Download Ecology PowerPoint

I. INTRODUCTION
• The earth is home to trillions of different organisms, all of which
cannot survive alone. All organisms (including humans) must
interact with both living and nonliving things that surround them.
• Ecology is the study of how ORGANISMS INTERACT WITH THE
LIVING AND NONLIVING THINGS THAT SURROUND THEM
II. LEVELS OF ORGANIZATION
• The environment is organized into levels, from largest to
smallest:
BIOSPHERE  BIOME  ECOSYSTEM  COMMUNITY 
POPULATION  ORGANISM
• The BIOSPHERE includes the part of the earth that supports
life, and includes some space above and below the earth’s
surface!
• A BIOME is a group of ecosystems that have the same climate
and similar dominant communities (for example, the taiga, desert,
deciduous forest, etc.)
•Ecosystems are made up of BIOTIC FACTORS and ABIOTIC
FACTORS:
BIOTIC
ALL LIVING THINGS THAT
AFFECT AN ORGANISM;
FOR EXAMPLE, BIRDS,
FISH, FLOWERS
ABIOTIC
THE PHYSICAL AND
CHEMICAL
CHARACTERISTICS OF THE
ENVIRONMENT; FOR
EXAMPLE, WATER, SAND,
AND CFC’s
• A COMMUNITY involves all interacting species of an area
(for example, all of the organisms in Colonie)
• A POPULATION includes all of the members of a single
species that live in one place at one time (for example, all of
the frogs in The Crossings Pond in 2005)
• The simplest level of organization in ecology is the
ORGANISM, an individual living thing.
http://www.cals.ncsu.edu/course/ent425/images
/tutorials/ecology/trophic_levels/foodweb.gif
III. ENERGY FLOW
• AUTOTROPH – ORGANISM THAT MAKES ITS OWN FOOD;
SOURCE OF FOOD FOR HETEROTROPHS
• HETEROTROPH – MUST OBTAIN THEIR FOOD FROM THE
ENVIRONMENT; MUST CONSUME OTHER ORGANISMS
• The main source for life on earth is SUNLIGHT, therefore the
AUTOTROPHS, which make their own food using the sunlight
and/or chemicals, are also known as PRODUCERS, because
they not only produce their own food, but provide food to the
HETEROTROPHS
• You see, the heterotrophs EAT the autotrophs, and are
therefore known NOT as producers (because they don’t produce
food), but CONSUMERS
http://weedeco.msu.montana.edu/class/LRES443/Le
ctures/Lecture20/FoodWeb.JPG
•There are different types of heterotrophs:
HERBIVORES
CARNIVORES
OMNIVORES
DETRIVORES
DECOMPOSERS
ONLY
EAT
PLANTS
EAT
ANIMALS
EAT
PLANTS
AND
ANIMALS
FEED ON
REMAINS
AND
DEAD
MATTER
BREAK
DOWN
ORGANIC
MATTER
http://www.alaska-in-pictures.com/data/media/4/eagle-scavenger_836.jpg
http://www.geography4kids.com/files/art/land_chain4_240.jpg
• Energy flows through an ecosystem in one direction, from the
sun or inorganic compounds to AUTOTROPHS to
HETEROTROPHS
• FOOD CHAINS show a series of steps in which organisms
transfer energy by eating and being eaten:
A FOOD WEB shows the complex feeding relationships between
several organisms, and are more intricate than food chains:
• Each step on a food chain or food web is called a TROPHIC
LEVEL
• Each consumer depends on the TROPHIC LEVEL below it
for energy, and AUTOTROPHS are always on the first level
• About 10% of the energy available within one trophic level is
available to the next
• A BIOMASS/ECOLOGICAL PYRAMID illustrates the amount
of living organic matter at each trophic level. Since autotrophs
make their own food and are PRODUCERS, they are the most
numerous organisms, and are ALWAYS found at the BOTTOM
of a biomass/ecological pyramid:
http://ww
w.vtaide.
com/png/
foodweb/
xfoodcha
ins.gif
IV. RECYCLING AND REUSING MATERIALS
• Unlike energy, MATTER is recycled within and between
ecosystems.
