Chapter 3 The Biosphere

Essential Question:

How are ecosystems organized for energy transfer?

THE BIOSPHERESec. 3-1

Ecology is

eco = house

logy = the study of

the study of ecosystems and the

interactions that occur within them

scientists who study ecology are

called ecologists

What are Ecosystems?

Biotic +

Community

Abiotic

Conditions= Ecosystem

Living +

Things

Non-living

Things= Ecosystem

Biotic Factors

Levels of Organization:

- same species in same area

- of a species can interbreed and produce fertile offspring

- all the populations in an area

- living and nonliving

group of similar ecosystems

- Earth +atmosphere

Biotic Communities

Organized into 6

different levels

– Individual

– Population

– Community

– Ecosystem

– Biome

– Biosphere

*KEY POINT* All are connected to one another

Individual

– all the members of

a specific species

– one individual

= one organism

population• all the members of a

single species that

occupy a given area

community • All the different

populations of

plants, animals,

and microbes in a

given area

ecosystem

• Interactions

between the biotic

community and

the non-living

parts of the area

light

species

abiotic

species

soil wind

temperature

moisture

biome

• Similar or related

ecosystems that

are joined

together

• Generally defined by

the prevailing climate

and vegetation

biosphere

• All the biomes

functioning

together in one

giant ecosystem

• The part of the

Earth that living

organisms occupy

What are Ecosystems?

Biotic +

Community

Abiotic

Conditions= Ecosystem

Living +

Things

Non-living

Things= Ecosystem

Abiotic Factorsa = non

biotic = living

all the non-living parts of an ecosystem

that influence the living organisms

Air and Wind

• Chemical Composition

– oxygen, carbon dioxide, nitrogen, other gases

• Physical Movement

– shapes landforms

– creates waves

– stirs up water

Water and Rainfall

• Chemical Composition

– salt, fresh, hard, soft, ph, nitrogen, phosphorus

• Amount of Moisture /

Water

– rainfall:

• amount per year

• distribution around globe

– amount of water in the ground

– vernal (temporary) pool vs. lakes/ponds

Soil, Bedrock and Minerals

• Physical / Chemical Composition

– clay, sandy, cobble, boulders

– calcium, phosphates, etc.

• Amount of Nutrients /

Condition

– rich or poor soil

– ability to retain water

Temperature• extremes of heat

and cold

• average yearly temp

Fire

• helps open new areas

• recycles some minerals

ENERGY FLOWSec. 3-2

Categorizing Living Organisms

Two Major Types of Organisms

– based on how they obtain energy to survive

Autotrophs

auto = self, troph = feeding

Heterotrophs

hetero = other, troph = feeding

Modes of Feeding

Autotrophs = Producers

– make their own food

from raw materials

and an energy source

– do not need other

organisms to survive

Heterotrophs =

Consumers

– cannot make their own

food, must consume

other organisms

– need other organisms

to survive

together they create

•food for all parts of an ecosystem

•pass food along food chains

•return materials to the abiotic parts of the environment

Autotrophs and Heterotrophs

these two types of organisms can be further

divided into different categories based on

the specific ways they make or obtain food

Types of Autotrophs

Photosynthetic

Plants, Protists, Bacteria

Use

chemicals for

energy

basis of ALL

ecosystems

Chemosynthetic

Bacteria

Use sunlight

for energy

Photosynthetic

Plants

Photosynthetic Protists & Bacteria

Chemosynthetic Bacteria

Types of Consumers (Heterotrophs)

Consumers

• Primary (1°)

• Secondary (2°)

• Tertiary (3°)

• Omnivores

• Parasites / Scavengers

• Detritus Feeders / Decomposers

all depend on

Producers

(1°)Primary Consumers

• known as herbivores

• only eat autotrophs

(producers)

(2°) Secondary Consumers

• known as

carnivores

• feed on consumers

ONLY

Omnivore Consumers

• feed on both plants (producers)

and animals (consumers)

