Ecology

1
Ecology

• Mrs. Morgan
• Biology
• Chapters 3-6

2
Ecology

• Ecology is the scientific study of interactions
  among organisms and between organisms and their
  environment.
• Biosphere
• Biome
• Ecosystem
• Community
• Population
• Species

3
Biomes Ecosystems
Biomes are large areas of the world where there
are similar plants, animals, and other living
things. The living things are adapted to the
climate. Explore the links below to learn more
about different biomes. A biome is made of many
similar ecosystems. In an ecosystem, the plants,
animals, and other organisms rely on each other.
They also interact with non-living parts of the
ecosystem such as the soil, water, and
nutrients. In an ecosystem, each type of plant
and animal has its own role to play.  The role
for one animal might be to climb trees and eat
their fruit, while the role for another animal
might be to hunt for mice.  For a tree, a role
might be to grow tall and make food with the
Suns energy. Sometimes ecosystems get out of
balance. If, for example, it rains a lot and a
type of bird that loves water increases in
numbers, other species in the ecosystem might be
crowded out. The birds might take food or space
from other species.  They might eat all the food.
Sometimes an ecosystem gets back in balance
naturally. Other times an ecosystem will become
more and more out of balance.  Today, human
actions are having an impact on ecosystems all
over the world, sending many ecosystems out of
balance.
Source University Corporation for Atmospheric
Research
4
Food Chain
Grass
Grasshopper
Toad
Snake
Hawk
Bacteria Of Decay
Autotroph Producer
Herbivore 1 Consumer
Carnivores(2, 3, etc. consumers)
Decomposer
Which are the most vital parts of an ecosystem?
Why?
5
Food Web
A food web is a model that shows all the possible
feeding relationships between organisms living in
an ecosystem.
Source Utah State Office of Education
6
Ecology Flow of Energy

• PRODUCERS organisms that make their own food.
• Autotrophs organisms that can capture energy
  from the sunlight or chemicals and use that
  energy to produce food. Plants, some algae, and
  certain bacteria.
• Plants use energy from the sun in a process
  called photosynthesis. During photosynthesis,
  plants use light energy to power chemical
  reactions that convert carbon dioxide and water
  into oxygen and energy-rich carbohydrates such as
  sugars and starches.
• Carbon dioxide Water --------- gt Carbohydrates
  Oxygen
• 6CO2 6H20 --------------- gt C6H12O6 6CO2
• The process where organisms use chemical energy
  to produce carbohydrates is called
  chemosynthesis. Typically this process occurs in
  the absence of light. Several types of bacteria.

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Ecology Flow of Energy

• CONSUMERS - organisms that cannot make their own
  food.
• Heterotrophs organisms that rely on other
  organisms for their energy and food supply. Also
  known as CONSUMERS.
• Herbivore eat only plantscows
• Carnivore eat animalssnakes, dogs, and owls
• Omnivore eat both plants and animalshumans,
  bears, crows
• Detritivores feed on plant and animal remains
  and other dead matter, collectively called
  detritusmites, earthworms, snails, and crabs
• Decomposers break down organic matterbacteria
  and fungi

