ecology – organisms & their environment dr. childs science computer lab spring, 2005

Ecology –Ecology –Organisms & Their Organisms & Their EnvironmentEnvironment

Dr. Childs

Science Computer Lab

Spring, 2005

EcologyEcology

Ecology is the interaction of living organisms and their environment

This lesson will emphasize:• Relationships between organisms• Food webs

Biotic & Abiotic FactorsBiotic & Abiotic Factors

Biotic Factors - Living organisms

Abiotic Factors–Nonliving

Biotic FactorsBiotic Factors

Plants & Animals

Abiotic FactorsAbiotic Factors

Soil

Sunlight

Water

Climate

Rocks Air

Aquatic Ecosystem

Population

Community

EcosystemTerrestrial Ecosystem

Organism

RelationshipsRelationships

Marine Ecosystem

OrganismOrganism- A single living individual

PopulatioPopulationn

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

CommuniCommunityty

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

EcosysteEcosystemm

- A community with biotic and abiotic factors.

- terrestrial land- aquatic fresh water- marine salt water

EcosystemEcosystem

Terrestrial Terrestrial EcosystemEcosystem

- Terrestrial ecosystem

- Examples:- forest- desert- field- jungle- large dead tree

Aquatic EcosystemAquatic Ecosystem

- Aquatic ecosystem

- Examples:- lake- stream- river

Marine EcosystemMarine Ecosystem

- Marine ecosystem

- Examples:- ocean- estuary- tidepools

Community Community InterrelationshipsInterrelationships- Symbiosis:

-Mutualism-Commensalism-Parasitism

- Predation

MutualismMutualism

- Both organisms benefit

Clownfish & anemone

Insects and flowers

Lichen – algae & fungi

Termite protozoa – digests cellulose

CommensalismCommensalism

- One organism benefits, other not harmed

Remora fish on turtle

Barnacles on mussel

Cattle egrets with cowsSpanish moss on oak

ParasitismParasitism

- One organism benefits, other harmed, but not killed

Tapeworm in intestine

Ticks on dog

Fungus on human

Malaria in human blood

PredationPredation

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

Food ChainsFood 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 organismsFungi (include decomposers)Protozoa and animals

HerbivoresHerbivores

Herbivores are animals that eat only plants

Flat grinding molars

CarnivoresCarnivores

Carnivores are animals that eat other animals- Meat-eaters

CarnivoresCarnivores

Pointed canines for grasping and tearing

OmnivoresOmnivores

Omnivores are animals that eat both plants and animals

OmnivoresOmnivores

Both sharp canines & grinding molars

And our favoriteAnd our favorite

Pizza-vores

Food ChainsFood Chains

Sunlight

Producer

Secondary consumer

Primary consumer

Scavenger

Decomposer

SunlightSunlight

Sunlight is the source of energy in an ecosystem.

ProducersProducers

Producers:

- are green plants- capture energy from the sun- convert to sugars by photosynthesis- fix CO2 into sugars- release oxygen (O2)- are autotrophs

ProducersProducers

Algae

Microscopic plankton

Primary Consumers / Primary Consumers / HerbivoresHerbivores

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

Primary Consumers / Primary Consumers / HerbivoresHerbivores

Secondary Consumers

Secondary consumers eat primary consumers.

Secondary Consumers

ScavengersScavengers

Scavengers:- Eat dead and rotting meat

Vulture Hyena

DecomposersDecomposers

Decomposers:

Digest and break down dead bodies into simple molecules. Recycle nutrients.

- Includes: fungiinsects bacteriaworms

Decomposers

Food WebsFood 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 - TerrestrialFood Webs - Terrestrial

Food Webs - MarineFood Webs - Marine

Trophic LevelsTrophic 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 LevelsTrophic 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 LevelsTrophic Levels

Sunlight

1st trophic Level

2nd trophic Level

3rd trophic Level

4th trophic Level

Note: grasshopper and rabbit are at the same trophic level

Energy PyramidsEnergy 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 PyramidsEnergy 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 PyramidEnergy Pyramid

Energy PyramidEnergy Pyramid

Energy Energy PyramidPyramid