Are You Smarter Than A 5th Grader?
Acorn barnacles are seashore animals found on rocks.
They live 1 to 2 meters above low-tide level. These rocks are the
acorn barnacles’ —
A) ecosystem
D
B) community
C) food web
D) habitat
Ecology
What is Ecology?
Ecology: the scientific study of interactions among and
between organisms (biotic factors) and their
environment (abiotic factors)
- the environment can be a single cell or an entire planet
Biosphere: contains the combined
portions of the planet in which
all life exists (land, water, air)
extends about 8km above
the surface of earth and
11 km below the surface
Interactions with in the biosphere produce
a web of interdependence between
organisms and the environment
….interdependence contributes to a
dynamic biosphere
To understand relationships within the
biosphere, ecologists ask questions about
events and organisms that range in complexity
from a single individual to the entire
biosphere
Levels of Organization
- species: group of individuals so similar that
they can breed and produce fertile offspring
- populations: groups of individuals that
belong to the same species and live in the
same area.
- communities: different populations that live
together in the same area
- ecosystem: a collection of all the organisms
that live in a particular place, together with
their nonliving environment
- biome: a group of ecosystems that have the
same climate and communities
A little about elk in the Great Smoky Mountains
http://www.nps.gov/grsm/photosmultimedia/video-elk.htm
With your small group, discuss how the reintroduction of
elk to Virginia could impact the deer population?
Ecological Methods
Ecologists use several tools and techniques to
study the living world
Regardless of the tools they use, scientists
conduct modern ecological research using
three basic approaches:
observing, experimenting, and modeling.
Binoculars, field guides, DNA, radio tags, capture
and release, satellites
- Observing: often the first step in asking
ecological questions
what species lives here?
- Experimenting: experiments can be used to
test hypothesis
artificial environment in lab so conditions
can be manipulated or in natural ecosystem
- Modeling: ecologists make models to gain
insight into complex ideas such as the effects
of global warming on ecosystems (usually
cover long periods of time)
consist of mathematical formulas from
data collected
Ecological Methods
Observation
Experiment
Experimental plots,
field sites, laboratory
Tapes, compass,
Measuring Tools Tapes, compass,
Global Positioning
Global Positioning
System, thermometer, System, thermometer,
sensors
sensors
Magnifying Tools Binoculars, microscope, Binoculars, microscope,
telescope
telescope
Sites
Written Record
Field site
Model Building
Many sites for data
collecting
Aerial views, Global
Positioning System,
weather balloons
Satellite images
Notes, automated data Notes, automated data Automated data storage
storage
storage
Chemical Testing Test kits
Test kits
Computer/
Calculators
Mathematical analysis Mathematical analysis
and graphics, statistics and graphics, statistics,
simulations
Mathematical analysis
and graphics, statistics
Large database,
multiple sensors
Section Quiz
The combined portions of the planet in which life
exists, including land, water, and the
atmosphere, form the
biosphere.
community.
species.
ecosystem.
Section Quiz
The combined portions of the planet in which life
exists, including land, water, and the
atmosphere, form the
biosphere.
community.
species.
ecosystem.
Section Quiz
A group of organisms that can breed and produce
fertile offspring is known as a(an)
ecosystem.
species.
biome.
community.
Section Quiz
A group of organisms that can breed and produce
fertile offspring is known as a(an)
ecosystem.
species.
biome.
community.
Section Quiz
Compared to a community, an ecosystem
includes
the nonliving, physical environment as well as the
community.
only the physical environment of an area without the
organisms.
the entire biome but not the biosphere.
only one of the populations within the community.
Section Quiz
Compared to a community, an ecosystem
includes
the nonliving, physical environment as well as the
community.
only the physical environment of an area without the
organisms.
the entire biome but not the biosphere.
only one of the populations within the community.
Energy Flow
The flow of energy through the ecosystem is one
of the most important factors that determines
the capacity to sustain life.
- without energy, living systems cannot
function
Sunlight is the main energy source
for life on earth
A few organisms obtain energy from a source
other than sunlight
Some types of organisms rely on the energy
stored in inorganic chemical compounds -- water from hot springs
- deep ocean vents
Autotrophs: organisms that can capture energy
from sunlight or chemicals to produce food
- plants, some algae, some bacteria
- called producers because they make their
own food
Autotrophs are essential to the flow of energy
through the biosphere.
