Ecology

Ecology

Ecology…

The scientific study of interactions between organisms and their environment

Levels of Organization

1. Biosphere= thin zone that contains ALL life of Earth

2. Ecosystem= a self supporting group of communities and their

physical environment• Biotic factors: all the LIVING organisms that

inhabit an environment• ‘bio-’ = life • Abiotic factors: all the NONLIVING part of the

environment• ‘a-’ = without; • ‘a’ ‘bio’tic = without life

Draw the table in your notes and put the following under the appropriate heading: rock, flower, sun, popcorn, grass, soil, water, animal, tree, carcass

Living(biotic)

Nonliving(abiotic)

Dead

Living(biotic)

Nonliving(abiotic)

Dead

•Flower•Grass•Animal•Tree

Living(biotic)

Nonliving(abiotic)

Dead

•Flower•Grass•Animal•Tree

•Rock•Sun•Soil•Water

Living(biotic)

Nonliving(abiotic)

Dead

•Flower•Grass•Animal•Tree

•Rock•Sun•Soil•Water

•Popcorn•Carcass

Levels of organization (continued)

3. Community= all the living organisms in a specific area (Ex. Pond, forest)

4. Population:= all the individuals of the same species living in

the same area at the same time5. Organism= any living thing

Overview: (largest smallest)

BiosphereEcosystemCommunity

PopulationOrganism

How to remember order?

Big Elephants Consume Peanuts Often

Habitat= the place an organism lives

Niche= the role (job) an organism has in it’s community

Species= a group of like organisms that can reproduce AND have fertile offspring

NOT a species…

Cat + rabbit = cabbit?Babies are sterile therefore NOT a species

Lion + tiger = ligerBabies are sterile therefore NOT a species

Symbiotic Relationships

Symbiosis= the relationship in which there is a close and permanent association between organisms of different species3 types:

1. Mutualism

Relationship in which both organisms benefitOrganism 1 = = Benefit

Organism 2 = = Benefit

Example of mutualism

Ants and the acacia tree

2. Commensalism

= relationship in which one species benefits and the other is neither harmed nor benefitedOrganism 1 = = benefit

Organism 2 = = no harm, no benefits

Example of commensalism

Spanish moss growing on trees

3. Parasitism

Relationship in which one species benefits and the other is harmedOrganism 1 = = benefit

Organism 2 = = harmed

Example of parasitism

Tapeworms

Overview

Relationship Organism 1 Organism 2

Mutualism Benefit

Benefit

Commensalism Benefit No benefit, not harmed

Parasitism Benefit Harmed

Ecological Niches

1. Producers:Also called autotrophs‘auto-’ = self‘troph’ = feedingThese are organisms that make their own foodEx. green plants

2. Consumers:Also called heterotrophs‘hetero-’ = differentOrganisms that can NOT make their own foodThree categories:A. herbivores: eat plants (primary consumer)

B. carnivores: eat other consumers; eat meat (secondary/tertiary consumers)

C. omnivores: eat both plants and animals (tertiary consumers)

3. Decomposers: break down organic matter and return it to the environment

Food Chains

The flow of energy and organic molecules from organism to organism

Energy for this system originates from the SUNFood chains ALWAYS begin with a PRODUCER

Look at the image to the right and write the correct food chain

Grass insects frog owl hawk

Food WebsComplex relationships formed by interconnecting and overlapping food chains

Practice

Look at the food web diagram providedOn a separate sheet of paper write out ALL the food chains presented within the one food webYou should be able to find TEN!!!

Pyramids

1. Pyramid of numbersThe higher up the food chain the lower the number of organisms (go to handout)

2. Pyramid of energy90% of the energy is lost to the environment at each level of the food chain (go to handout)

3. Pyramid of biomassThe amount of biomass decreases at each level of the food chain (go to handout)

BIOMES

Community DistributionLimiting factor: any biotic or abiotic factor that restricts an organism’s ability to surviveEx. Food supply, water supply, living space

Tolerance: the ability to withstand fluctuations in biotic and abiotic environmental factors

SUCCESSION= the orderly, natural change in communities over timePrimary succession: development of living communities from BARE ROCKNO soil present Ex. Rock lichens moss ferns shrubs trees mature trees

Pioneer organism: the first organism to inhabit a community (ex. lichens)Climax community: a stable, mature community that undergoes little or no succession

Primary succession takes a relatively long time to reach this point

Secondary succession: the development of living communities that takes place when a community is disrupted by natural disasters or human impactSoil IS presentTakes less time to reach climax communityEx. Abandoned farms, fires…

Population Growth

Exponential growth: when the number of organisms increases by an ever-increasing rate.248163264128256etcJ-shaped curve

Carrying capacity: the number of organisms of a population a particular environment can support over an indefinite period of timeS-shaped curve

Factors that affect the size of populations

1. Birth rate2. Death rate3. Growth rate = birth rate – death rate4. Immigration: movement INTO and area5. Emigration: movement OUT of an area