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Ecology and Our Ecosystem


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Title: Ecology and Our Ecosystem

Ecology and Our Ecosystem
Characteristics of the Biosphere
  • Ecology is the study of organisms and their
    interactions with the environment. (eco-home)
  • The biosphere is the life-supporting region of
    the earth. It includes all the land, air and
    water in which organisms live.

Parts of the environment
  • Abiotic factors- non-living parts of the
  • A-without, bio-life
  • Ex water, soil, light , temperature, wind, and
    physical space.
  • Biotic factors- living parts of the environment.
  • Ex plants, animals and other organisms.

1.43 Understand that and describe how organisms
are influenced by a particular combination of
living and non-living components in the
  • Every species in a habitat has characteristics
    that enable it to function in the unique abiotic
    and biotic factors.
  • It provides the members of a species with food,
    shelter, water, and whatever else they need to

Species, Populations and Communities
  • Species are a group of organisms so similar to
    one another, they can breed and produce fertile
  • Populations are all of the members of a single
    species that live in one area.
  • Populations of different organisms share a living
    space and interact with one another.
  • All of the populations that live and interact in
    one environment make up the community.
  • Can you give an example of a species, population
    and community where you live?

The Ecosystem
  • All of the populations and abiotic factors in an
    area make up the ecosystem.
  • It can be a large (forest, ocean, desert) or
    small area (garden, pond.)
  • Healthy ecosystems are very diverse.

Lets Review the Organization of Life in Ecology
  • From smallest to biggest
  • Organisms- ecologists study behaviors.
  • Populations- ecologists study the effects of them
    on the environment and growth rates.
  • Communities- study the effects on a community
    when new species are added or removed.
  • Ecosystem- ecologists are concerned with the
    stability of the ecosystem.
  • Biosphere- ecologists are concerned with all

  • A niche is the full range of physical and
    biological conditions in which an organisms lives
    and the way in which the organisms uses those
  • An organisms role in the environment.
  • What organism eats
  • how it eats, where lives
  • how reproduces
  • temperatures needed to survive
  • where in food chain,
  • Can two species share a niche in the same
    habitat? Note different tree elevations may be
    different habitats.

Community Interactions
  • Competition occurs when organisms of the same or
    different species attempt to use an ecological
    resource in the same place at same time.
  • Resource is any necessity of life, such as water,
    nutrients, light, food or space.
  • Competition exclusion principle states that no
    two species can occupy the same niche in the same
    habitat at the same time.

Resource Partitioning
  • Some organisms use the same resource as others
    fruit, nuts, fish, light, water, minerals, etc.
  • However, they may share if they use them at
    different times or in different ways.
  • Resource partitioning is a subdividing of some
    category of similar resources that lets competing
    species coexist.
  • Ex. Roots of plants in field. All use same
    resources, but have different roots systems so
    they all can share. Pg. 709

  • Interdependence
  • Organisms rely on their changing environment to
    survive. How? Even a small change to one type of
    organism can have a major impact on all of the
    other organisms in an environment.
  • Predator-prey relationships. (Co-evolution)
  • Symbiosis- different species rely on each other.
    3 kinds.
  • Mutualism- both partners benefit.
  • Commensalism- one partner benefits and the other
    is unaffected.
  • Parasitism- One benefits the other is harmed.
    Which benefits? (40.6)
  • Give examples of each.

Parasite-Host Interactions
  • Only 2 types of interactions kill a host
  • Attacks a host with no coevolved defense against
  • Host all ready has too many parasites on it.
  • Parasitoids- 15 of all insects. They develop
    inside another species of insects, and devours
    from the inside as they mature. They dont
    always kill their host.
  • Larra Wasp, Ormia flies

Social Parasites
  • Animals that take advantage of the social
    behavior of a host species in order to carry out
    their life cycle.
  • Cowbirds lay eggs in another nest and the bird
    feed them.

Adaptations of Prey
  • What are some adaptations prey have to survive?
  • Camouflaging, warning coloration, mimicry

Adaptive Responses of Predators
  • What are some ways that predators counter prey
    defenses with their own adaptations?
  • Stealth (out run), camouflage (wait on them),
    ingenious ways
  • Ex Grasshopper mouse takes the edible beetle
    that sprays chemicals at their predators through
    its end, and puts the beetles end into the ground
    so it cant spray the mouse.

