Download Ecology

Ecology
Chapters 3,4 & 6
3.1 What is ecology?
 Ecology- the scientific study of interactions
among organisms and between organisms
and their environment.
*Turn to your partner and describe an
“interaction” between two organisms.
Now describe an example of an organism
“interacting” with its environment.
3.1 What is ecology?
 Studying ecology can be as simple as
examining a single organism, or as
complex as the biosphere.
 Biosphere- contains all of Earth including
the land, water, air, atmosphere and all of
the organisms on Earth.
3.1 What is ecology?
 Scientists can study the following levels of
organization from most simple to most
complex:
1. Individual organism
2. Species-A group of organisms that is
genetically similar and can breed together
to produce fertile offspring.
3. Populations-A group of the same species
that live in the same area (ex. a herd)
3.1 What is ecology?
4. Communities- several populations in the
same area (ex. Different herds/packs in the
same state).
5. Ecosystem-all of the organisms that live
in a specific place along with all of their
physical (nonliving) environment.
6. Biome- a group of ecosystems that have
the same climate and similar organisms.
*Can you think of some examples of
biomes?
Excellent!
 Pics of biomes
3.2 Energy flow
Autotrophs vs.
Organisms that can
take energy from the
sun.
Known as producers
Go through
photosynthesis and
cellular respiration to
release energy from
sun.
Heterotrophs
Organisms that must
consume other
organisms for their
energy.
Known as consumers
Go through cellular
respiration to release
energy from other
organisms.
3.2 Energy flow
Food for thought: Are you
considered an autotroph if you
are a vegetarian?
3.2 Energy flow
Food Chains vs.
A series of steps in which
organisms transfer energy
by eating and being
eaten.
Simple
Food Webs
The feeding relationships
between various
organisms which forms a
network of complex
interactions.
Complex
3.2 Energy flow
3.2 Energy flow
3.2 Energy flow
 Trophic level-is each step in a food
chain/web.
 Producers always make up the first trophic
level. Consumers make up the second,
third, etc.
Why do you think producers always come
first?
3.2 Energy flow
 10% Rule- Only about 10% of the energy
available within one trophic level is
transferred to an organism at the next
trophic level.
 About 90% of the energy is lost as heat
energy at each trophic level!
3.2 Energy flow
 The 10% rule can be seen easily as a pyramid.
3.2 Energy flow
3.2 Energy flow
 The 10% rule also
applies to
biomass.
 Biomass- the total
amount of living
tissue within a
given trophic level.
3.2 Energy flow
 Plants and algae form the bottom of the
pyramid because there are more of them
on Earth (they can acquire energy from
the sun more efficiently than by eating
other organisms).
 Conservation of energy- Energy can
neither be created or destroyed (its just
lost as heat!).
3.3 Cycling of Matter
 Unlike energy matter is recycled within
and between ecosystems.
 Matter-is any substance that takes up
space. (even as small as an atom)
 Matter such as: water, carbon, nitrogen
and phosphorus are cycled between the
land, atmosphere and organisms.
How could water cycle in this way? Write
down an example.
3.3 Cycling of Matter
3.3 Cycling of Matter
 Carbon is a key element for storing
energy for all organisms in the form of
carbohydrates.
 Carbon can be found in the atmosphere
and oceans as CO2 .
 Consumers need plants to convert the CO2
in the atmosphere to carbohydrates.
3.3 Cycling of Matter
How do organisms
acquire energy from
carbohydrates?
 They break the
bonds in between
the carbons.
4.2 What Shapes an Ecosystem?
 Most organisms find or evolve into a niche
to avoid too much competition.
 A niche- is the full range of physical and
biological conditions which an organism
lives and the way in which the organism
uses those conditions.
4.2 What Shapes an Ecosystem?
 For example:
4.2 What Shapes an Ecosystem?
 Organisms that live in the same
communities also interact in many ways,
much like you interact with neighbors.
 Some of the categories of interactions are:
Competition, predation, symbiosis,
mutualism, commensalism and parasitism.
4.2 What Shapes an Ecosystem?
1. Competition- occurs when organisms of
the same or different species attempt to
use the same ecological resource at the
same time. (table in notes: interaction,
human example, animal example)
2. Predation- one organism captures and
feeds on another organism.
4.2 What Shapes an Ecosystem?
3. Symbiosis- two species live closely
together.
a. mutualism- both species benefit from
the relationship.
b. commensalism- one member benefits
the other is not helped or harmed.
c. Parasitism- one organism lives on or
inside the other and harms it.
4.2 What Shapes an Ecosystem?
 Main idea: these interactions between
different organisms and their environment
can affect the size of their population.
