ECOLOGY

Ms. Pelullo

2012

The study of interactions among organisms & between organisms and their

environment

LEVELS OF ORGANIZATION

Any one individual living thing

Group of similar organisms that can breed & produce fertile offspring

Group of individuals that belong to the same species & live in the same

areaAssemblage of different populations that live together in a defined area All the organisms that live in a place

together with their physical environment

Group of ecosystems that share similar climates & typical organisms

Entire Planet – All organisms and physical environments

Organism / Species

Population

Community Ecosystem

Biosphere

WHAT’S THE BROADEST LEVEL??

Biosphere Where is it located and what does it include?

Portion of Earth where life exists Consists of all the organismsall the organisms plus their physical

environment Organisms + Land + Water + Atmosphere Extends from about 8km about Earth’s surface to as

far as 11km below the surface of the ocean.

HOW IS ECONOMICS LINKED WITH ECOLOGY?

Humans live within the biosphere and Humans live within the biosphere and DEPEND on ecological processes to provide DEPEND on ecological processes to provide such essentials as food and drinks that can be such essentials as food and drinks that can be bought/sold/traded. bought/sold/traded.

 

  

 

 

 

 

Word Bank 

Biome Population EcosystemCommunity Biosphere Organism

WHICH ECOLOGICAL CATEGORIES IN THE HIERARCHY INCLUDE BOTH BIOTIC AND ABIOTIC FACTORS?

Ecosystem, Biome, Biosphere

WHAT IS THE DIFFERENCE BETWEEN A POPULATION AND A COMMUNITY?

A population is made up of individuals of one species living in the same area, while a community includes a variety of different species in a particular area.

WHAT ARE THE SIMPLESTLEVELS???

Additional: Organelle Tissue

DISTINGUISH BETWEEN FACTORS

Abiotic Biotic

1. Rocks:2. Pine trees:3. Waterfalls:4. Clouds:5. A mushroom in the soil:6. A fish swimming in a lake:

CLASSIFY THE FOLLOWING FACTORS AS BIOTIC, ABIOTIC, OR BOTH:

ENERGY, PRODUCERS, CONSUMERS

As mentioned in our previous unit, materials and energy move between the living (biotic) and nonliving (abiotic) parts of ecosystems.

Materials (atoms, molecules) must be recycled but energy is NOT!

So, a constant supply of energy must enter every ecosystem.

On Earth, what supplies our energy???

Remember, organisms must be able to: a)produce or obtain nutrients

b)convert the nutrients into usable forms of chemical energy (cellular respiration – producing ATP!!)

c)use these forms of energy to power their life processes.

2 CATEGORIES BASED ON HOW LIVING THINGS PRODUCE/OBTAIN NUTRIENTS….

Obtains food by consuming other living things AKA Consumer

Ex: Animals, fungi, bacteria, some microorganisms

Categories:

Herbivores,

Omnivores

Decomposers

Capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds AKA Primary Producer

Ex: All Plants, bacteria, some microorganisms

Heterotrophs Autotrophs

DON’T FORGET – DIFFERENT TYPES OF AUTOTROPHY

WHAT WOULD HAPPEN TO THE AMOUNT OF OXYGEN IN OUR ATMOSPHERE WITHOUT THE PRESENCE OF PHOTOSYNTHETIC PRODUCERS?

The amount of oxygen would decrease to such a low level that we could not breathe.

CONSUMERS:

Primary (first order) - herbivores

Secondary (second order)

Tertiary (third order)

Quatenary (fourth order)

Their feeding strategy can vary depending on what they are eating, and what is eating them!

EXAMPLES OF CONSUMERS

CarnivoresSnakes, cat,

dog, otterScavengers

VultureDecomposers

Bacteria, Fungi

DetritivoresEarthworms,

snails, crabs, shrimp

OmnivoresHumans, bears,

pigs, coati (badger)

HerbivoresCows, deer,

caterpillars

Compare your school to an Ecosystem. Provide levels of organization found within

the school. List Abiotic and Biotic Factors found in and

around the school.

COMPARE YOUR SCHOOL TO AN ECOSYSTEM

Provide levels of organization found within the school.

List Abiotic and Biotic Factors found in and around the school.

Species One Student or One Teacher Population 9th Graders, or All Teaching

Staff Community LHS, Heritage, Collins Ecosystem All the schools + non living

factors – desks, chairs, water, etc.

HOW CAN WE SHOW FEEDING RELATIONSHIPS IN AN ECOSYSTEM???

Food ChainsFood WebsPyramids of EnergyPyramids of BiomassPyramids of Numbers

EN

ER

GY

FLO

W IN

EC

OS

YS

TEM

SFood

Chains

&

Food Webs

Food Chains Energy passing through an

ecosystem in a series of steps. Organisms transfer energy by

eating and being eaten Vary in Length Example – how many steps in the

food chain below?

Food Webs Interconnected food chains Shows networks of feeding

interactions Due to the fact that many animals

eat more than 1 type of food Each step in a food chain/web is

called a trophic level

EN

ER

GY

FLO

W IN

EC

OS

YS

TEM

SFood Chain

s

&

Food Webs

What do you think would happen to the ecosystem above if the algae were killed off?