Changes in an Ecosystem
  • Ecosystems can be reasonable stable over hundreds
    of years. If a disaster such as a flood or fire
    occurs, the damaged ecosystem is likely to
    recover in stages that eventually result in a
    system similar to the original one.

Changing with the Environment
  • Ecosystems can be relatively stable over hundreds
    or thousands of years.
  • Changing conditions affect the communities of
    organisms that live in the ecosystem
  • Ecosystems are always changing, sometimes quickly
    and dramatically with a fire or flood or sometime
  • Damaged ecosystems from a flood or fire are
    likely to recover in stages that eventually
    results in a system similar to the original one.

Succession Changes over Time
  • Primary succession is the colonization of new
    sites by communities of organisms after a change
    in the ecosystem. (Volcanoes)
  • 1000s of years
  • After time, primary succession slows down, and
    the community becomes fairly stable.
  • Orderly, natural changes that take place in
    communities of an ecosystem is a succession.
  • What is a pioneer species?

Secondary Succession
  • Secondary succession is the sequence of community
    changes when a community is disrupted by natural
    disasters or human actions.
  • Fewer than 100 years
  • A stable, mature community that undergoes little
    or no succession, is a climax community.
  • Describe a place around you where you have seen
    succession occurring.

Succession in a Marine Ecosystem
  • Large whale dies and sinks to ocean floor and
    attracts scavengers and decomposers.
  • Tissues are eaten by smaller org. Decomposition
    enriches sediments, for other species.
  • Heterotrophic bacteria decompose oil in bones and
    serve as energy sources for chemosynthetic
    autotrophs that support other org.
  • Pg. 96
  • Note Succession can happen in any ecosystem.
  • The following the succession of a whale-fall

Cowbird Chutzpah
  • Cowbirds originally evolved as commenaslists with
    bison (ate insects as kicked up) and as social
    parasites of other bird species in the North
    Amercian Great Plains. When conditions changed,
    the expanded their ranged and now hold power in
    woodlands as well as grasslands of much of the
    US. They parasitize 15 species of native N. A.
    birds today.

Community Instability
  • Keystone species- dominant species that can
    dictate community structure.
  • Geographic dispersal
  • 1. slowly expanding into hospitable regions
    around home
  • 2. Be transported (ships)
  • 3. population moves out from its home range over
    geological time.

Invasive Species
  • In 1988, small freshwater zebra mussels were
    introduced to Lake Erie from Europe.
  • They spread to all great lakes in less than 10
  • They compete with other species for food.
  • They clog up water-intake pipes and
    farm-irrigation pipes.
  • One benefit- filter-feeding action h as made
    water cleaner.
  • Gypsy moths

  • Some species introduced are beneficial
    soybeans, rice, wheat, corn and potatoes

Plants That Ate Georgia!
  • 1876 Kudzu was introduced from Japan to the U.S.
  • In Asia it was well behaved.
  • Kudzu grows up to 60 meters a year.
  • Asians use a starch found in the Kudzu for
    drinks, herbal medicines, and candy.
  • 90 of wallpaper in Asia is made from Kudzu.
  • Goats and herbicides help to maintain it.

Sarah, Alli, Hillary
  • Was used in salt-water aquariums.
  • Imported from Germany.
  • Has covered more than 30,000 hectares of sea
    floor along the Mediterranean Coast.
  • It is now illegal to import alga.
  • Some come into the U.S. with aquatic trade.

Attack of the Bunnies!
  • In the 1800s, British settlers couldnt bond
    with Australias natural critters so they brought
    some bunnies.
  • It first happened in 1859.
  • 6 yrs later a landowner killed 20,000 bunnies.
  • There are 200-300 million bunnies in Australia

  • In 1952, the government introduced the myxoma
    virus that effect the South American rabbits.
  • The European rabbits were also effected.
  • In 1991 researchers released rabbits that had
    been injected with calicivirus.
  • The rabbits died from clots in their lungs,
    heart, and kidneys.

  • In 1995 the virus spread killing 80-95 of adult
    bunnies in Australia.
  • In 1996 it spread to other places.

