ECOLOGY• the scientific study of interactions

among organisms and their environment

BIOSPHERE

BiomesLatitude and Elevation Determine Abiotic Factors

Abiotic Factors Determine Biotic Factors

Ecoregions

Levels of OrganizationLevel Example

EcosystemAll of the biotic (living) and abiotic (non-living) factors that interact in an area make up the ecosystem.

All of the populations (the community) and the saltwater, the temperature, the rocks and minerals, the atmosphere…

CommunityAll of the different populations that interact with each other

A flock of seagulls, a school of redfish, a school of mullet, a pod of dolphins, a flock of pelicans, etc…

PopulationA group of individuals of same species that interact with each other

A FLOCK of seagulls

OrganismAn individual member of a species

A SEAGULL

What is an ecosystem?• a community of living organisms and

the nonliving components of their environment, interacting as a system

• The biotic and abiotic components are linked together through nutrient cycles and energy flowsBIOTIC = LIVING FACTORS

ABIOTIC = NONLIVING FACTORS (NEVER WERE ALIVE)

Biotic factors are affected by abiotic factors…and vice versa

ABIOTIC FACTORS BIOTIC FACTORS

Sunlight Primary producers

Temperature Herbivores

Precipitation Carnivores

Water or moisture Omnivores

Soil or water chemistry Detritivores

All of these vary over space/time

The “Chain of Command” in ecosystems

Abiotic factorsdetermine the type of...

Producerswhich determine the type of…

Consumersthat can live in an ecosystem.

List at least 3 biotic and 3 abiotic factors in this ecosystem

How does ENERGY flow through an ecosystem?

• We use models to show how energy flows in an ecosystem– Food chain

– Food Web

– Energy Pyramid

Food Chain vs. Food Web• Shows one path of

energy.• Almost always

start with a plant transforming energy from the sun.

• If the chain is broken, all organisms beyond that point are wiped out.

• Shows multiple paths of energy.

• Also start with plants.

• If the links are broken, the rest of the organisms get their energy from somewhere else.

The arrow points in the direction that the energy flows!

Food Webexample

If the mice die, I get more energy from other resources!

The Energy Flow PyramidEnergy in an ecosystem begins with the sun’s radiant

energy…Then plants use it to make GLUCOSE as chemical

energy…Then herbivores eat plants and digest the glucose for

energy… Then carnivores eat herbivores… and so on.

Trophic levels

How does MATTER get recycled in an ecosystem?

NUTRIENT CYCLES

Nitrogen Cycle

Carbon Cycle

Phosphorus Cycle

ABIOTIC CYCLES

Water cycle

Rock cycle

Processes that cycle nutrients between abiotic and biotic

• Decomposition- bacteria and fungi break down dead organisms and return nutrients to the environment

• Photosynthesis and respiration- cycle oxygen, carbon dioxide and water vapor

• Precipitation- cycling of water between environment and living things

Biodiversity & Sustainability

-Biodiversity is the variety of life forms- plant, animal, fungi, microorganisms- in an ecosystem.-Greater biodiversity = stronger ecosystem.

-Sustainability is the strength of an ecosystem to be able to support biodiversity.-Sustainability depends on amount of resources such as clean water, nutrients, space, etc.

Ability +

Sustain=

Sustainability

Measuring Biodiversity• Number of different species• Number of different organisms• Biomass –the mass of all the living

things

What is Succession?

• Over time, an ecosystem can change as species are added or replaced.

• Species tend to get larger and more complex

• The biodiversity also increases as an ecosystem changes.

• This change is called succession

SuccessionPrimary Succession--Major catastrophic event-“Starting from scratch”-Very slowBare rock or poor soilLichens, tiny plantsFlowers, grassesShrubs and bushesSmall treesLarger trees

Secondary succession

-Minor catastrophic event

-“Re-growth” (After fire)-Seeds and soil left

behind = faster

How does succession “start”?

• A bare ecosystem has rock and lichens to create soil…

• Other abiotic factors include natural resources such as water, space, light, and nutrients created by decomposers…

• This makes a niche available that invites PIONEER SPECIES to develop in that ecosystem…

PIONEERS

Stages of Succession• Primary

rocks & lichensgrasses

• Intermediatesmall treesshrubs

• Climaxmature trees

Primary Succession

Secondary Succession

When does succession “stop”?

• When the ecosystem has developed as much as it can based on the abiotic factors available…

• These abiotic factors include natural resources such as water, space, light, and nutrients…• When succession “STOPS” this is

called EQUILIBRIUM.

Check your understanding:1. In every ecosystem, energy is ____ and matter gets

_____.2. Changes in an ecosystem are called ___.3. Succession happens in every ___.4. _____and erosion break down rock into sediments.5. Nutrients in the soil come from ___ breaking down

dead materials.6. The three main stages of succession are ___, ___,

and ___.7. The types of producers in an ecosystem depend on

the ___.8. The types of consumers in an ecosystem depend on

the ___.9. The first species to live in an ecosystem are called

___ species.10. When succession stops, it has reached ___.