5.1 How Populations Grow
Exponential
Growth vs.
Occurs when
individuals reproduce
at a constant rate
Usually occurs under
ideal conditions with
unlimited resources.
Logistical Growth
Occurs when a
population’s growth
slows or stops after a
period of exponential
growth.
Limited by carrying
capacity- the max
number of individuals
an environment can
support.
5.1 How Populations Grow
Exponential Growth
5.1 How Populations Grow
Logistical Growth
5.1 How Populations Grow
5.1 How Populations Grow
 Food for thought: If the rate of
reproduction is constant, then why does
the population shoot up over time?
 What are some factors that might limit
population growth in a logistic growth
pattern?
6.3 Biodiversity
 Biodiversity- the sum total of the
genetically based variety of all organisms
in the biosphere.
a. Ecosystem diversity- the variety of
habitats and communities in the world.
b. Species diversity- the number of different
species in the world.
c. Genetic diversity- all of the ways that
organisms differ genetically (within their
DNA).
6.3 Biodiversity
Why do we need a variety of organisms on
Earth?
 Provide humans with food, products,
clothing, medicines, etc.
 When one species becomes extinct it may
affect many other species (think food
web!).
 When a species becomes extinct we will
never know its hidden potential (i.e.
drugs).
6.3 Biodiversity
Human activity can reduce biodiversity by:
Give an example of eacha. Altering habitats
b. Hunting to extinction
c. Introducing toxins to a food web
d. Introducing foreign species
6.3 Biodiversity
a. Altering habitats- when humans/nature
alters or destroys the habitat that an
organism lives in.
6.3 Biodiversity
b. Hunting to extinction
 Now illegal to hunt to extinction.
 Hunting protected species is called
poaching.
 Ex: carrier/passenger pigeons hunted to
extinction in early 1900’s.
6.3 Biodiversity
Extinct
species
Both
(pg. 151)
Endangered
species
6.3 Biodiversity
c. Pollution/toxins
 Many forms of pollution can affect
biodiversity such as smog, acid rain,
garbage and agricultural runoff.
 Biological magnification- when
concentrations of harmful substances
increase in higher trophic levels. Example:
DDT pesticide.
6.3 Biodiversity
d. Introduced species
 Humans sometimes unknowingly transport
food/plants/animals from other parts of
the world, which can upset the local food
web.
 Sometimes organisms are purposely
introduced to control another species.
 Invasive species- Organisms that when
introduced to a new habitat reproduce
rapidly and threaten local species.
 Invasive species
6.3 Biodiversity
 Food for thought: What could cause a
species to grow exponentially in a new
habitat when they did not in their habitat?
6.3 Biodiversity
 Example of invasive species: Zebra
muscles. Arrived via ship into the Great
Lake in the 1980’s.
6.3 Biodiversity
What can we do to protect biodiversity?
 Conservation- wise management of
natural resources including the
preservation of habitats and wildlife.
6.3 Biodiversity
Strategies for Conservation:
a. Protecting entire ecosystems
b. Captive breeding programs (zoos)
c. Protected areas- national/state parks
d. Ban hunting of endangered species
e. Enforce environmental laws
6.3 Biodiversity
Challenges:
a. Financial hardship on businesses (catch
22 because if not protected may not be
there to use, i.e. fishing industry).
b. Economic costs to enforce laws.
6.4 The Future
 Today much of the Earth’s land surface
has been altered by human activities.
6.4 The future
 One major change is a decrease in the
ozone layer.
 The ozone layer is a concentration of
gases about 20-50 kilometers above the
Earth.
 It helps protect the Earth against some of
the UV radiation from the sun.
6.4 The Future
 In the 1970’s it was discovered that a
product called CFC’s were responsible for
much of the damage done to the ozone
layer.
 CFC’s were banned in products like
hairsprays and refrigerators.
6.4 The Future
 Another way humans have affected the
biosphere is through greenhouse gases.
 Greenhouse gases are pollutants released
by cars, factories and homes such as:
Carbon dioxide, methane and water vapor.
 When these gases are released into the
atmosphere they can form a layer around
the Earth which traps the sun’s heat close
to the surface. This is called the
greenhouse effect.
6.4 The Future
 Greenhouse effect and global warming.
6.4 The Future
So what if it gets warmer, I like summer!
 Melting glaciers= sea levels will rise.
Which means…
 Increased temperatures= affects growing
season.
Which means…
 Some organisms may not be able to adjust to
their new climate.
Which means…
6.4 The Future
Partner up and brainstorm 3 ways that
humans can
a. Decrease our affect on the environment
b. Fix the damage that has already been
done.