Autotrophs use photosynthesis to convert
water and carbon dioxide into food while
giving off oxygen
When organisms use chemical energy to
produce carbohydrates, the process is
called chemosynthesis
plants
bacteria
Bacteria perform
chemosynthesis—
symbiotic
relationship with
tubeworms
Organisms that rely on other organisms for their
energy and food supply are called
heterotrophs
- also called consumers
There are many different types of heterotrophs:
herbivores, carnivores, omnivores, and
detritivores
Herbivores: obtain energy by eating only plants
cows, caterpillars, deer
Carnivores: obtain energy by eating animals
snakes, dogs, owls
Omnivores: eat plants and animals
humans, bears, crows
Detritivores: feed on plant and animal remains and
other dead matter
snails, crabs
Decomposers: obtain energy by breaking down organic
matter
bacteria, fungi
Feeding relationships (who eats who)
Energy flows through an ecosystem in
one direction  from the sun or
inorganic compounds to autotrophs
(producers) and then to various
heterotrophs (consumers).
One way path
Arrows represent the direction the energy moves
Energy is passed from producers through the
ecosystem by a food chain -- series of steps in
which organisms transfer energy by eating and
being eaten
Food chains will form a network through the
ecosystem called a food web
Which organisms are the producers?
What organisms do the marsh hawk eat?
Each consumer relies on the
trophic level below it for energy
Each step in the food
chain or food web is
called a trophic level
- producers make up
the first level
- consumers make up
the second, third,
and higher levels
Food chain ends with top
predator—have few to no
enemies (alligator, hawk, polar
bear)
Producers
Primary consumers
Secondary consumers
3 types
An ecological pyramid is a diagram that shows
the relative amounts of energy or matter in
each trophic level
Organisms use energy they consume for …growth, reproduction,
respiration or energy is lost to the environment
Energy Pyramid: shows the amount of energy available at each
trophic level; greatest amount is found in plants and least is
found in the top level consumers.
- only about 10% of the energy within a level can be
transferred to the next level
10% rule…only
1/10 of energy or
10% is available
to the next
trophic level
Biomass Pyramid: the
total amount of living
tissue within a given
trophic level Expressed in grams
of organic matter
per unit area
Pyramid of numbers:
shows the relative
number of individual
organisms at each level
Ecological Pyramids
Energy Pyramid
Shows the relative amount of
energy available at each trophic
level. Organisms use about 10
percent 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 individual
organisms at each
trophic level.
Section Quiz
The main source of energy for life on Earth is
organic chemical compounds.
inorganic chemical compounds.
sunlight.
producers.
Section Quiz
The main source of energy for life on Earth is
organic chemical compounds.
inorganic chemical compounds.
sunlight.
producers.
Section Quiz
Organisms that feed on plant and animal remains
and other dead matter are
detritivores.
carnivores.
herbivores.
autotrophs.
Section Quiz
Organisms that feed on plant and animal remains
and other dead matter are
detritivores.
carnivores.
herbivores.
autotrophs.
Section Quiz
In a biomass pyramid, the base of the pyramid
represents the mass of
heterotrophs.
primary consumers.
producers.
top level carnivores.
Section Quiz
In a biomass pyramid, the base of the pyramid
represents the mass of
heterotrophs.
primary consumers.
producers.
top level carnivores.
Section Quiz
The amount of energy represented in each
trophic level of consumers in an energy pyramid
is about
10%
90%
10%
90%
of the level below it.
of the level below it.
more than the level below it.
more than the level below it.
Section Quiz
The amount of energy represented in each
trophic level of consumers in an energy pyramid
is about
10%
90%
10%
90%
of the level below it.
of the level below it.
more than the level below it.
more than the level below it.
Are You Smarter Than A 5th Grader?
In this food web, which two organisms could be
harmed if the mouse population were to decline?
A)
B)
C)
D)
Deer and caterpillar
Wolf and snake
Oak and grass
Hawk and songbird
B
Cycles of Matter
Unlike the one-way flow of energy, matter is
recycled within and between ecosystems.
Biogeochemical cycles: the passing of matter
from one organism to another, or one part of
the biosphere to another
Movement of energy is crucial, but
organisms need more than just
energy….water, nutrient, minerals
95% of body is made of O, C, H, N
which are common but not in a
usable form
Matter can cycle through the biosphere because
it is not used up, it is only transformed
The water cycle
Water moves between the ocean, atmosphere,
and land
- evaporation: water changes from liquid to
gas to enter the atmosphere
- transpiration: water
enters the atmosphere by
evaporating from leaves
- precipitation: water
returns to the earth as
rain, snow, sleet, or hail
surface runoff
evaporation
accumulation
(ground water)
underground runoff
(infiltration)
transpiration
precipitation
condensation
Every living organism needs nutrients (bodies
building blocks) to build tissues and carry out
essential life functions.