8
Pyramid of Energy
The Energy pyramid indicates the total amount of
energy present in each trophic level. It also
shows the loss of energy from one trophic level
to the next. An energy pyramid shows clearly that
the energy transfer from one trophic level to the
next is accompanied by a decrease due to waste
and the conversion of potential energy into
kinetic energy and heat energy. The energy
pyramid is more widely used than the others
because comparisons can be made between trophic
levels of different ecosystem. It is, however,
more difficult to compile an energy pyramid than
it is compile the other types of pyramids.
Source http//www.botany.uwc.ac.za/sci_Ed/grade1
0/ecology/trophics/troph.htm
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Energy Pyramid Food Chain
10
Nitrogen Cycle
Source Fundamentals of Physical Geography
11
Nitrogen Cycle
Schematic representation of the flow of Nitrogen
through the environment. The importance of
bacteria in the cycle is immediately recognized
as being a key element in the cycle, providing
different forms of nitrogen compounds assimilable
by higher organisms
Source Environmental Protection Agency.
12
Water Cycle
Earth's water is always in movement, and the
water cycle, also known as the hydrologic cycle,
describes the continuous movement of water on,
above, and below the surface of the Earth. Since
the water cycle is truly a "cycle," there is no
beginning or end. Water can change states among
liquid, vapor, and ice at various places in the
water cycle, with these processes happening in
the blink of an eye and over millions of
years. Although the balance of water on Earth
remains fairly constant over time, individual
water molecules can come and go in a hurry. The
water in the apple you ate yesterday may have
fallen as rain half-way around the world last
year or could have been used 100 million years
ago by Mama Dinosaur to give her baby a bath.
Source Fundamentals of Physical Geography
13
Carbon Cycle
Biological processes, such as photosynthesis,
respiration, and decomposition, take up and
release carbon and oxygen. Geochemical
processes, such as erosion and volcanic activity
release carbon dioxide to the atmosphere an
oceans. Mixed biochemical processes, such as
the burial and decomposition of dead organisms
and their conversion under Pressure into coal and
petroleum (fossil fuels), store carbon
underground. Human activities, such as mining,
cutting, and burning forests, and burning fossil
fuels, Release carbon dioxide into the atmosphere.
Source University Corporation for Atmospheric
Research (UCAR). Biology, Prenctice Hall
14
Oxygen Cycle
Circulation of oxygen in various forms through
nature. Free in the air and dissolved in water,
oxygen is second only to nitrogen in abundance
among uncombined elements in the atmosphere.
Plants and animals use oxygen to respire and
return it to the air and water as carbon dioxide
(CO2). CO2 is then taken up by algae and
terrestrial green plants and converted into
carbohydrates during the process of
photosynthesis, oxygen being a by-product. The
waters of the world are the main oxygen
generators of the biosphere their algae are
estimated to replace about 90 percent of all
oxygen used. Oxygen is involved to some degree in
all the other biogeochemical cycles. For example,
over time, detritus from living organisms
transfers oxygen-containing compounds such as
calcium carbonates into the lithosphere.
Source "oxygen cycle." Encyclopædia Britannica.
2009. Encyclopædia Britannica Online. 04 Aug.
2009 lthttp//www.britannica.com/EBchecked/topic/43
6952/oxygen-cyclegt.
15
Oxygen Cycle

• The overall chemical reaction for photosynthesis
  is
• 6CO2 6H2O ( light energy) C6H12O6 6O2.
• The overall reaction for cellular respiration
  is C6H12O6  6O2   6CO2  6H2O ( energy for the
  cell to use for other things).

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Phosphorus Cycle
The phosphorus cycle is the biogeochemical cycle
that describes the movement of phosphorus through
the lithosphere, hydrosphere, and biosphere.
Unlike many other biogeochemical cycles, the
atmosphere does not play a significant role in
the movements of phosphorus, because phosphorus
and phosphorus-based compounds are usually solids
at the typical ranges of temperature and pressure
found on Earth.
Source wikipedia
Source photo credit Raven, Peter, Linda Berg.
Environment third edition. Harcourt2001
17
Ecosystem

• Biotic
• Living organisms within an ecosystem
• Example human, trees, spider, grass, ants,
  whale, dolphin, clownfish, etc.

• Abiotic
• Nonliving aspects within an ecosystem
• Example air, rocks, dirt, rain, stream, ocean,
  wind, sunlight, etc.

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Habitats and Niches

• Habitat is the physical location where an
  organism lives.
• Example in a tree, in the ocean, in a crack in
  the sidewalk, etc.
• Can more than one organism live in the same
  habitat?

• Niche is the combination of where an organism
  lives, what it eats, how it gets its food, and
  who it mates with.
• Can more than one organism occupy the same niche?

19
Symbiosis

• Symbiosis is any relationship in which two
  species live closely together.
• Mutualism a biological interaction in which
  both species benefit. Pollination, birds in the
  mouth of crocodiles, etc.
• Commensalism a biological interaction where one
  species benefits and the other is unaffected.
  E.coli in our intestines, Clownfish and the sea
  anemone, Cattle egret and cattle, etc.
• Parasitism a biological interaction where one
  species benefits and other is harmed. Fleas,
  ticks, leaches, etc.