• The WATER, CARBON, NITROGEN, and PHOSPHATE cycles
are ways that matter is recycled through ecosystems:
http://www.globalchange.umich.edu/globalchange1/current/lectures/kling/carbon_cycle/carbon_cycle.jpg
V. CLIMATE AND THE GREENHOUSE EFFECT
• Several environmental factors combine to produce weather and
climate.
• Weather – DAY TO DAY CONDITION OF EARTH’S
ATMOSPHERE AT A CERTAIN TIME AND PLACE
• Climate – AVERAGE YEAR TO YEAR CONDITIONS OF A
PARTICULAR REGION
• Greenhouse gases include CARBON DIOXIDE (CO2),
METHANE, WATER VAPOR, AND OTHER GASES
• The greenhouse gases NATURALLY trap heat energy of sunlight
inside the earth’s atmosphere to keep the earth habitable.
• However, many scientists believe that due to human activities
that increase the amounts of certain greenhouse gases, such as
BURNING FOSSIL FUELS AND DEFORESTATION too much of
the greenhouse gases is causing global warming. The carbon
cycle cannot remove the CO2 fast enough!
Sunlight
Some
heat
escapes
into
space
Greenhouse
gases trap
some heat
Atmosphere
VI. HABITAT vs. NICHE
• An organism’s habitat is NOT the same as its niche.
• For example, a bacteria’s habitat may be THE SOIL but
its niche may be as a DECOMPOSER
• You see, an organism’s niche is its ROLE, its occupation
in a certain environment, if you will. An organism’s habitat is
THE AREA WHERE AN ORGANISM LIVES or its
ADDRESS
• The biotic and abiotic factors determine an organism’s
niche. A niche includes the type of FOOD IT EATS, how it
OBTAINS THE FOOD, and which other organism eat the
organism in question.
• RULE: NO TWO SPECIES CAN SHARE THE SAME
NICHE IN THE SAME HABITAT but different species can
occupy niches that are very similar. For example, the
warbler species.
Cape May Warbler
Feeds at the tips of branches
near the top of the tree
Bay-Breasted Warbler
Feeds in the middle
part of the tree
Yellow-Rumped Warbler
Feeds in the lower part of the tree and
at the bases of the middle branches
VII. COMMUNITY INTERACTIONS
A.
Competition
• Competition occurs when ORGANISMS OF THE SAME OR
DIFFERENT SPECIES ATTEMPT TO USE THE SAME
RESOURCE AT THE SAME PLACE AND TIME
• A resource refers to any necessity of life. Think of some of
YOUR resources.
• COMPETITIVE EXCLUSION PRINCIPLE NO TWO
SPECIES CAN OCCUPY THE SAME NICHE IN THE SAME
HABITAT AT THE SAME TIME
http://www.kruger2canyons.com/images/antelopehist.jpg
B. Predation
• Predation is when one organism CAPTURES AND FEEDS
ON ANOTHER ORGANISM
• The killer is the PREDATOR and the killed is the PREY
http://www.biologycorner.com/resources/harelynx.jpg
A dragonfly consumes a plant-feeding stinkbug. The image illustrates prey capture ability and prey defenses, which are
effective against some predators but not others. The photograph was taken by W. Wyatt Hoback in 2003 while in Manaus,
Brazil.
http://tiee.ecoed.net/vol/v4/experiments/insect_predation/img/dragonfly%5BHR%5D.jpg
C. Symbiosis
• Symbiosis means “LIVING TOGETHER”
• There are three types of symbiotic relationships:
1. MUTUALISM – BOTH SPECIES BENEFIT For example,
flowers depend on insects to pollinate them and certain insects
need food…it’s a “win-win”!!
www.nearctica.com/ecology/pops/mutual.htm
2. COMMENSALISM - ONE BENEFITS AND THE OTHER IS
NEITHER HELPED NOR HARMED For example, barnacles
attaching to whale skin. The barnacles benefit because they get
food from the water moving past them, but the whale doesn’t
really care either way, it doesn’t help or harm it!
