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Ecosystems

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									Ecosystems and Their
Interactions
Environmental & Ecology PA
State Standard
4.6.12.ABC
Ecosystems are a fine balance.
 An introduction of
  one species can
  interrupt an entire
  ecosystem.
 In 1988, human
  actions accidentally
  intervened in the
  Great Lakes with the
  introduction of the
  zebra mussel, an
  aquatic shelled
  animal smaller than
  an adult thumb.
Zebra mussel
   They came in
    or on a boat
    from Europe.
    (Most likely in
    the ballast
    water of a
    cargo ship)
Zebra mussel waterway invasion
•Zebra
mussels have
spread
largely due to
boaters
Pros & Cons of zebra mussels
                                   Cons
   Pros                              Grow in clumps and
       Cleanse water of some          clog intake pipes for
        pollutants                     power plants and
                                       municipal water plants.
       Lakes are clearer             Interfere with feeding,
        allowing light to              growth, and
        penetrate deeper for           reproduction of native
        more aquatic plant             mussels
        growth.                       Eat all the
                                       phytoplankton &
                                       zooplankton that are
                                       the foundation of
                                       aquatic food chains
   Ecologists learned that a
    small change (one
    organisms) can have a
    large impact on the entire
    ecosystem, even if it is
    accidental.
   THINK ABOUT THAT
    THE NEXT TIME YOU
    WANT TO RELEASE
    YOUR UNWANTED PET
    INTO THE
    ENVIRONMENT.
Biosphere
   A layer of
    soil, water,
    and air that
    sustains life.
Ecosystem
   Consist of a group
    of living
    organisms that
    interact with one
    another and the
    nonliving physical
    environment as
    one unit
Terrestrial (land) ecosystems


   Forest

   Desert

   Grasslands




   These vary depending climate and soil in the
    area, as well as the type of organisms in it.
Forest Ecosystems
   Common in PA- more than half the state
   Oak-hickory most common in PA 47%
       Largest & most important plants in this
        ecosystem
   Northern hardwoods
     38% of state
     Birch, sugar, maple, beech, & black cherry
Aquatic Ecosystems
   Freshwater ecosystems
       Ponds, lakes, rivers, streams, & wetlands


   Marine ecosystems
       Estuaries, coastal marshes, coral reefs, and
        the open ocean
Hierarchy of ecosystems

1.   Organism: any form of life
2.   Species: a group of organisms alike in several
     ways that can breed
3.   Population: a group of individuals of the same
     species in a given area
4.   Community: populations of living organisms
     that interact with one another in an ecosystem
5.   Ecosystem: living & nonliving interacting
Examples
Habitat
   The place where a particular species lives
    and from which it obtains what it needs for
    survival

   Can be as large as the Atlantic Ocean or
    as small as a rotting log in a hardwood
    forest in northwestern PA
Biotic Factors in an ecosystem
   All living things
     Ex: plants, animals, fungi, & microorganisms
     Can you list some in a PA forest???


   These biotic factors interact with one
    another (predator-prey relationships)
Abiotic factors in an ecosystem
 Nonliving physical and chemical parts of an
  ecosystem
 Although they are nonliving they still greatly
  influence the biotic factors
 Can you think of some abiotic factors on
  land???? How about water?????


   How are they interdependent on one another?
Each species survives best in a
specific range of environmental
conditions
 Remember the macroinvertebrate study
 What types of water did trout prefer?
  Caddisflies? leeches?

