Biotic Factors Plants & Animals

Abiotic Factors Soil Sunlight Water Climate Rocks Air

Aquatic Ecosystem Population Community Ecosystem Terrestrial Ecosystem Organism Relationships Marine Ecosystem

Organism - A single living individual

Population - -A group of organisms of the same species - -Live in same area - - Interact & interbreed

Community - -Populations of different species of plants and animals that live together and interact with each other

Ecosystem - -A community with biotic and abiotic factors. - -terrestrial land - -aquatic fresh water - -marine salt water

Ecosystem

Terrestrial Ecosystem - -Terrestrial ecosystem - -Examples: - - forest - desert - - field - jungle - - large dead tree

Aquatic Ecosystem - -Aquatic ecosystem - -Examples: - - lake - stream - - river

Marine Ecosystem - -Marine ecosystem - -Examples: - - ocean - estuary - tidepools

Community Interrelationships - -Symbiosis: - -Mutualism - -Commensalism - -Parasitism - -Predation

Mutualism - -Both organisms benefit Clownfish & anemone Insects and flowers Lichen – algae & fungi Termite protozoa – digests cellulose

Commensalism - -One organism benefits, other not harmed Remora fish on turtle Barnacles on mussel Cattle egrets with cows Spanish moss on oak

Parasitism - -One organism benefits, other harmed, but not killed Tapeworm in intestine Ticks on dog Fungus on human Malaria in human blood

Predation - -One organism benefits (predator), other is killed (prey)

Food Chains Food chains show how animals get their food. They also show how energy is gained and lost in an ecosystem.

Autotrophs Produce own carbon compounds (sugars) Energy from sunlight - photosynthesis Includes algae and plants

Heterotrophs Carbon compounds from other organisms Fungi (include decomposers) Protozoa and animals

Herbivores Herbivores are animals that eat only plants Flat grinding molars

Carnivores Carnivores are animals that eat other animals - - Meat-eaters

Carnivores Pointed canines for grasping and tearing

Omnivores Omnivores are animals that eat both plants and animals

Omnivores Both sharp canines & grinding molars

And our favorite Pizza-vores

Food Chains Sunlight Producer Secondary consumer Primary consumer Scavenger Decomposer

Sunlight Sunlight is the source of energy in an ecosystem.

Producers Producers: - are green plants - capture energy from the sun - convert to sugars by photosynthesis - fix CO 2 into sugars - release oxygen (O 2 ) - are autotrophs

Producers Algae Microscopic plankton

Primary Consumers / Herbivores Primary consumers eat producers / plants - herbivores - heterotrophs - among the smallest and largest creatures

Primary Consumers / Herbivores

Secondary Consumers Secondary consumers eat primary consumers.

Secondary Consumers

Scavengers Scavengers: - Eat dead and rotting meat Vulture Hyena

Decomposers Decomposers: Digest and break down dead bodies into simple molecules. Recycle nutrients. - Includes: fungi insects bacteria worms

Decomposers

Food Webs - -The interactions among animals for food is never as simple as food chains. For example, bears may eat plants or small animal. Eagles may eat fish or small mammals. - -These interactions are called a “food web”.

Food Webs - Terrestrial

Food Webs - Marine

Trophic Levels - - Levels is a food chain may be defined in terms as energy as “trophic levels”. - -Energy is lost through each trophic level. This energy is used to maintain the organism or even lost as heat.

Trophic Levels - -Organisms are the same trophic level get their energy from the same sources. - -There are rarely more than 4 or 5 trophic levels because of the amount of energy lost.

Trophic Levels Sunlight 1 st trophic Level 2nd trophic Level 3 rd trophic Level 4th trophic Level Note: grasshopper and rabbit are at the same trophic level

Energy Pyramids Energy pyramids represent the amount of total energy in a trophic level. May be represented as “calories” or “joules” Producers are at the bottom and each trophic level in on top.

Energy Pyramids - -The size of each level represents the biomass – the sum of the mass of all the organisms at that level. - -Be aware that sometimes the producer levels are smaller than the consumers because the producer may reproduce much faster. - - There may be only about 10% of energy from one level to the next.

Energy Pyramid