http://www.mesa.edu.au/seaweek2004/images/whale01.jpg
http://www.learner.org/jnorth/images/graphics/u-z/gwhale_barnacles.jpg
3. PARASITISM – ONE BENEFITS WHILE THE OTHER IS
HARMED Usually, the parasites do not kill their host, but just
weaken it. For example, tapeworms living in the intestines of
mammals. It benefits the tapeworm since it gets food, but can
severely malnourish the host, plus its NASTY!!!! (Saturn cat story)
www.daviddarling.info/images/tapeworm.jpg
http://instruction.cvhs.okstate.edu/JCFOX/HTDOCS/Disk1/Images/Img0059e.jpg
www.vcvikings.com
http://scienceblogs.com/zooillogix/Hookworm.jpg
http://www.notsoboringlife.com/wp-content/uploads/2007/04/roundworms.jpg
http://scienceblogs.com/zooillogix/Hookworm%20Foot.jpg
VIII. ECOLOGICAL SUCCESSION
•Ecosystems are CONSTANTLY CHANGING in response to
natural and human disturbances.
Abiotic Factors
Biotic Factors
ECOSYSTEM
• As an ecosystem changes, older inhabitants gradually die out
and new organisms move in, causing further changes in the
community (think of a fish tank)!
• Ecological succession is the SERIES OF PREDICTABLE
CHANGES THAT OCCURS IN A COMMUNITY OVER TIME
• Succession generally happens SLOWLY (pond changing to a
forest), but can happen FAST (clearing a forest).
http://www.earthhistory.org.uk/wp-content/modernecologicalsuccession.jpg
http://www.scienceclarified.com/images/uesc_10_img0552.jpg
IX. THE MAJOR BIOMES
•Ecologists recognize at least TEN different biomes. Each of
these biomes is defined by a set of abiotic factors (like climate)
and has a characteristic ecological community.
Ten Major Biomes
Biome
Precipitation
Temperature
Soil
Diversity
Trees
Grasses
Tropical Rain Forest
high
hot
poor
high
dense
sparse
Tropical Dry Forest
variable
mild
rich
moderate
medium
medium
Tropical Savanna
variable
mild
clay
moderate
sparse
dense
Desert
low
variable
poor
moderate
sparse
sparse
Temperate
Grassland
moderate
summer hot
rich
moderate
absent
dense
poor
low
medium
medium
Temperate woodland summer low,
summer hot
and Shrubland
winter moderate
Temperate Forest
moderate
summer moderate, rich
winter cold
high
dense
sparse
Northwestern
Coniferous Forest
high
summer mild,
winter cold
rocky, acidic
low
dense
sparse
Boreal Forest
moderate
summer mild,
winter cool
poor, acidic
moderate
dense
sparse
Tundra
low
summer mild,
winter cold
poor
low
absent
medium
X. POPULATION GROWTH
• Three important characteristics of a population are its
GEOGRAPHIC DISTRIBUTIUON, DENSITY, AND GROWTH
RATE
• Geographic distribution – THE AREA INHABITED BY A
POPULATION; RANGE
• Density (aka population density) – NUMBER OF INDIVIDUALS
PER UNIT AREA
• Growth rate – HOW FAST/SLOW IT GROWS
• Three factors that affect population size are:
o # OF BIRTHS
o # OF DEATHS
o # OF INDIVIDUALS IMMIGRATING (ENTERING)
AND EMIGRATING (LEAVING)
•Exponential growth occurs when the individuals in a population
are REPRODUCING AT A CONSTANT RATE; under ideal
conditions with unlimited resources, a population will grow
exponentially.
Exponential growth
Peak population size
Rapid decline
Steady population size
Steady population size
•As resources become less available, the growth of a population
SLOWS OR STOPS
•The largest number of individuals that an environment can
support is called CARRYING CAPACITY of that environment.
