ECOLOGYECOLOGY

What is What is EcologyEcology??

Study of interactions between Study of interactions between organismsorganisms and their environmentand their environment..

Ernst Haeckel – coined term Ecology in 1866

Greek word “oikos” means house

Why does this make sense?

Three Ecological Methods of StudyThree Ecological Methods of Study

1.1. ObservingObserving• What species live here?What species live here?

• How many individuals of species are there?How many individuals of species are there? 2.2. Experimenting Experimenting

• Used to test a hypothesis Used to test a hypothesis • Ex - making artificial environments in the labEx - making artificial environments in the lab

3.3. Modeling Modeling • Making models to gain insight into complex Making models to gain insight into complex

phenomena phenomena • Ex. - Global warmingEx. - Global warming

BiosphereBiosphere

The part of the earth where life exists including The part of the earth where life exists including land, water, air, and atmosphereland, water, air, and atmosphere

Living vs. Nonliving Parts Living vs. Nonliving Parts of the Environmentof the Environment

BIOTICBIOTIC – This term describes the living – This term describes the living parts of the environment (animals, plants, parts of the environment (animals, plants, fungi, bacteria, protists, etc.)fungi, bacteria, protists, etc.)

ABIOTICABIOTIC – This term describes the – This term describes the nonliving parts of the environment (air, nonliving parts of the environment (air, water, rocks, soil, light, etc.)water, rocks, soil, light, etc.)

Levels of OrganizationLevels of Organization Ecologists study Ecologists study

several different levels several different levels of organization:of organization: SpeciesSpecies PopulationPopulation CommunityCommunity EcosystemEcosystem BiomeBiome BiosphereBiosphere

SpeciesSpecies

Group of similar Group of similar organisms that can breed organisms that can breed and produce fertile and produce fertile offspringoffspring

group of organisms, all of the same species, group of organisms, all of the same species, which interbreed and live in the same area.which interbreed and live in the same area.

PopulationPopulation

A population of bullfrogs in a pond

CommunityCommunity an assemblage of different populations that live an assemblage of different populations that live

togethertogether

EcosystemEcosystem

Community of organisms (biotic) that live in a Community of organisms (biotic) that live in a place with the nonliving environment (abiotic)place with the nonliving environment (abiotic)

BiomeBiome Group of ecosystems with the same climate and Group of ecosystems with the same climate and

dominant commutiesdominant commuties

Tropical rain forest

Tropical dry forest

Tropical savanna Temperate woodlandand shrubland

Desert

Temperate grassland

Boreal forest(Taiga)

Northwesternconiferous forest

Temperate forest

Mountains andice caps

Tundra

Habitat and NicheHabitat and Niche

HabitatHabitat – where an animal lives out its life – where an animal lives out its life

NicheNiche – the role or position a species has in – the role or position a species has in its environment. Kind of like its JOB!its environment. Kind of like its JOB!

A species usually occupies a niche different A species usually occupies a niche different from those of other species.from those of other species.

What is a polar bear’s habitat? Its niche?What is a polar bear’s habitat? Its niche?

Autotrophs vs. HeterotrophsAutotrophs vs. Heterotrophs

AutotrophsAutotrophs – make – make their own foodtheir own food so so they are called they are called PRODUCERSPRODUCERS

HeterotrophsHeterotrophs – get – get their food from their food from another source so another source so they are called they are called CONSUMERSCONSUMERS

Two Main forms of Energy for Two Main forms of Energy for AutotrophsAutotrophs

SunlightSunlight The main source of The main source of

energy for life on earthenergy for life on earth PhotosynthesisPhotosynthesis

Chemical Chemical Some organisms such as Some organisms such as

bacteria, rely on the bacteria, rely on the energy stored in energy stored in inorganic compoundsinorganic compounds

ChemosynthesisChemosynthesis

Types of ConsumersTypes of ConsumersHerbivores- only eat plants Carnivores - only eat animals

Omnivores- eat plants AND animals

Detritivores and Decomposers

Feeds on plant and animal remains

How does How does EnergyEnergy flow flow through an Ecosystem?through an Ecosystem?

