EcologyEcologyThe world around us

EcologyEcology

• the study of the relationships the study of the relationships among living things and their among living things and their interaction with the environmentinteraction with the environment

•Ecosystem (Ecological System): An interacting system of living and non-living components. –A forest, a pond, a stream, a decaying log, an aquarium are all ecosystems. Sometimes called a habitat.

•Biotic and Abiotic factors Biotic and Abiotic factors interact in complex ways interact in complex ways in communities and in communities and ecosystemsecosystems

Biotic factorsBiotic factors• Living factors in an Living factors in an

environmentenvironment

Examples:

Abiotic factorsAbiotic factors• Nonliving factors in an Nonliving factors in an

environmentenvironment

Examples:

Ecosystem Ecosystem InteractionsInteractions

•Habitat- the part of the Habitat- the part of the environment in which an environment in which an organism livesorganism lives–Ex-Ex-

•Niche- the role (job) an Niche- the role (job) an organism hasorganism has–Ex-Ex-

Levels of Levels of OrganizationOrganization

•Population- individuals of a single species that share the same geographic location at the same time

•Community- a group of interacting populations that occupy the same geographic area at the same time

•Ecosystem- a community and all the abiotic factors (nonliving) that affect it

•Biosphere- the part of Earth that supports life

ProducersProducers•photosynthetic photosynthetic organisms (green organisms (green plants).plants).

•Examples:Examples:

I) Autotrophs: organisms that make their own food

II) Heterotrophs: organisms that consume other

organisms

Primary ConsumersPrimary Consumers“Herbivores”“Herbivores”

•Plant eating Plant eating animalsanimals

•Examples:Examples:

Secondary Secondary Consumers Consumers

“Carnivores”“Carnivores”Meat eating animals,Meat eating animals,

may be primary, may be primary, secondary tertiary or secondary tertiary or higher.higher.

Examples:Examples:

Omnivores  Omnivores  

Animals that eat both Animals that eat both plants and animals.plants and animals.

Examples:Examples:

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Scavenger

• Animal that feeds on other animals that are already dead

• Example: vulture

•Break down complex Break down complex nutrients to return them nutrients to return them to the environment for to the environment for reuse. reuse.

•Examples: bacteria, Examples: bacteria, molds, tree bract, molds, tree bract, mushrooms, insect larvamushrooms, insect larva

Decomposers:

Parasites:Parasites:organisms that organisms that take nutrients from, take nutrients from, or use systems of, or use systems of, other living other living organisms. organisms.

Examples: Examples: tapeworm, some tapeworm, some protozoans, leech, protozoans, leech, some fungussome fungus

Pathogens:Pathogens:

Disease causing Disease causing microorganisms. Viruses, microorganisms. Viruses, bacteria, some protists.bacteria, some protists.

Examples: E. Coli, staph, Examples: E. Coli, staph, strept, Flu virus, HIV virusstrept, Flu virus, HIV virus

Community Community InteractionsInteractions

• Competition• Predation• Symbiotic relationships

– Mutualism- organisms benefit from each other

– Commensalism- one organism benefits and the other is neither helped nor harmed

– Parasitism- one organism benefits while the other is harmed

Predator-Prey RelationshipsPredator-Prey Relationships

The Canada Lynx and the Snowshoe Rabbit

- Predator hunts prey

The number of organisms The number of organisms any habitat can support.any habitat can support.

This is limited by the available energy, This is limited by the available energy, water, oxygen, and minerals, and by the water, oxygen, and minerals, and by the ability of ecosystems to recycle the ability of ecosystems to recycle the residue of dead organisms through the residue of dead organisms through the activities of bacteria and fungi.activities of bacteria and fungi.

Carrying Carrying Capacity:Capacity:

Energy in an Energy in an EcosystemEcosystem

•Autotrophs capture Autotrophs capture energy,making it energy,making it available for all available for all members of a food webmembers of a food web

Question: Where do they Question: Where do they capture the energy capture the energy from? from?

Energy Energy FlowFlow

•Autotrophs (make their own Autotrophs (make their own food) food) Heterotrophs (do not Heterotrophs (do not make their own food)make their own food)

•Decomposers- Recycle nutrients from any dead organism

Food ChainFood Chain

Food Food chain- a chain- a series of series of organisms organisms through through which food which food energy is energy is passedpassed

Food webFood web- many food chains connected- many food chains connected

Biomagnification

• Accumulation of substances in larger and larger quantities in bodies of organisms at each higher level of the food chain

• Also known as bioaccumulation

How Biomagnification Works

Biomagnification occurs when contaminants that don’t easily degrade increase with each link of a food chain. In seawater, these persistent molecules stick to small particles and phytoplankton. Small fish eat the phytoplankton, but the contaminants can’t be broken down and are absorbed, intact, by the fish. When small fish are eaten by larger predators, the process repeats—again and again, up the food chain. Each subsequent predator receives a higher dose than the previous one. Animals at the top of the food chain, such as dolphins, receive the most concentrated dose of these contaminants with every meal.

Ecological Ecological PyramidsPyramids

The Energy The Energy PyramidPyramid

Amount of energy available in an ecosystemGreatest amount of energy = producers

Least amount of energy = highest level consumer

Pyramid of biomass- shows relative mass of organisms

Ecological Succession

• The process by which an existing community is slowly replaced by another community

Ecological Succession

• On Land

• In water

• Bog Succession

• Succession on a Glacial Moraine

Pioneer OrganismsThe first organisms to inhabitan area

Examples: In Water: algaeOn Land: lichen

Stable community that develops as a result of succession

Climax Community

Cycles of an Cycles of an EcosystemEcosystem

•Essential nutrients are Essential nutrients are cycled through cycled through biogeochemical processes.biogeochemical processes.

•Water cycleWater cycle•Carbon and Oxygen CyclesCarbon and Oxygen Cycles•Nitrogen CycleNitrogen Cycle•Phosphorous CyclePhosphorous Cycle

The Oxygen/Carbon The Oxygen/Carbon Cycle:Cycle:

       

 

       

 

The Nitrogen CycleThe Nitrogen Cycle Nitrogen is needed for the synthesis Nitrogen is needed for the synthesis of proteins and nucleic acids. Plants of proteins and nucleic acids. Plants can synthesize them from nitrates, can synthesize them from nitrates, animals must eat protein and nucleic animals must eat protein and nucleic acids.acids.