The sum of all species occupying a specified area
during a specified interval, past as well as
A given area is an outcome of the evolutionary
history of each member species and its resource
requirements, its physiology, and its capacity
for dispersal.
Affected By
Rates of Births, Death, Immigration, and
Which is affected by
Habitat conditions and Interactions among species
The patterns
Patterns have been discovered in biodiversity.
They correspond to differences in the habitat
Mainland and Marine Patterns
The number of species is greater in the tropics
and lessens systematically towards the Poles
Than here
More here
Tropical latitudes get more sunlight, rainfall,
and have a longer growing season. All of which
makes resource availability greater.
Tropical communities have been evolving longer
than temperate ones
Species diversity might be self reinforcing
More trees can exist at the lower altitude. More
plant species compete and coexist. This means
more herbivores can C and C because a greater
diversity of food is available. (i.e. herbivores
that survive on different plants can now live
there) More predators can then C and C because a
greater diversity of food is available. Etc.
Tropical, equator places have more species than
we would. We have more than the North Pole.
Island Patterns
Islands are good land masses to study in
biodiversity. But the number of species will not
increase forever.
The Distance Effect
The further an island from a source of colonizing
species, the less species diversity. The Area
Effect The larger the area for species to live,
the more diversity. Why?
Happens more on smaller islands. The small
populations are more vulnerable to severe storms,
droughts, disease, and genetic drift.
Larger islands equals more species
Threats to Biodiversity
  • 300 mammals on extinction list
  • Habitat loss due to physical reduction of
    suitable places to live and chemical pollution
  • Equilibrium model of island biogeography says
    that 50 loss of habitat will drive about 10 of
    its endemic (specific to region, not introduced)
    species to extinction.
  • Indicator species
  • Overharvesting, overfishing- bad.

Sustaining Biodiversity
  • Hot spots- habitats with the greatest number of
    species found nowhere else are in danger of
  • Ecoregion- Broad land or ocean defined by
    climate, geography and producer species.
    Reservoirs of biodiversity.
  • Protecting biodiversity
  • Strip logging- tropical slopes. Cleared in strips
    (fig. 40.30)
  • Riparian zones (along rivers or streams). Provide
    vegitation and line of defense against flooding.
    Restrict or rotate cattle to prevent ruining the
    vegitation(fig. 40.31)

How Organisms Interact Feeding Relationships
  • Autotrophs- use energy from the sun or stored
    energy to make their own food. They are also
    called producers.
  • All organisms rely on autotrophs for food.
  • Ex plants.
  • Heterotrophs- depend on autotrophs and their
    source of nutrients and energy. They are also
    known as consumers.
  • They include animals.

Photosynthesis vs. Chemosynthesis
  • Chemosynthesis
  • Hydrogen sulfide and oxygen combine to form
    sulfur compounds. Using chemical energy, cells
    make carbohydrates using CO2 from sea water.
  • Where are these bacteria found?
  • Photosynthesis- uses light to make food
  • 6CO2 6H20 ? C6H12O6 6O2

  • Get their energy from the sun through
  • Use light energy to power chemical reactions that
    convert carbon dioxide and water into oxygen and
  • 6CO2 6H2O ? C6H12O6 6O2
  • Chemosynthesis is when organisms use chemical
    energy to produce carbohydrates when there is no
    light present.
  • Bacteria- vents at bottom of ocean is an example.

Photosynthesis vs. Cellular Respiration
  • Photosynthesis Captures energy
  • Chloroplasts
  • 6CO2 6H2O ? C6H12O6 6O2
  • Cellular Respiration
  • Releases energy
  • Mitochondria
  • C6H12O6 6O2 ? 6CO2 6H2O

1.3, 1.4, 1.9, 1.43
Heterotrophs Carnivores and Scavengers
  • Carnivores eat only meat.
  • What are some examples of carnivores?
  • Scavengers eat animals that are already dead,
    they dont kill for food.
  • What are some examples?
  • Why are they important?

  • Eat Plants

Omnivores and Decomposers
  • Omnivores eat both plants and animals.
  • What are some examples?
  • Decomposers are organisms that break down and
    absorb nutrients from dead organisms.
  • Ex bacteria, some protozoans, fungi.
  • Why are they important?

  • Feed on plant and animal remains and other dead
    matter called detritis
  • Earthworms, crabs, mites, snails

Matter and Energy in Ecosystems
  • When you pick an apple from a tree and eat it,
    you are consuming C, N and other elements, and
    well as energy.
  • Matter and energy are constantly cycling through
    the ecosystems.
  • Conservation of mass and energy laws cant be
    created or destroyed. They are transformed into
    different forms.