 In PA beech trees survive best in shade whereas
  black cherry prefer open sunny locations
 In closed canopies, young black cherries cannot
  survive
Human interaction can disrupt
ecosystems
   Constructing a dam can change the conditions of
    the stream downstream
       They block nutrient rich sediment from going
        downstream because they back up behind the dam
        wall.
       Many plants & animals downstream suffer
       Can block fish from heading upstream to
        reproduce(salmon)
       Alter the temperatures by raising and lowering the
        water level
Human interaction can disrupt
ecosystems

   Concentration of toxic substances in air,
    water, and soil

       Electric Power plants
            Acid rain
Matter & Energy in an ecosystem
   Food chain: the transfer of energy from
    one organism to another

       As one organism eats another organism, that
        energy is transferred
Forest Food Chain
Food Web: A network that shows
many connected food chains
Food chain vs Food web
   A food chain is a linear depiction while a food
    web shows the interconnectedness between all
    the organisms in the food chains

   Regardless, all of the energy begins with the sun
       Plants  photosynthesis  glucose
Producers
   Uses elements from
    the environment to
    make its own food
       Convert solar energy
        to chemical energy
        and store it in their
        cells
Consumer
   An organism gets its
    energy and nutrients
    by feeding on other
    organisms
Different consumers: Herbivore,
carnivore, omnivore
 Primary consumer: feed on plants(herbivores)
 Secondary consumer: feeds on primary
  consumers (carnivore/omnivore)
 Tertiary consumer: feeds on primary &
  secondary consumers
 List some examples of each
Scavengers & Decomposers
   Scavenger: feeds on dead organisms

   Decomposers: usually a type of bacteria or
    fungus that breaks down dead organisms and
    wastes

   These are both important because they
    breakdown wastes in the environment
Trophic levels
   Contains all organisms in a feeding level
    that are the same number of steps away
    from the sun

   As you move up from one trophic level to
    another in an ecosystem, there is a 90%
    loss of energy(as heat)
Trophic levels & energy

   That means only 10% of energy is passed
    from one trophic level to the next.
   Food webs usually have no more than 4-5
    trophic levels
   There is too little energy left to support
    many higher organism (energy pyramid)
Soil- a major part of an ecosystem
   Soil is a precious renewable resource because it
    takes so many years to produce.

   Soils vary from place to place depending on the
    parent material from which it is derived.

   Each layer is called a soil horizon
Soil erosion
   Depends on climate-precipitation
   Human impact-logging, farming

   These factors increase the rate of erosion,
    supporting fewer producers and ultimately
    fewer consumers
Sediment
   Sedimentation- areas
    where large deposit of
    sediment accumulate
       These are fertile area
        because they carry a
        lot of nutrients.
   These can form deltas
Carrying capacity of an Ecosystem

   The number of
    individuals of a
    species that it can
    support
Carrying capacity
   Populations cannot grow indefinitely,
    individuals are born, migrate and or die

   There are many factors which affect these
    processes.
Example
   Adequate rainfall, good weather, leads to
    high production of acorns, which leads to
    more turkeys surviving winter, therefore
    increased reproduction of turkeys.

   Therefore, weather, habitat quality, species
    survival, and reproduction all affect
    population growth.
Limiting factors
   Factors that limit the growth of a population

   This is the most important factor because it
    gives an ecosystem a finite capacity for
    growth
Exponential growth
   A line graph that
    shows exponential
    growth forms a J-
    shaped curve

   This cannot sustain
    itself indefinitely
Carrying capacity
 Population reaches its
  carrying capacity
  forming a S-shaped
  curve
 Grows slowly at first
  then increases more
  & more quickly
  depending on limiting
  factors
Overshooting the carrying capacity
 Deer population explodes
 Eats tons of young shrubs and trees which
  deprives many other forest organisms that rely
  on it

 Some pops will die back, some will migrate to
  another area.
 Many other species will die back before the deer
  would
Habitat & niches
   Habitat is an area where an organism lives
       A forest ecosystem may include tree branches, rotting
        logs, soil, holes in the tree trunks, or spaces under a
        rock

   Niche is the role an organism plays within an
    ecosystem
       Includes the food an organism eats and how it obtains
        its food
       Ex predator/prey diurnal/nocturnal
Niche
   No two species can occupy the same niche in
    one ecosystem.

