Ecosystems and Biomes

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Ecosystems and Biomes

• Chapter 2 Section 1
• Energy Flow in Ecosystems

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Objectives

• After completing the lesson, students will be
  able to
• Describe the energy roles of organisms in an
  ecosystem
• Explain food chains and food webs
• Describe how much energy is available at each
  level of an energy pyramid.

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Energy Roles

• An organisms energy role is determined by how it
  obtains energy and how it interacts with the
  other living things in its ecosystem.
• An organisms energy role in an ecosystem may be
  that of a producer, consumer, or decomposer.

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Producers

• Energy first enters most ecosystems as sunlight.
• ProducerAn organism that can make its own food.
• Producers are the source of all the food in an
  ecosystem.
• Examples grass and oak trees.

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Consumers

• ConsumerAn organism that obtains energy by
  feeding on other organisms.
• HerbivoresConsumers that eat only plants
• CarnivoresConsumers that eat only animals
• OmnivoreEats both plants and animals
• ScavengerA carnivore that feeds on the bodies of
  dead organisms.

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Decomposers

• DecomposersOrganisms that break down wastes and
  dead organisms and return the raw materials to
  the environment.
• Two major groups of decomposers are bacteria and
  fungi

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Food Chains and Food Webs

• Food chainA series of events in which one
  organism eats another and obtains energy.
• 1stProducer
• 2ndFirst-Level Consumer
• 3rdSecond-Level Consumer
• Food WebConsists of many overlapping food chains
  in an ecosystem.

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Energy Pyramid

• When an organism in an ecosystem eats, it obtains
  energy. The organism uses some of its energy to
  move, grow, and reproduce, and carry out other
  life activities.
• This means that only some of the energy will be
  available to the next organism in the food web.

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Energy Pyramid

• Energy PyramidShows the amount of energy that
  moves from one feeding level to another in a food
  web.
• The most energy is available at the producer
  level. At each level in the pyramid, there is
  less available energy than at the level below.
• An energy pyramid gets its name from the shape of
  the diagramwider at the base and narrower at the
  top, resembling a pyramid.
• In general, only about 10 of the energy at one
  level of a food web is transferred to the next,
  higher, level. The other 90 is used for the
  organisms life processes or is lost as heat to
  the environment.

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Energy Pyramid

• Since 90 of the energy is lost at each step,
  there is not enough energy to support many
  feeding levels.
• Organisms at higher feeding levels of an energy
  pyramid do not necessarily require less energy to
  live than organisms at lower levels. Since so
  much energy is lost at each level, the amount of
  energy in the producer level limits the number of
  consumers the ecosystem can support. As a
  result, there usually are few organisms at the
  highest level in a food web.

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Ecosystems and Biomes

• Chapter 2 Section 2
• Cycles of Matter

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Objectives

• After completing the lesson, students will be
  able to . . .
• Describe the three major processes that make up
  the water cycle
• Describe the carbon-oxygen cycle and the nitrogen
  cycle

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Recycling Matter

• The supply for matter is limited, which means
  there isnt much of it.
• If matter could not be recycled, ecosystems would
  quickly run out of the raw materials necessary
  for life.
• Energy, on the other hand, is not recycled

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Recycling Matter

• Matter cycles through an ecosystem over and over.
• Matter in an ecosystem includes water, oxygen,
  carbon, nitrogen, and many other substances.

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The Water Cycle

• Water is necessary for life as we know it.
• Water cycleThe continuous process by which water
  moves from Earths surface to the atmosphere and
  back.
• The process of evaporation, condensation, and
  precipitation make up the water cycle.

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Evaporation

• EvaporationThe process by which molecules of
  liquid water absorb energy and change to the gas
  state.
• Liquid water evaporates from Earths surface and
  forms water vapor, a gas, in the atmosphere.
• Most water evaporates from oceans and lakes.
• Water is also produced through living things
  plants release water vapors from their leaves,
  people release water through waste and water
  vapor when they exhale.

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Condensation

• CondensationThe process by which a gas changes
  to a liquid.
• As water vapor rises higher in the atmosphere, it
  cools down. When it cools to a certain
  temperature the vapor turns back into tiny drops
  of liquid water.

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Precipitation

• PrecipitationRain, snow, sleet, or hail.
• As more water condenses, the drops of water in
  the clouds grow larger and heavier, eventually
  falling back down to Earth.