Food we eat provides energy and
chemicals needed to keep us alive
3 important chemical/nutrient cycles:
C, N, P
Like water, nutrients are passed between
organisms and the environment through
biochemical cycles.
The carbon cycle
Key ingredient of living tissue
Carbon cycles through the biosphere through 4
different kinds of processes:
- biological processes: photosynthesis, cellular
respiration – CO2 is taken in by plants and is
given off by both plants and animals
- geochemical processes: release of CO2 from
volcanoes
- mixed biogeochemical processes: the conversion of
carbon rich remains into coal and oil (fossil fuels);
decomposition (stores C underground)
- human activity processes: mining, burning of fossil
fuels, cutting and burning of forests (releases CO2
into the atmosphere)
Carbon Cycle Game:
http://www.windows.ucar.edu/earth/climate/carbon_c
ycle.html
Carbon is present in atmosphere as CO2 – released by volcanoes,
respiration, and human activities
Plants take in CO2 to build carbohydrates (sugar=food) during
photosynthesis which are taken in by heterotrophs
Eventually, all organism die – returning these nutrients
CO2 in
Atmosphere
CO2 in Ocean
The Nitrogen Cycle
All organisms need nitrogen to make amino acids, the
building blocks of proteins
Many forms of nitrogen occur naturally
-nitrogen gas (N2)– 78% of atmosphere (20% is
oxygen, .93% argon)
-ammonia (NH3), nitrate ions (NO3-), nitrite ions
(NO2-) – found in waste products organisms and dead
and decaying organisms
Limited amount of usable N2  2 atoms of nitrogen is
held together by a triple bond and can only be broken
by lightening, volcanic action, or certain bacteria to
break the bonds
But, not all of this nitrogen is readily
usable by organisms.
certain types of bacteria live in special
structures called nodules on legume
plants
- nitrogen fixation: conversion of
nitrogen gas into ammonia
- other bacteria convert the ammonia into
nitrates and nitrites.
Once ammonia is available…
- producers can then use them to make proteins
- then consumers eat the producers and reuse
the nitrogen to make their own proteins
- when organisms die, decomposers return nitrogen
to the soil as ammonia
- other bacteria convert nitrates and nitrites back
into nitrogen gas through denitrification
Nitrogen Cycle Animation:
http://www.mhhe.com/biosci/genbio/tlw3/eBridge/C
hp29/animations/ch29/1_nitrogen_cycle.swf
N2 in Atmosphere
NH3 Ammonia
NO3and NO2- Nitrate and Nitrite
Ions
Phosphorus Cycle
-essential part of molecules of DNA and RNA
-not very common
-does not enter the atmosphere—remains in rocks,
soil and ocean sediment as inorganic phosphate
-weathering of rocks releases phosphate
-plants take up and use phosphate
Phosphorus Cycle Animation:
http://www.sumanasinc.com/webcontent/ani
mations/content/phosphorouscycle.html
Nutrient Limitation
Primary productivity: the rate at which organic
matter is created by producers
- the availability of nutrients is one factor that
controls primary productivity
Limiting nutrient: a single nutrient that is scarce
or cycles very slowly
to avoid nutrient
limitation farmers will
apply fertilizers If nutrient is in short
supply – organisms
—N, P, K
growth with be limited
– farmers fertilize to
counter act this
•
•
•
•
•
•
Run off carries excess
fertilizers to water
systems
Algal Blooms
When an aquatic ecosystem receives large amounts
of nutrients—runoff from farms—there is an
increase in algae
As more algae and plants grow, others die.
This dead organic matter becomes food for bacteria
that decompose it.
With more food available, the bacteria increase in
number and use up the dissolved oxygen in the
water.
When the dissolved oxygen content decreases, many
fish and aquatic insects cannot survive.
This results in a dead area.
Algal Blooms
Section Quiz
Transpiration is part of the
water cycle.
carbon cycle.
nitrogen cycle.
phosphorus cycle.
Section Quiz
Transpiration is part of the
water cycle.
carbon cycle.
nitrogen cycle.
phosphorus cycle.
Section Quiz
Carbon is found in the atmosphere in the form of
carbohydrates.
carbon dioxide.
calcium carbonate.
ammonia.
Section Quiz
Carbon is found in the atmosphere in the form of
carbohydrates.
carbon dioxide.
calcium carbonate.
ammonia.
Section Quiz
The only organisms that can convert nitrogen in
the atmosphere into a form useful to living
things are nitrogen-fixing
plants.
bacteria.
detritivores.
animals.
Section Quiz
The only organisms that can convert nitrogen in
the atmosphere into a form useful to living
things are nitrogen-fixing
plants.
bacteria.
detritivores.
animals.