Since algae are the primary producers in this ecosystem,

providing the energy necessary for life processes in this ecosystem, life in this ecosystem would not continue if algae were killed off

OTHER QUESTIONS TO THINK ABOUT… Food chains and food webs cannot go on

forever; in other words they cannot have an unlimited number of trophic levels. Why do you think this is true?

Some might make an analogy of decomposers being like earth's "recycling center". Summarize the importance of decomposers and detritivores in food webs

Only a small portion of the energy available at each level of the food web or chain is transferred to the

next level (on average, 10 %). Eventually, as we move up the energy pyramid, the amount of energy

transferred will not be enough to support the life processes of another trophic level.

Decomposers break down any dead organisms that have not been consumed into detritus. Detritivores breakdown both decomposers and the detritus that they produce to obtain energy. Without decomposers, nutrients would be locked forever in dead organisms. Instead, these nutrients re-enter the food web through primary producers; they are recycled.

DECOMPOSERS & DETRITIVORES IN FOOD WEBS

Convert dead material into detritus Detritus

Eaten by detritivores Ex: Grass Shrimp, Crayfish, Worms

Decomposition process releases nutrients that can be used by primary producers Nature’s Recyclers Without them – nutrients would remain locked in

dead organisms

HOW DOES ENERGY FLOW THROUGH AN ECOSYSTEM ?In a one-way stream from PRIMARY PRODUCERS to various CONSUMERS

Show relative amounts of energy, biomass, or numbers of organisms in each trophic level of a given food chain or web

ECOLOGICAL PYRAMIDS

PYRAMIDS OF ENERGY

Shows: Relative amount of energy available at each

trophic level of a food chain/food web What happens to the amount of energy

available at each trophic level? DECREASES!!

Only 10% of available energy gets passed up

What is this energy being used for??

PYRAMIDS OF BIOMASS

What’s Biomass??? Total amount of living tissue within a given

trophic level Pyramid of biomass

The amount of biomass a given trophic level can support is determined by the amount of available energy.

Relative amount of living organic matter Greatest biomass is at base – see image

PYRAMIDS OF NUMBERS

Shows the relative number of individual organisms at each trophic level in an ecosystem.

In most ecosystems, the shape of the pyramid of numbers is similar to the shape of the pyramid of biomass for the same ecosystem, with the numbers of individuals on each level decreasing from the level before it.

This is the only pyramid that can be inverted!!

ON YOUR OWN …

Why is a food web a more accurate representation of the feeding relationships in an ecosystem than a food chain?

All of the organisms in one area and their physical environment is known as a(n)

a. Habitat b. Populationc. ecosystem _______ always make up the first trophic level

in a food web. About ___ percent of the energy available

within one trophic level is transferred to the next trophic level.a. 90% b. 10% c. 100% d. 0%

ON YOUR OWN … Why is a food web a more accurate

representation of the feeding relationships in an ecosystem than a food chain? An organism is rarely food for or feeds on just one other

organism; a food web shows the many different feeding relationships that exist between organisms in an ecosystem.

All of the organisms in one area and their physical environment is known as a(n)

a. Habitat b. Population c. ecosystem Primary Producers always make up the first

trophic level in a food web. About ___ percent of the energy available within

one trophic level is transferred to the next trophic level.a. 90% b. 10% c. 100% d. 0%

What is a Niche??Range of physical and biological conditions in which

a species lives, and the way in which a species obtains food/energy to survive and reproduce

Niche describes the following:Where an organism livesWhat it doesHow it interacts with the biotic and abiotic

factors in an environment

Niche refers to an organism’s total way of life!

NICHES AND COMMUNITY INTERACTIONS

Organisms occupy different places in a community because each species has a range of conditions under which it can grow and reproduce

These conditions help define where and how an organism lives

NICHES AND COMMUNITY INTERACTIONS

Every species has its own range of tolerance

What’s Tolerance? the ability to survive and reproduce under

a range of environmental circumstancesExample – temperature, sunlight, rainfallEach organism has an optimum range for best

survival and reproduction

TOLERANCE:

Habitat – general place where an organism lives ; its “address”

HABITAT

Resource –

any necessity of life: water, nutrients, light, food, space

For plants: sunlight, water, soil nutrients For animals: nesting space, shelter, types of

food, places to feed

RESOURCES AND THE NICHE

Physical aspects of the niche: Abiotic factors – sunlight, water, soil, rocks,

temperature

Biological aspects of the niche: Biotic factors – when and how it

reproduces, the food it eats, the way it obtains the food

ASPECTS OF THE NICHE

COMPETITION How does competition shape communities? If you look at any community, you will probably

find more than one kind of organism attempting to use various essential resources.

RELATIONSHIPS

When organisms attempt to use the same limited ecological resource in the same place at the same time, competition occurs.

For example – In a forest – plant roots compete for water and nutrients in the soil.

Competition can occur both among members of the same species (known as intraspecific competition)

and Between members of different species (known

as interspecific competition)