20
Tundra
It is not easy to survive in the very cold places
of the world. The soil is frozen and no trees can
grow. This place is called tundra. Plants and
animals that are adapted for cold do live there.
Most tundra is in the north polar region. It is
called Arctic tundra. There is a small amount of
tundra on parts of Antarctica that are not
covered with ice. Plus, tundra is found on
mountains at high altitudes and is called alpine
tundra. Tundra is special because it has
permafrost. Permafrost is frozen ground. The
ground is frozen in the tundra for most of the
year. In the summer, energy from the Sun thaws
the top surface of the ground. Plants grow, but
trees can't because the ground is frozen a few
inches down. Lots of animals go to the tundra in
the summer. Some even stay through the cold
winter!
Source Tundra in the Western Andreafsky
Wilderness of Alaska (U.S.)USGS - Daniel R.
Ruthrauff, photographer
21
Taiga
The taiga biome is full of evergreen forests.
These forests are sometimes called boreal
forests. You can find taiga forests just south of
tundra in the northern parts of Europe, Asia, and
North America. It is very cold and snowy in the
taiga during winter. It is a bit warmer in the
summer. During the summer the days are long, ice
thaws, snow melts, and it is often rainy.
Conifer trees like spruce and fir live in the
taiga. The trees grow close together. This
protects them from cold and wind. There are a few
deciduous trees that can live in the taiga like
birch and aspen, but they are not common. Many
animals make their home in the taiga for at least
part of the year. Some stay year-round. In the
summer, there are lots of birds and insects. Many
bird species migrate to the taiga and breed and
nest there during summer. Other birds, such as
sparrows and crows, stay in the taiga year-round.
Mammals include plant eaters like rabbits and
voles as well as meat eaters such as lynx,
wolverines, and bobcats.
Source Conifer forests of the taiga biome
Image courtesy of Mikhail Dronov of Tomsk in
southwestern Siberia
22
Temperate Forest
The temperate forest biome is found in regions
where winters are cold and summers are warm.
Regions with this climate are common in the
mid-latitudes, far from both the equator and the
poles. Tropical rainforests are in regions that
are consistently warm all year long, close to the
equator. Temperate forests are almost always
made of two types of trees, deciduous and
evergreen. Deciduous trees are trees that lose
their leaves in the winter. Evergreens are trees
that keep their leaves all year long, like pine
trees. Forests can either have deciduous trees,
evergreens, or a combination of both. Another
kind of forest is a temperate rain forest. These
are found in California, Oregon and Washington in
the United States. These forests are made of
redwoods and sequoias, the tallest trees in the
world. The amount of rainfall in an area
determines if a forest is present. If there is
enough rain to support trees, than a forest will
usually develop. Otherwise, the region will
become grassland.
Source Temperate forest in the Great Smoky
Mountains (Tennessee, U.S.) DAAC-Oak Ridge
National Laboratory / NASA
23
Tropical Rainforest
Tropical rainforests are home to thousands of
species of animals, plants, fungi and microbes.
Scientists suspect that there are many species
living in rainforests have not yet been found or
described. There are areas of rainforests where
plants are densely packed. Areas where sunlight
can reach the surface are full of interesting
plants. In other areas a canopy, made from the
branches and leaves of tall trees, shades the
ground below, preventing smaller plants from
growing. Rainforests get their name because
they receive a lot of rain - an average of 80
inches (203 cm) a year! Rainforests are found at
and near the equator, where it is always warm and
muggy. The temperature doesn't change very much
during the year.
Source Rainforest vegetation on the Caribbean
island of Dominica NBII Digital Image Library -
Randolph Femmer, photographer
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Desert
Deserts are full of interesting questions. How
can anything survive in a place with hardly any
water? Why is it so dry to begin with? You can
find at least one desert on every continent
except Europe. Each desert is different in some
way, but they all have one thing in common. In
order for an area of land to be considered a
desert, it must receive less than 10 inches of
water a year. Clouds are scarce in deserts.
Without clouds, there can't be rain, snow, or any
other precipitation. Clouds also shade the land,
so without them, the desert gets mighty hot as
the Sun beats down during the day. At night, the
desert can become very cold, because there isn't
moisture in the air to hold onto the heat. The
geology of each desert is unique. Some deserts
have sand dunes - great waves of sand weathered
from rock, that move over time as wind blows the
sediment. Other deserts have no dunes but instead
have unique rock formations carved by wind and
streams that only flow at times when there is
moisture. Many plants and animals survive in
these vast, dry lands.
Source Mojave Desert (U.S.) NBII Digital Image
Library John J. Mosesso, Photographer
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Grassland
Over one quarter of the Earth's surface is
covered by grasslands. Grasslands are found on
every continent except Antarctica, and they make
up most of Africa and Asia. There are several
types of grassland and each one has its own name.
Prairies, plains and savannas are all grasslands.
Grasslands develop where there isn't enough rain
for forests but too much rain for deserts.
Grasslands are filled with - you guessed it -
grass. There are many types of grass, though.
Fields of wheat are considered grasslands, even
though they are often cultivated by people. Grass
is special because it grows underneath the
ground. During cold periods the grass can stay
dormant until it warms up.
Source Bison roaming on mixed grass prairie, a
type of grassland, at Wind Cave National Park
(U.S.) National Park Service
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Ocean
The ocean holds the largest of Earths biomes. It
covers 70 of the planets surface. Life in the
ocean is diverse. The smallest creatures that
call the ocean home are so tiny that they can
only be seen with a microscope. The largest
creatures are blue whales, which can be as much
as 34 meters (110 feet) long. There are many
different ways to live in the ocean, too. Some
animals travel huge distances through ocean
water. Others stay in the same place on the ocean
floor their entire lives. Some burrow beneath the
sand while others float near the surface.
The ocean is not the same everywhere.  There are
many different ecosystems within the ocean
depending on conditions such as the water
temperature, the amount of sunlight that filters
through the water, and the amount of nutrients.
Sunlight breaks through the top layer of ocean
water. It can make its way as deep as 200 meters
(656 feet). Almost all marine life (about 90)
lives within this top, sunlit layer of the ocean.
There, phytoplankton, algae, and plants like
seagrass make their own food through the process
of photosynthesis and are the start of most
marine food chains. The temperature of ocean
water varies depending on its location. Water
near the polar regions is colder than water near
the equator. Water that is deep in the ocean is
colder than water that is near the ocean surface.
Many animals and other organisms can only survive
at certain temperatures.  Others are able to
survive at a range of temperatures and can live
in more places in the ocean. Source Perch in
giant kelp forest Courtesy of NOAA
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Changes in an Ecosystem