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Food Chain
  • It is a simple model that scientists use to show
    how matter and energy move through an ecosystem.
  • Nutrients and energy flow from autotroph to
    heterotroph to decomposers.
  • They consist of 3 links, but no more than 5
    because the amount of energy by the 5th link is
    only a small portion. Energy is lost as heat at
    each link.
  • Ex Algae? Fish? Bird

Trophic levels
  • Each organism in a food chain represents a
    feeding step, or trophic level, in the passage of
    energy and materials.
  • They are many routes.
  • 1st level- photosynthetic autotrophs-
  • 2nd level- first order consumers
  • 3rd level- second order consumers (carnivores.)
  • 4th level- third order consumers (carnivores that
    feed on second order carnivores)

1.44 Describe the flow of energy within
Food Webs
  • Food Webs represent a network on interconnected
    food chains.
  • They express all the possible feeding
    relationships at each trophic level in a

DDT in Food Webs
  • Biological Magnification- a substance degrades
    slowly or not at all and becomes more
    concentrated in consumer tissues as it moves to
    higher trophic levels
  • DDtTis a synthetic pesticide that is mostly
    insoluable in water, found anywhere.
  • Wind carries the vapor and water moves it.
  • Highly soluable in fats, and accumulates in
    animals tissue.
  • What it does?
  • disrupts physiology.
  • It is now banned thands to Rachel Carson who
    began the studies of pesiticides.
  • Animals it has had a major effect on pelicans,
    bald eagles and other birds.

Nutrient Limitation
  • Primary productivity is the rate at which organic
    matter is created by producers.
  • Controlled by amount of available nutrients.
  • When an organism is limited by a single nutrient
    that is scarce or cycles slowly, the substance is
    a limited nutrient.
  • Why would this be important to ecologists?

Algal Bloom
  • If there is too much of a limiting nutrient (ie.
    Fertilizer from field) that flows into water,
    this can cause an immediate increase in the
    amount of algae and other producers called an
    algal bloom.
  • Why do they occur?
  • This increases the number of producers, and
    disrupt the ecosystem, if not enough consumers.
  • Eutrophication- too much algae, takes up all of
    the oxygen? things die

Ecological Pyramids- show the relative amounts of
energy or matter contained within each trophic
  • Biomass Pyramid- shows total amount of living
    tissue within a given trophic level.
  • Pyramid of Numbers- shows relative numbers of
    individual organisms at each trophic level.
  • Energy Pyramid- only 10 of the energy available
    within one trophic level is transferred to
    organisms at the next.

Energy Pyramids
  • To construct an energy pyramid for a freshwater
    spring, you must measure the energy transfers in
    each organism and then multiply this by the
    population size.

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Which pyramid is shown?
Some pyramids of energy use numbers to represent
the number of animals/plants there are for each
level. If you had a tree that fed 50,000
insects, what would the pyramid look like? Others
use grams.
Cycling Maintains Homeostasis
  • Matter is constantly recycled.
  • Biological systems do not use up matter, they
    transform it into living tissue, or passed out as
  • Energy is lost as heat to the environment by body
    processes at each level. It flows one way.
  • Sunlight is the source of all energy.
  • Matter also moves through the trophic levels, but
    cant be replinished like sunlight. Recycled

1.44 Describe the flow of matter and nutrients
within ecosystems.
Why do we need the following?
  • Water
  • Carbon
  • Nitrogen
  • Phosphorus

What is the water crisis?
  • Agriculture, drinking water, others?

  • Water- liquid or solid on Earth and gas in the

The water cycle
  • Evaporation of water from water bodies, animals
    and plants.(liquid to gas)
  • Condensation- gas to liquid in form of
  • Transpiration- loss of water vapor from plants.
  • Respiration- gaseous exchange of oxygen and
    carbon dioxide between organisms and environment.
    (Organisms also lose water through excretion.)
  • After an organism dies, decomposition releases
    water back into the environment.

The Carbon Cycle
Carbon Cycle
  • Carbon is found in the environment in the form of
    CO2 in the atmosphere and ocean.
  • From the atmosphere, CO2 moves to aquatic and
    terrestrial producers.
  • Producers use CO2 in photosynthesis to make
    sugar, a higher energy form.
  • Organisms eat C when they consume plants.
  • Respiration returns C to atmosphere in form of
    CO2 and decay returns C to the environment.
  • If decay occurs without O, the C can be bound up
    in a fossil fuels that are burned and returned to
    the atmosphere.