   If they did for a short time, competition for food,
    water, and space would cause one species to
    eliminate the other.
       Darwin’s Finches
       Modify environment-plant send out toxins to keep
        other plants away
       Beavers build dams and restrict the flow of water
Eastern wood rat
   Knowing an organisms
    niche helps protect it

   Eastern wood rat is
    threatened in PA

   Ecologists are studying its
    niche to try to help
    preserve the species
Exotic species
   Exotic species often
    occupy the same
    niche as native
    species but are better
    able to compete with
    them because the
    exotic species have
    no natural enemies in
    the new ecosystem
Homeostasis
   The natural stability in an ecosystem

   It helps an ecosystem resist transformation and
    helps it recover when stresses are so great that
    they cause serious problems

   Organisms in the ecosystem have the ability to
    resist change, but it is a delicate balance
Ecosystems can bounce back
 Hurricanes and fires occur in areas and
  devastate them
 However, organisms have a way of bouncing
  back but it may change that particular
  ecosystem.

   But some changes are too drastic and it may not
    be able to repair itself.
Biomes
   A geographical region of Earth that is
    inhabited by a community of distinct types
    of plant and associated animal species

   Defined by climate (annual temps and
    precipitation), soils, latitude & altitude
Types of biomes
   Land
   Grassland
   Desert
   Highland
   Ice cap
Land biomes/forests:
Tropical rain forest
 Central SA, Africa, Southeast Asia & N.Australia
 Largest in South America- Amazon
 Heavy rainfall, lush vegetation growing in distinct
  layers
       Lowest layer must adapt to limited sun
 Poor soil-trees’ roots grow laterally to absorb
  nutrients from leaf litter
 Greatest species diversity on Earth-80% of
  species but it covers only 2% of land surface
Land biomes/forests:
Tropical Deciduous/Scrub forest
   A deciduous tree is a tree that survives
    during a cold or dry season by dropping its
    leaves.
   TD is similar to TR but less rain and less
    intensity, trees are less lush and dense
    than TR
   Scrub forests have small deciduous and
    evergreen trees.
Land biomes/forests:
Temperate Deciduous
   Moist areas with long, warm summers and cold
    winters (precipitation all year)

 PA is in this biome
 Dominate trees: oaks, hickories, maples,
  beeches, and sycamores
 Animals: bear, deer, squirrels, rabbits, raccoons
Land Biomes/Forests:
Temperate
   Mid-latitude coastal areas with mild
    winters/ heavy rainfall
   Coniferous forest(cone bearing trees)
    dominate (pines, firs, spruces)

   Oregon, Washington, Canada
Land Biomes/Forests:
Boreal
 Taiga- northern most forest
 Evergreen conifers dominate
       Thin needles of evergreens help tree to survive in the
        cold weather

 Long, cold, dry winters
 Little diversity, poor soil
Grassland Biomes
   Less rain than forests but more than desert
    biomes

   Periodic drought & seasonal fires help
    maintain natural grasslands from shrubs
    taking over
Grassland biome:
Savanna
   Grasslands of the tropic/subtropic
   Warm all year, short wet season, long dry
    season
   Largest in southern Africa, central South
    America, Australia
   Giraffes have specific niche to eat tops of
    trees, zebras grass on ground
Grassland Biome:
Temperate Grassland
 Most interior of North America
 Tall-grass prairie of the Midwest & short-grass
  areas of western Plains