• How do the following changes affect ecosystems?
• Climate
• Human activity
• Introduction of nonnative species
• Changes in population size

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Populations

• There are 3 important aspects of a
  populationgeographic distribution, density, and
  growth rate.
• Population Density is the number of individuals
  per unit area.
• Growth Rate is the number of individuals in a
  given area either increasing in population size
  or decreasing.

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Fluctuations in Population Size

• Birth rate
• Immigration the arrival of new individuals into
  a habitat or population
• Emigration leaving ones native habitat to
  settle into another
• Death rate

Which one(s) cause(s) an increase in population
size? Which one(s) cause(s) a decrease in
population size?
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Exponential Growth

• When a population has unlimited resources and
  under ideal conditions, a population will grow
  exponentially.
• Exponential growth occurs when the individuals of
  a population reproduce at a constant rate.
• What will happen eventually over time?

Source www.agen.ufl.edu
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Logistic Growth

• Do all populations grow exponentially? WHY?
• Resources are not unlimited and this causes
  growth rate to slow down or stop.
• What is a populations carrying capacity?

Source www.geo.arizona.edu
The number of individuals that an ecosystem can
support.
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Predator Vs. Prey
Source Frank Hoppensteadt (2006) Predator-prey
model. Scholarpedia, 1(10)1563
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Defense Mechanisms

• Adaptations that enable organisms to avoid
  predators or give them an advantage against their
  predators
• -camouflage
• -speed
• -trickery (mimicry false features)
• -chemical combat

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Biodiversity

• Biodiversity is the sum total of different kinds
  of organisms. Typically the larger the ecosystem
  the greater the biodiversity. Compare a 7-11 to
  a Ralphs supermarket. Which one has more variety
  and selection? Ok, now relate that to
  ecosystems. Compare a crack in the sidewalk to
  the Pacific Ocean. Which one has more variety
  and selection? Greater Biodiversity.

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Biodiversity (cont)

• Included in the diversity and variety of
  organisms in a specific ecosystem, the
  alterations of habitats of the organisms also
  play a significant role in biodiversity.
• What could alter a habitat? What affect would
  that have on organisms? Ecosystems?