Fossil Fuels Formation
  • Fossil fuels are made when plants and other
    organic organisms die and decompose in the
    ground. Layers upon layers are formed over many
    years. Through chemical processes and pressure,
    fossil fuels are made.
  • 1.42 Sometimes, the environmental conditions are
    such that plants and marine organisms grow faster
    than decomposers can recycle them back to the
    environment. Layers of energy rich organic
    material thus laid down have gradually been
    turned into great coal beds and oil pools by the
    pressure of the overlying earth. Burning these
    fossil fuels, people are passing most of the
    stored energy back into the environment as had
    and release large amounts of CO2.

  • Ammonification- bacteria and fungi break down
    nitrogenous materials, forming ammonium (NH3)
    and either use it or return it to the soil.
    Plants take it up.
  • Nitrification- bacteria turn ammonium into
    nitrite (NO2-) or nitrate (NO3-) by taking away
  • Dentitrificaiton- bacteria take nitrate or
    nitrite and turn it into nitrous oxide (gas).

Nitrogen Cycle
  • Atmospheric N2 makes up nearly 78 of air.
  • Living things cant use N in atmospheric form.
  • Lightning and some bacteria convert atmospheric
    N2 into usable N-containing compounds.
    (nitrogen-fixing bacteria)
  • Plants take up nitrates made from bacteria and
    lightning and convert them into N-compounds.
  • Herbivores eat the plants and convert N-plant
    proteins into N animal proteins.During digestion,
    plant and animal proteins are made into human
  • Organisms return N to the atmosphere when they
    die and decay.(denitrification)
  • Fertilizers from farming are taken up by plants
    or runoff into body of waters.

Nitrogen Cycle
Phosphorus Cycle
Phosphorus Cycle
  • Plants use P from the soil in their body tissues.
  • Animals get P by eating plants.
  • When the animals die, they decompose and the P is
    returned to the soil to be used again.
    (Short-term cycle.)
  • Phosphate washed into the sea become incorporated
    into rock as insoluable compounds. Millions of
    years later, as the environment changes, the rock
    is exposed and made part of the ecological
    system. (long-term cycle.)

Greenhouse Effect- trapping of heat in the
  • CO2, methane water vapor and a few other
    atmospheric greenhouse gases trap heat energy and
    maintain Earths temperature range.
  • Greenhouse effect is the natural situation in
    which heat is retained by the layer of greenhouse

Ozone Layer
  • Band of ozone (O3) that shields the earth from
    much of the suns harmful UV radiation.
  • Thining increases the exposure to UV radiation,
    increasing cataracts and skin cancer and reduce
    crop supply. It may decrease resistance to
  • Causes of thining
  • CFCs (chloroflorocarbons are ordorless,
    noncorrosive compounds that were once used as
    proprellants in aerosol cans and in production of
    plastic foam, coolants in air conditions,
    refrigerators and freezers.

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Global Warming
  • Global warming is is the increase in the Earths
    average temperature.
  • Much of the sunlight that hits the surface of our
    planet is converted into heat energy and then
    radiated back into the atmosphere.
  • Where are some of the gases coming from that are
    causing this effect?
  • Greenhouse gases do not allow heat E to pass out
    of the atmosphere as readily as light energy
    enters it.
  • The gases trap the heat.
  • If these gases were not present in the
    atmosphere, the Earth would be 30oC cooler.
  • In 2050, Earths temp may increase by 2 to 4oC.

Weather and Climate
  • Weather is the day-to-day condition of the
    Earths atmosphere at a particular time and
  • Climate is the typical weather pattern over time
    in an area. (avg. year around temperature)
  • Ecosystems can change with climate changes. Hot,
    cold, rainy, sunny. (1.40b)
  • Can you think of any examples where ecosystems
    have changed with the environment?

Latitude and Longitude
  • Longitude vertical
  • Latitude- horizontal
  • As a result of differences in latitudes and thus
    the angle of heating, Earth has 3 main climate
  • Polar, Temperate and Tropical.
  • Where do you think each are located?