Carrying capacity
Time (hours)
CONCEPT MAP ON POPULATION GROWTH:
Population
Growth
can be
Logistic
growth
Exponential
growth
characterized by
No limits on
growth
Unlimited
resources
represented by
Constant
growth rate
J-shaped
curve
characterized by
Limits on
growth
which cause a
Falling
growth rate
represented by
S-shaped
curve
XI. LIMITING FACTORS
• A factor that causes a population’s growth to decrease is
called a LIMITING FACTOR
• Examples of limiting factors include: HUMAN
DISTURBANCES, DISEASE, PREDATION, AMOUNT OF
LIGHT/WATER, COMPETITION
• Limiting factors that depend on population size are called
DENSITY-DEPENDENT LIMITING FACTORS and include
parasitism, disease, competition, and predation.
• Limiting factors that do not depend on population size, since
they will affect all populations in similar ways, regardless of their
size, are called DENSITY-INDEPENDENT LIMITING FACTORS
and include natural disasters, seasonal changes, and human
disturbances.
XII. THE EFFECT OF HUMANS ON THE BIOSPHERE
• Among the human activities that have transformed the
biosphere are HUNTING/GATHERING, AGRICULTURE,
INDUSTRY, AND URBAN DEVELOPMENT
• Environmental resources are classified as being
RENEWABLE OR NONRENEWABLE
o RENEWABLE – CAN REGENERATE AND ARE
REPLACEABLE; TREE, FRESH WATER
O NONRENEWABLE – CANNOT BE REPLENISHED
NATURALLY; OIL, GAS, OTHER FOSSIL FUELS
• SUSTAINABLE USE is a way of using natural resources
without depleting them.
• Human activities affect the SUPPLY AND QUALITY OF
RENEWABLE RESOURCES, such as land, forests, air and
water.
• BIODIVERSITY is one of the Earth’s greatest natural resources.
• Species of many kinds have provided us with FOODS,
INDUSTRIAL PRODUCTS, MEDICINES
• Human activity can reduce biodiversity by:
o ALTERING HABITATS
o HUNTING SPECIES TO EXTINCTION
o INTRODUCING TOXIC COMPUNDS INTO FOOD
WEBS INTRODUCING FOREIGN SPECIES INTO
ENVIRONMENTS
http://www2.warwick.ac.uk/about/environment/faqs/biodiversity.jpg
OZONE DEPLETION – OZONE LAYER THAT PROTECTS US
FROM HARMFUL UV RAYS IS BEING DEPLETED, WHICH
INCREASES THE RISK FOR SKIN CANCER, EYE DAMAGE, ETC.
Ozone absorbs 99% of the harmful ultraviolet (UV) radiation; Most of the
harmful UV radiation will penetrate the atmosphere
http://js082.k12.sd.us/My_Classes/Physical_Science/Phys_Sci_ch_7/ozone_3.jpg&imgrefurl=http://js082.k12.sd.us/My_Classes/Physical_Science/Phys_Sci_ch_7/ozone_layer_depletion.htm&h=289
&w=288&sz=14&hl=en&start=2&sig2=GuPYrwgVnTwRtUn7S4p6Xw&tbnid=Jcf6inn5WEv__M:&tbnh=115&tbnw=115&ei=qRZESMHbFpXWesTM0LoE&prev=/images%3Fq%3Dozone%2Bdepletion
%26gbv%3D2%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DG
GLOBAL WARMING - INCREASED GREENHOUSE GASS IN THE
ATMOSPHERE IS TRAPPING HEAT AND THUS INCREASING
EARTH’S TEMP.
naturematters.wordpress.com/2006/11/
CONCEPT MAP ON HUMAN ACTIVITIES:
Human
Activities
that have changed the biosphere include
Hunting and
gathering
may have once caused
Industrial
growth
Agriculture
often relies on the methods of the
Extinctions of
large animals
Green
revolution
Food supply
Pesticide use
have resulted in
High standard
of living
which increased
Monoculture
use
Urban
development
Increased
pollution