(3°) Tertiary Consumers

• feeds on other

carnivores

• sometimes referred to

as higher order

consumers

Specialized Consumers

Parasites

– dependent on other organisms for

food AND shelter

Detritus Feeders

detritus is

–dead plant material

– fecal waste (poop, marine snow)

–dead organisms (animals, insects, etc)

many organisms are specialized to

feed on detritus

Detritus Feeders

• consume detritus

• include–earthworms,

millipedes, crabs, vultures

Decomposers

• cause the rotting

of dead

organisms

• include

–bacteria & fungus

Scavengers

• special type of

consumer that

also acts as a

detritus feeder

Chapter 3.2

Food Webs and Energy

Transfer

How is energy transferred?

What paths does it take?

Food Chains

Kelp Urchins

Sea Otters

Orca

one way flow of energy

Energy Flow / Nutrient Cycling

http://www.ecokids.ca/pub/eco_info/topics/frogs/chain_reaction/index.cfm

Foodwebs

– linked food chains

Producers – first trophic level - make own food

1o Consumers – second trophic level- are herbivores - eat producers

2o Consumers – third trophic level- are carnivores – eat 1o consumers

3o Consumers – fourth trophic level- are carnivores - eat 2o consumers

Food Webs Are Complex!

http://teacher.scholastic.com/activities/explorer/ecosystems/be_an_explorer/map/foodweb_play.htm

Community InteractionsType of

InteractionSymbol Effects

mutualism +/+both species benefit from interaction

commensalism +/0one species benefits, one unaffected

competition -/-each species affected negatively

predation, parasitism, herbivory

+/-one species benefits, one is disadvantaged

Biological Magnification

• Certain chemicals tend

to become more

concentrated as they

travel along the food

chain & can reach toxic

levels

Ex. Ospreys and the

chemical DDT – a

pesticide used to

control malaria.

Caused thinning of

their egg shells –

broke during nesting

= loss of generations

Energy Transfer up Trophic Levels - Each step transfers energy/biomass to another trophic level

Energy is lost as heatduring each transfer

means

less energy/biomassfor organisms in next level

10% rule – only about 10% of the energy availablewithin one trophic level is transferred to organisms at the next trophic level

10% Rule = loss of 90% of energy from the trophic level below

Energy Pyramid:

Shows the relative amount of energy available at each trophic level. Organisms use about 10 % of this energy for life processes. The rest is lost as heat.

Biomass Pyramid:

Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid.

Pyramid of Numbers:

Shows the relative number of individualorganisms at each trophic level.

3-3

CYCLES OF MATTER

Recycling in the Biosphere

• RECALL

– Energy moves in a one-way flow through an ecosystem from organism to organism until it is all lost as heat

– Matter (atoms) are constantly being recycled within and between ecosystems

• Recycling loops in the ecosystem are called biogeochemical cycles

The Water Cycle

• Starts with evaporation or transpiration

• Ends with precipitation

• Important for all living organisms as it provides the environment for almost all the chemical reactions in living things

• Not considered a nutrient cycle by these authors because water is not used to “build” the cells and tissues that make up organisms

The Water Cycle

Evaporation Transpiration

CondensationPrecipitation

Runoff

Seepage

Rootuptake

Nutrient Cycles

• Nutrients are chemicals the body needs to build cellular components and tissues

• The three most important cycles are the carbon cycle, nitrogen cycle and the phosphorus cycle

– Carbon and nitrogen both involve an atmospheric component

– Phosphorus is strictly a geochemical cycle

Limiting Nutrients

• Primary productivity is a measure of the amount of photosynthesis that occurs in any ecosystem

– Since producers are responsible for “fixing” energy in the form of glucose, and other macromolecules, that can be transferred to other trophic levels, any nutrient that would PREVENT this from happening is called a limiting nutrient

• The most common are nitrogen, phosphorus and potassium (the common ingredients in fertilizer)