Energy flows Energy flows through an through an ecosystem in ONE ecosystem in ONE directiondirection sunsun or or chemicalschemicals

autotrophsautotrophs

heterotrophsheterotrophs

Energy Flow in Ecosystems:Energy Flow in Ecosystems:

Feeding RelationshipsFeeding Relationships Food ChainFood Chain – steps of – steps of

organisms transferring organisms transferring energy by eating & being energy by eating & being eateneaten

Food WebFood Web – network – network of all the food chains in of all the food chains in an ecosysteman ecosystem

Food Web Food Web (notice the direction of the arrows!!)(notice the direction of the arrows!!)

Ecological Pyramids Ecological Pyramids

Energy Pyramid

Biomass Pyramid

Pyramid of Numbers

Trophic LevelTrophic Level – – each stepeach step in a food chain or food in a food chain or food webweb

Pyramid of Numbers -Pyramid of Numbers -relative relative number of individualsnumber of individuals at each trophic level at each trophic level

Pyramid of Biomass - Pyramid of Biomass - amount of amount of potential food availablepotential food available for each trophic level for each trophic level

Pyramid of Energy – Pyramid of Energy – amount of energy available at each trophic levelamount of energy available at each trophic level

Most of the Most of the energy is used energy is used by the by the organisms for organisms for life processeslife processes

Some of the Some of the energy is lost energy is lost as heatas heat

Only 10% of the energy from each trophic level is passed on to the next levelOnly 10% of the energy from each trophic level is passed on to the next level

100%

100%

10%

1%

0.1%

How doesHow does MatterMatter move move through an ecosystem?through an ecosystem?

Unlike the one way flow of energy, matter is recycled within & between ecosystems

Nutrients are passed between organisms & the environment through

biogeochemical cycles

Biogeochemical Cycles: Bio –life Geo – Earth Chemo – chemical

1. WATER CYCLE

2. NUTRIENT CYCLES:a) CARBON CYCLEb) NITROGEN CYCLEc) PHOSPHORUS

CYCLE

Why are nutrients Why are nutrients important ?important ?

95% of your body is made of…1) OXYGEN

2) CARBON

3) HYDROGEN

4) NITROGEN

Every living organism needs nutrients to build tissues and carry out essential life functions.

Availibility of nutrientsAvailibility of nutrients If a nutrient is in short

supply, it will limit an organisms growth. It is called a limiting nutrient.

When a nutrient is dumped into a lake or pond, an algal bloom occurs and can disrupt the ecosystem!

THE WATER CYCLETHE WATER CYCLE

CARBON CYCLE (see fig.3-13)CARBON CYCLE (see fig.3-13)

4 PROCESSES MOVE CARBON THROUGH ITS CYCLE:

1) Biological

2) Geochemical

3) Mixed biochemical

4) Human Activity

CO2

CO2

NITROGEN CYCLE (see fig.3-14)NITROGEN CYCLE (see fig.3-14)

Nitrogen-containing nutrients in the biosphere include:

1) Ammonia (NH3)

2) Nitrate (NO3-)

3) Nitrite (NO2-)

ORGANISMS NEED NITROGEN TO MAKE

AMINO ACIDS FOR BUILDING PROTEINS!!!

N2 in Atmosphere

NH3

N03- &

N02-

Nitrogen fixationNitrogen fixation – turning unusable – turning unusable nitrogen gas (N2) into useable nitrate, nitrite, nitrogen gas (N2) into useable nitrate, nitrite, or ammoniaor ammonia

How does it happen? Lightning (atmospheric How does it happen? Lightning (atmospheric nitrogen fixation) or Bacteria (bacterial nitrogen fixation) or Bacteria (bacterial nitrogen fixation)nitrogen fixation)

DenitrificationDenitrification – the reverse process. – the reverse process. Turning useable nitrate, nitrite, or ammonia Turning useable nitrate, nitrite, or ammonia back into nitrogen gas!back into nitrogen gas!

PHOSPHORUS CYCLE (See fig.3-PHOSPHORUS CYCLE (See fig.3-15)15)

PHOSPHORUS FORMS PART OF IMPORTANT LIFE-SUSTAINING MOLECULES (ex. DNA & RNA)