Climate Zones
  • Tropical Zone- equator to 30o N and 30oS
  • Temperate Zone- 30o to 60o N and S latitudes.
  • Arctic (Polar)Zone- beyond 60o N or S latitudes.

Heat Transport in the Biosphere by Winds
  • The unequal heating of the Earths surface drives
    winds and ocean currents, which transport heat
    throughout the biosphere.
  • Winds form because warm air rises and cool air
    sinks. What zones does air rise? Sink?
  • Prevailing winds bring warm or cold air to a
    region, affecting its climate.

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Ocean currents
  • Cold water sinks, warm water rises.
  • Cold water near the poles sinks and then flows
    parallel to the ocean bottom, eventually rising
    again in warmer regions in a process called
  • Surface water is moved by winds.

Why do you think the westerlies move east and
easterlies move west?
  • A biome is a large group of ecosystems that share
    the same type of climate community.
  • Land- Terrestrial
  • Water- Aquatic
  • Microclimate- climate in a small area that
    differs from the climate around it.
  • Fog

(Make graphic organizer for biomes including
climate, flora, fauna, location, other
Biome link
  • Shows two components of climate
  • Temperature and precipitation

San Luis Opispo, California
Biomes are determined by climates (temperature
and precipitation).
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  • Tundra cold and treeless, and most of the soil
    is permanently frozen. A thin layer of soil
    thaws briefly during short, cool, summers.
    Winters are long, dark and very cold.
  • plant life in the tundra consists of mosses and
  • Where do you think tundras are located?
  • Artic Zone
  • Northern N. America, Asia, Europe

Taiga (Boreal Forest)
  • Taiga located south of the tundra, at the
    northern edge of the temperate zone. Winters are
    long, cold, and summers are relatively mild.
  • How are they different from tundras?
  • The taiga climate and soil can support trees such
    as conifers.
  • N America, Asia, and N. Europe

Temperate Forest
  • Grows where summers are pleasantly warm with
    frequent rains, and winters are somewhat cold.
  • What type of trees make up a temperate forest?
  • Tall deciduous trees and coniferous trees.
  • Conifers- seed-bearing cones and needles.
  • Deciduous-sheds leaves during particular season.
  • Eastern US, SE Canada, most of Europe, parts of
    Japan, China and Australia

Chapparral (Temperate Woodland and Shrubland)
  • Warm region that has a rainy winter season,
    followed by a long, dry summer.
  • How do chapperal organisms adapt to these
    extremes in precipitation?
  • Plants are drought-resistant reptiles and
    insects have thick, watertight coverings.
  • W coasts of N and S America, Mediterranean Sea,
    S. Africa, Australia

Tropical Rain Forest
  • Warm, wet weather, lush plant life, and diverse
    animal life. Poor soil
  • What abiotic factors contribute to this
  • Sunlight, water, soil and temperature.
  • Parts of S. and Central America, SE Asia, parts
    of Africa, S India, NE Australia
  • Tropical Dry Forests rainfall is seasonal
    rather than year round. Rich Soil
  • Parts of Africa, S. and Central America, Mexico,
    India, Australia and Tropical Islands

  • Too little precipitation creates deserts, arid
    regions with sparse plant life.
  • Extremely dry, hot deserts may consist only of
    shifting sand dunes. Deserts Africa, Asia,
    Middle East, US, Mexico, S. America, Australia
  • Extremely cold deserts include those is in
    Mongolia and China.
  • How do plants conserve water?
  • Store water in thick, succulent stems.

  • Widespread communities characterized by grasses
    and small plants.
  • Temperate grasslands( summers hot and winters are
    cold and windy)
  • Central Asia, N. America, Australia, central
    Europe, upland plateaus of S. America
  • Tropical savannas (warm year-round and have
    alternating wet and dry seasons.)
  • Large parts of eastern Africa, southern Brazil,
    northern Australia

Other Land Areas
  • Mountain ranges- abiotic and biotic conditions
    vary with elevation.
  • Move up temperature decreases and precipitation
  • Polar ice caps- cold year round.
  • Mosses and lichens grow.
  • Few plants
  • Northern- Polar bears, seals, insects and mites.
  • Southern polar region- 5km of ice. Penguins and
    marine animals.

