Chapter 4: Ecosystems, Chapter 4: Ecosystems, Ecology, and Food WebsEcology, and Food Webs

Doug Friedman, Jane Beiner, Shayna Benavidez

Article I: Ecology & LifeArticle I: Ecology & Life

EcologyEcology

Ecology in Greek is “house or place to live”Study between organisms & their

environmentExamining how organisms interact with

their environment

OrganismsOrganisms

Forms of Life which can be classified into species

5-100 million species, most are insects and microorganisms

About 1.8 million named

Wild & Domesticated SpeciesWild & Domesticated Species

Wild A species that lives in

its natural environment (where it’s ancestors lived)

Domestic A species that was

removed from its natural environment and placed in an environment that supports the needs and wants of HUMANS

Some Words to KnowSome Words to Know

Populations– Organisms that are part

of the same species and live in the same area of space

Genetic Diversity– Each different

organism has a different genetic make-up

Habitat– The place where a

population lives. Each one can very in size and place.

Biological Community– A population that

consists of a variety of species that live in a particular place.

One more WordOne more Word

Ecosystem– A community of different species interacting

with other species & their non-living environment

Natural or Artificial

LIFE!LIFE!

Living things are made up of one or more calls containing DNA

DNA is the instructions for making new cells and amino acids

Metabolism– Chemical reaction that capture and transform

matter and energy from the environment to supply the organism

More LIFEMore LIFE

Homeostasis– Maintains optimal conditions despite changes

to the environmentReproduction

– Asexual Single cell division, or self fertilization

– Sexual Organisms exchange gametes and fertilize the ova

to create offspring.

Article II: Earth’s Life-Support Article II: Earth’s Life-Support SystemsSystems

LayersLayers

Core– Fe and Trace N– Solid & Liquid

Mantle– Fe, Si, O, Mg– Solid and Liquid

Responsible for continental drift

Crust– Fossil Fuels– Where we life

SpheresSpheres

Lithosphere– Upper mantle and crust

Atmosphere– Thin envelope of air around the lithosphere

Bio-Ecosphere– Biotic and Abiotic Habitats

What is Needed to Sustain What is Needed to Sustain Life?Life?

One way flow of energy– EX: Sunlight through feeding cycles, then into

environment and eventually back out as infrared rays

Cycle of Matter and NutrientsGravity

CyclesCycles

Carbon– CO2 from the atmosphere and earth’s water.

PHOTOSYNTHESIS

Phosphorus– DNA transfers

Nitrogen– Atmospheric N to the soil, helps with amino acids

Water– Storage, evaporation, precipitation, runoff

Oxygen

Open or Closed?Open or Closed?

Closed– ENERGY is exchanged with the environment

(earth)

Open– ENERGY and MATTER is exchanged with the

environment (animals)

The SunThe Sun

PhotosynthesisCO2 + H2O + sunlight C6H12O6 + O2

Earth gets 1 billionth of the sun’s energy28% is reflected into space.023% gets absorbed by plants

Article III: Ecosystem Article III: Ecosystem ConceptsConcepts

IntroIntro

Biomes– Large Regions Characterized by features

Basic Zones– Land– Ecotone (transition)– Aquatic

Components of an EcosystemComponents of an Ecosystem

“tics”– Biotic

Living part of ecosystem

– Abiotic Non-living part of ecosystem

ABIOTICABIOTICExamples

• Air• Water• Nutrients• Solar Energy• Precipitation• Wind• Altitude• Latitude• Frequency of Fire• Nature of Soil• Water Currents• Concentrations

Laws and FactorsLaws and Factors

Law of Tolerance– The existence, abundance,

and distribution of a species in an ecosystem are determined by whether the levels of one or more physical or chemical factors fall within the range tolerated by that species

Limiting Factor Principle– Too much or too little

of any abiotic factor can prevent growth of a species

BIOTICBIOTIC

Autotrophs-Producers– Photosynthesis– Chemosysthesis

Heterotrophs-Consumers– Herbivores-Primary– Carnivores-Secondary-Tertiary– Scavengers

eat already dead animals

ContinuedContinued

Decomposers– Break down dead organisms into nutrients– Detritivors

eat dead animals

– Bacteria– Fungi

GOAL OF ALL PRODUCERS GOAL OF ALL PRODUCERS & CONSUMERS& CONSUMERS

Aerobic RespirationC6H12O6 + O2 CO2 + H2O +ENERGYENERGY

Article IV: Food Webs and Article IV: Food Webs and Energy Flow in EcosystemsEnergy Flow in Ecosystems

A few DefinitionsA few Definitions

Trophic Level– Feeding level

Biomass– Dry weight which is not counted with water

because water is not a source of energy– Only small amounts of what is eaten is actually

converted into biomass

ENERGYENERGY

Some energy is lost from trophic level to trophic level

5-20% of energy is transferred from level to level The more trophic levels the greater cumulative

loss of flow (pyramid of energy flow)– The energy flow triangle shows earth could support

more people if we ate grains instead of grazing animals

ENERGY (ct’d)ENERGY (ct’d)

There energy loss is so large we can only support 4-5 trophic levels

Gross Primary Productivity (GPP):– The rate it takes ecosystems to convert solar energy

into chemical energy as biomass

Net Primary Productivity (NPP):– It is what is left of the biomass after the organism has

used parts of it to stay alive, and reproduce

ENERGY (ct’d)ENERGY (ct’d)

NPP is available to other organisms as food The earth’s total NPP is the upper limit

determining the planets carrying capacity for all species

Most Productivity:– Estuaries– Swamps– Marshes– Tropical Rain Forest

ENERGY (ct’d)ENERGY (ct’d)

Least Productive:– Open Ocean– Tundra– Desert

59% of NPP from Land, 41% of NPP from Water Open ocean contributes a lot to NPP but

phytoplankton is not reasonably harvestable HUMANS waste 27% of potential NPP and 40%

of actual

TATS ALLTATS ALL