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The Carbon and Oxygen Cycles

• Carbon is the building block for the matter that
  makes up the bodies of living things.
• Producers take in carbon dioxide from the
  atmosphere during photosynthesis.
• In this process, the producers use carbon from
  the carbon dioxide to produce other
  carbon-containing molecules.
• At the same time, oxygen is also cycling through
  the ecosystem.

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The Nitrogen Cycle

• Nitrogen gas is called free nitrogen, meaning
  it is not combined with other kinds of atoms.
• Most organisms can use nitrogen only once it has
  been fixed, or combined with other elements to
  form nitrogen-containing compounds.

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The Nitrogen Cycle

• Nitrogen Fixation
• Nitrogen fixationThe process of changing free
  nitrogen gas into a usable form of nitrogen.
• NodulesBumps on the roots of certain plants that
  house nitrogen-fixing bacteria.
• These plants, known as legumes, include clover,
  beans, peas, alfalfa, and peanuts.

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The Nitrogen Cycle

• Return of Nitrogen to the Environment
• Once the nitrogen has been fixed into chemical
  compounds, it can be used by organisms to build
  proteins and other complex substances.
• Decomposers break down complex compounds in dead
  organisms and returns simple nitrogen compounds
  back into the soil.
• Eventually, bacteria breaks down the nitrogen
  compounds completely and release free nitrogen
  back into the air. Then the cycle starts again.

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Ecosystems and Biomes

• Chapter 2 Section 3
• Biogeography

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Objectives

• After completing the lesson, students will be
  able to . . .
• Describe some different means that disperse
  organisms
• Identify the factors that limit the distribution
  of a species

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Biogeography

• BiogeographyThe study of where organisms live.
• Bio life
• Geo Earth
• Graph Description

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Continental Drift

• Continental DriftThe very slow motion of the
  continents.
• All of todays continents were once together in a
  large landmass known as Pangaea. Slowly, the
  continents started to drift apart to where they
  are presently located.
• The movement of the continents has had a great
  impact on the distribution of species.

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Means of Dispersal

• DispersalThe movement of organisms from one
  place to another.
• Dispersal can be caused by wind, water, or living
  things, including humans.

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Wind and Water

• Wind provides a means of dispersal fro seeds, the
  spores of fungi, tiny spiders, and many other
  small, light organisms.
• Water transports objects that float in which
  organisms, such as insects, get a free ride to
  another location.

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Other Living Things

• Example
• A goldfinch may eat seeds in one area and deposit
  them elsewhere in its waste.
• A duck may carry algae or fish eggs on its feet
  from pond to pond.
• Dogs and cats can carry sticky plant burs that
  attach to their fur.
• Humans intentionally/unintentionally transports
  organisms from one region to another.

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Other Living Things

• Native SpeciesSpecies that have naturally
  evolved in an area.
• Exotic SpeciesSpecies that has been carried into
  a new location by people

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Limits to Dispersal

• Three factors that limit dispersal of a species
  are physical barriers, competition, and climate

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Limits to Dispersal

• Physical Barriers
• Water
• Mountains
• Deserts
• Competition
• When an organism enters a new area, they have to
  compete for resources. Organisms have to have a
  unique niche in order to survive.

• ClimateThe typical weather in an area over a
  long period of time.
• The different types of climate can limit the
  number of organisms that can inhibit an area.

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Ecosystems and Biomes

• Chapter 2 Section 4
• Earths Biomes

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Objectives

• After completing the lesson, students will be
  able to . . .
• List and describe Earths major land biomes
• List and describe Earths major freshwater and
  ocean biomes

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Biomes

• BiomeA group of ecosystems with similar climates
  and organisms.
• It is mostly the climate conditionstemperature
  and rainfallin an area that determine its biome.

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Rain Forest Biomes

• Climate of Rain Forests warm and humid
• Tropical Rain Forests
• Found close to the equator
• Receive lots of rain
• Sunlight is fairly constant
• The abundant plant life provides many habitats
  for animals
• Contain more species of plant an animals than all
  the other land biomes combined.

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Rain Forest Biomes

• CanopyA leafy roof formed by tall trees.
• UnderstoryA layer of shorter plants that grow in
  the shade of a forest canopy.

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Canopies and Understories
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Rain Forest Biomes

• Climate of Rain Forests warm and humid
• Temperate Rain Forests
• Too far north and too cool to be a tropical rain
  forest
• The term temperate means moderate temperature

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Desert Biome

• DesertAn area that receives less than 25
  centimeters of rain per year.
• The organisms that live in the desert are adapted
  to the lack of rain and to the extreme
  temperatures.
• Many desert animals are most active at night when
  the temperatures are cooler.