Marine Biomes
  • Most of the water on earth is salty.
  • Fresh water is confined to rivers, streams,
    ponds, and most lakes.
  • Photic Zone is the portion of the marine biome
    that is shallow enough for sunlight to penetrate.
  • Aphotic Zone- Deeper water that never receives

Water Biomes
  • 3. Wetlands ecosystem where water either covers
    the soil or is present at or near the surface of
    the soil for at least part of the year.
  • Bogs-freshwater wetlands
  • Marshes- shallow wetlands along rivers
  • Swamp- flooded forest
  • 4. Estuary wetlands where fresh water and
    saltwater mix. They form where rivers meet the
    sea and deposit nutrient-rich sediment.
  • detritus- tiny pieces of organic material that
    are food.
  • Salt marshes- temperature zone estuaries
    dominated by low-tide line and seagrasses
  • Coastal Wetlands (mangrove swamps) along
    seacoast that are sometimes mixed with
    saltwater. Florida

Marine Zones
Phytoplankton and algae
Coastal OCEAN Kelp forests
Squids and fishes make their own light.
Bottom-dwellers, sea stars, shrimp, crabs, clams,
worms, urchins, sponges and sea anemones.
Benthic Zone
Marine Ecosystems
  • Intertidal Zone- org. exposed to regular and
    extreme changes. Tides moves. Star fish and
    clams must attach themsevles.
  • Coastal Ocean- extends from low-tide mark to the
    outer edge of the continental shelf.
  • Kelp forests
  • Coral Reefs- calcium carbonate

Marine Ecosystems
  • Open ocean- 500 m to 11,000 m. Low levels of
    nutrients. Octopods, dolphins, whales, fish.
  • Benthic Zone- ocean floor. Cold, dark, pressure
    at bottom

Biosphere Review
  • Click on the following link and choose your text
    book. Review the links and take the self-test.
  • Ch. 3 Review

Characteristics of Populations
  • Geographic distribution
  • Population density
  • Growth rate

Population Size
  • Affected by
  • Number of births
  • Number of deaths
  • Number of individuals that enter or leave a
  • ( immigration vs. emmigration)

Affecting Other Populations
  • Factors that limit one population in a community
    may also have an indirect effect on another
  • Ex lack of water affects the growth of grass,
    reducing the number of seeds produced. The mice
    population have less food, the hawks have less
    food, and so on.

Exponential Growth
  • Exponential growth occurs when the rate of a
    population growth in each new generation is a
    multiple of the previous generation.
  • Bacteria growth lets look at it.
  • Will you work for pennies? Activity.

Growth rate change in number of
individuals Time period
Logistic Growth
  • As resources become less available, the growth of
    a population slows or stops.
  • Logistic growth occurs when a populations growth
    slows or stops following a period of exponential

Exponential Growth Meets the Real World
  • Limiting factor is any biotic or abiotic resource
    in the environment that limits the size of a
  • Carrying capacity is the number of individuals in
    a population that an environment can support over
    a long period of time.

Limiting Factors
  • Environmental factors such as food availability
    and temperature that affect an organisms ability
    to survive in its environment are limiting
  • Limiting factors can be biotic or abiotic factor
    that restricts the existence, numbers,
    reproduction, or distribution of organisms.

Limits on Population Growth
  • Limiting factors either cause a decrease in birth
    rate or an increase in the death rate.

Density-Dependent limiting factors
  • Factors become limiting only when the population
    density ( of org. per unit space), reaches a
    certain level.
  • Gypsy moths and zebra mussels
  • Ex
  • Predation
  • Increase predators- decrease prey
  • Disease
  • More dense population- limited growth
  • Competition
  • Competing for resources

Density- Independent Limiting Factors
  • Factors that affect all populations in the same
    way, regardless of density.
  • Ex
  • Weather
  • Seasonal Cycles
  • Natural Disasters
  • Human Activities

Human Population Growth
  • Human population was very slow for thousands of
  • Between 1650 and 1850 the population doubled,
    passing the 1 billion mark.
  • After 1850, it only took 80 years to double to 2
  • 4 billion 45 years later.
  • It is estimated that the human population in now
    increasing 90 million people a YEAR.
  • Far more people are born than are dying. 3x as

Patterns of Population Growth
  • Demographic Transition- dramatic change in birth
    and death rates.
  • What do you think the trend is now with birth and
    death rates?
  • Age-structure diagrams- graph number of people in
    different age groups in the population.
  • What event is shown in the next age-structure

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What is the future like for population growth?