 Winters very cold, summers hot and dry
 Fertile soil due to the upper portion of the grass
  dies off each year
 Corn Belt/ wheat
 Prairie dogs, jackrabbits, squirrels, coyotes,
  wolves, bobcats
Grassland Biome:
Tundra
   AKA: Polar grasslands
   Treeless plains, cold all year, little
    precipitation(snow)
   Plants are well adapted to the cold, waxy
   Mosses, lichens, short shrubs
   Hares, squirrels, and lemmings(thick fur)
Desert
 An area that typically gets less than 10 inches of
  rain each year ( can be hot or cold)
 Tropical: high temps all year low precipitation ex
  southern Sahara
       Sand dunes rock formations
 Temperate:hot summers/cool winters, more
  annual rain ex:Mohave
 Cold:cold winters/hot summers ex: Gobi desert of
  China & Antarctica
Desert Plants
   Special adaptations to extreme
    environment
     Store water
     Succulents have thick, wax coated leaves that
      cut down on moisture loss
     Extensive root systems
   Animals burrow underground to escape the
    heat
Chaparral
   Mild, rainy winters and hot, dry summers

   Southern California, around the Mediterranean
    Sea

 Evergreens with hard leathery leaves
 Prone to wildfires in late summer and fall
       Many seeds need fires to open & sprout seeds
Highland: Mountains
   Temperature drops with elevation
   Depending on windward, precipitation
    changes

   Eastern side drier
Ice caps
   Polar areas that are always cold & where
    snow builds up from year to year into
    enormous ice sheets that cover the land
    surface

   Antarctica and the interior of Greenland
Aquatic Biomes:
Freshwater
   Streams, rivers, lakes, ponds, and
    wetlands that occur inland

   Less conc. of salt
   Pa has all of these

   41% of the world’s fish species live in them
Aquatic biome:
Marine
   Saltwater, the oceans, cover most of the
    Earth
   Estuaries & coastal salt marshes- breeding
    ground for many aquatic animals &
    waterfowl
   Pa does not have an ocean coastline, but
    the southeastern corner borders Delaware
    near the Delaware Bay
Ecosystem Review
Hierarchy of ecosystems

1.   Organism: any form of life
2.   Species: a group of organisms alike in several
     ways that can breed
3.   Population: a group of individuals of the same
     species in a given area
4.   Community: populations of living organisms
     that interact with one another in an ecosystem
5.   Ecosystem: living & nonliving interacting
Habitat
   The place where a particular species lives
    and from which it obtains what it needs for
    survival
Biotic Factors in an ecosystem
   All living things
       Ex: plants, animals, fungi, & microorganisms


   These biotic factors interact with one
    another (predator-prey relationships)
Abiotic factors in an ecosystem
   Nonliving physical and chemical parts of
    an ecosystem
   Although they are nonliving they still
    greatly influence the biotic factors
Producers                           Consumer
   Uses elements from             An organism gets its
    the environment to              energy and nutrients
    make its own food               by feeding on other
       Convert solar energy        organisms
        to chemical energy
        and store it in their
        cells
Different consumers: Herbivore,
carnivore, omnivore

   Primary consumer: feed on
    plants(herbivores)
   Secondary consumer: feeds on primary
    consumers (carnivore/omnivore)
   Tertiary consumer: feeds on primary &
    secondary consumers
Scavengers & Decomposers
   Scavenger: feeds on dead organisms

   Decomposers: usually a type of bacteria or
    fungus that breaks down dead organisms and
    wastes

   These are both important because they
    breakdown wastes in the environment
Trophic levels
   Contains all organisms in a feeding level
    that are the same number of steps away
    from the sun

   As you move up from one trophic level to
    another in an ecosystem, there is a 90%
    loss of energy(as heat)
Exponential growth
   A line graph that
    shows exponential
    growth forms a J-
    shaped curve

   This cannot sustain
    itself indefinitely
Carrying capacity
 Population reaches its
  carrying capacity
  forming a S-shaped
  curve
 Grows slowly at first
  then increases more
  & more quickly
  depending on limiting
  factors
Habitat & niches
   Habitat is an area where an organism lives
       A forest ecosystem may include tree branches, rotting
        logs, soil, holes in the tree trunks, or spaces under a
        rock

   Niche is the role an organism plays within an
    ecosystem
       Includes the food an organism eats and how it obtains
        its food
       Ex predator/prey diurnal/nocturnal

								
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