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Grassland Biome

• GrasslandAn area that receives between 25-75
  centimeters of rain each year, and is typically
  populated by grasses and other non-woody plants.
• SavannasGrasslands that are located closer to
  the equator than prairies.
• Grasslands are home to many of the largest
  animals on Earth.

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Deciduous Forest Biomes

• Deciduous treesTrees that shed their leaves and
  grow new ones each year.
• Example Oaks and Maple trees
• Receive enough rain to support the growth of
  trees and other plants
• The growing season usually lasts five to six
  months.
• The variety of plants in the forest creates many
  different habitats

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Deciduous Forest Biomes

• If you were to return to this biome during the
  winter, you would not see much of the wildlife
  that you are able to observe during the warm
  temperatures.
• HibernationA low-energy state similar to sleep.
• During hibernation an animal relies on fat it has
  stored in its body.

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Boreal Forest Biomes

• Coniferous treesTrees that produce their seeds
  in cones and have leaves shaped like needles.
• Sometimes referred by its Russian name Taiga
• Winters are very cold

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Boreal Forest Biomes

• Yearly snowfall can reach heights well over your
  head
• A limited number of trees have adapted to the
  cold climate
• Prevention of water loss is a necessary
  adaptation for trees
• Many of the animals found here eat the seeds
  produced by the conifers

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Tundra Biome

• TundraAn extremely cold, dry, land biome.
• PermafrostThe frozen soil found in the Tundra

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Tundra Biome

• Plants on the tundra include mosses, grasses,
  shrubs, and dwarf forms of a few trees, such as
  willows.
• Most of the plant growth takes place during the
  long summer days when many hours of sunshine
  combine with the warmest temperature.

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Mountains and Ice

• The climate conditions of a mountain change from
  its base to its summit.
• As a result, different species of plants and
  other organisms inhabit different parts of the
  mountain

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Freshwater Biomes

• Water biomes include both freshwater and
  saltwater (also called marine) biomes
• All of these are affected by the same abiotic
  factors Temperature, sunlight, oxygen, and salt
  content
• Because water absorbs sunlight, there is only
  enough light for photosynthesis near the surface
  or in shallow water.

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Ponds and Lakes

• Ponds and lakes are bodies of standing, or still,
  fresh water.
• Lakes are generally larger and deeper than ponds.
• Ponds are often shallow enough that sunlight can
  reach the bottom

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Streams and Rivers

• Animals that live in this part must be adapted to
  the strong current
• Few plants and algae can grow in this fast-moving
  water
• Different organisms are adapted to live in this
  lower part of the river.

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Estuaries

• EstuaryAn area found where the fresh water of a
  river meets the salt water of the ocean.
• The shallow, sunlit water, plus a large supply of
  nutrients carried in by the river, makes an
  estuary a very rich habitat for living things
• Major producers plants and algae

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Intertidal Zone

• Intertidal ZoneThe part of the shore between the
  highest high-tide line and the lowest low-tide
  line.
• Organisms here must be able to withstand the
  pounding action of waves, sudden changes in
  temperature, and being both covered with water
  and then exposed to the air.

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Neritic Zone

• Neritic ZoneThe region of shallow ocean water
  over the continental shelf.
• Many large schools of fish feed on the algae, and
  the formation of coral reefs may occur in the
  Neritic Zone.

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Ecosystems and Biomes

• Chapter 2 Section 5
• Succession

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Objectives

• After completing the lesson, students will be
  able to . . .
• Describe the differences between primary and
  secondary succession

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Succession

• SuccessionThe series of predictable changes that
  occur in a community over time.
• Examples Fires, floods, volcanoes, hurricanes,
  and other natural disasters.

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Primary Succession

• Primary successionA series of changes that occur
  in an area where no ecosystem previously existed.
• Such an area might be a new island formed by the
  eruption of an undersea volcano, or an area of
  rock uncovered by a melting sheet of ice.
• Pioneer SpeciesThe first species to populate an
  area.

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Secondary Succession

• Secondary SuccessionA series of changes that
  occur after a disturbance in an existing
  ecosystem.
• Natural disturbances that have this effect
  include fires, hurricanes, and tornadoes.
• Human activities, such as farming, logging, or
  mining, may also disturb an ecosystem.
• Unlike primary succession, secondary succession
  occurs in a place where an ecosystem has
  previously existed.
• Secondary succession occurs somewhat more rapidly
  than primary succession.