Post on 21-Jan-2016
transcript
CHAPTER 2 – CHAPTER 2 – PRINCIPLES OF PRINCIPLES OF
ECOLOGYECOLOGY
Section 2-2: Nutrition and Energy Section 2-2: Nutrition and Energy Flow (p.46-57)Flow (p.46-57)
How Organisms Obtain EnergyHow Organisms Obtain Energy An important An important
characteristic of a characteristic of a species niche is how it species niche is how it obtains obtains ENERGYENERGY
Ecologist trace the flow Ecologist trace the flow of energy through of energy through communitiescommunities to discover to discover nutritional relationships nutritional relationships between organismsbetween organisms
How Organisms Obtain EnergyHow Organisms Obtain Energy The ultimate source of energy The ultimate source of energy
for life is the for life is the SUNSUN Plants use the sun’s energy Plants use the sun’s energy
to manufacture food in a to manufacture food in a process called process called PhotosynthesisPhotosynthesis
AutotrophsAutotrophs An organism that uses light An organism that uses light
energy or energy stored in energy or energy stored in chemical compounds to chemical compounds to make energy-rich make energy-rich compoundscompounds Also called a Also called a producerproducer Examples:Examples:
• GrassGrass• TreesTrees• AlgaeAlgae
HeterotrophsHeterotrophs An organism that An organism that
cannot make its cannot make its own food and own food and feeds on other feeds on other organismsorganisms
Can feed on Can feed on autotrophsautotrophs or or other other heterotrophsheterotrophs
HerbivoreHerbivore A heterotroph A heterotroph
that only feeds that only feeds on plantson plants
Examples:Examples:
CarnivoresCarnivores A heterotroph A heterotroph
that only eats that only eats other other heterotrophsheterotrophs
Examples:Examples:
ScavengersScavengers
Do not kill for foodDo not kill for food Eat already dead Eat already dead
animalsanimals Examples:Examples:
Role benefits Role benefits ecosystems – ecosystems – recycles nutrientsrecycles nutrients
OmnivoresOmnivores Organisms that eat Organisms that eat
both plants and both plants and animalsanimals
Examples:Examples:
DecomposersDecomposers
Break down the Break down the complex complex compounds of compounds of dead and decaying dead and decaying plants and animalsplants and animals Nutrient recyclingNutrient recycling
Examples:Examples:
Flow of Matter and Energy in Flow of Matter and Energy in EcosystemsEcosystems
As you eat food, such as an apple, you As you eat food, such as an apple, you consume consume MatterMatter
Matter flows through the levels of an Matter flows through the levels of an ecosystemecosystem from producers to consumers from producers to consumers
Food ChainFood Chain A simple model that scientists use to show how A simple model that scientists use to show how
matter and energy move through an ecosystemmatter and energy move through an ecosystem Example:Example:
A portion of energy is given off as A portion of energy is given off as HEATHEAT
Trophic LevelsTrophic Levels A feeding step in a food chainA feeding step in a food chain First OrderFirst Order
Eats autotrophsEats autotrophs HerbivoreHerbivore ExampleExample
Second OrderSecond Order Eats first order organismsEats first order organisms CarnivoreCarnivore ExampleExample
Food WebFood Web A model that represents all the possible A model that represents all the possible
feeding relationships at each trophic level feeding relationships at each trophic level in an ecosystemin an ecosystem
More realistic because…More realistic because… Most organisms depend upon more than one Most organisms depend upon more than one
other species for foodother species for food Let’s look at an example of a food web…Let’s look at an example of a food web…
Ecological PyramidsEcological Pyramids Can show how Can show how
energy flows through energy flows through an ecosysteman ecosystem
Base represents:Base represents: Autotrophs (1Autotrophs (1stst trophic trophic
level)level)
Higher levels Higher levels represents:represents: Heterotrophs (2Heterotrophs (2ndnd, 3, 3rdrd, ,
trophic levels)trophic levels)
3 Types of Pyramids3 Types of Pyramids
Shows how much Shows how much energy is transferred energy is transferred from producers to from producers to consumersconsumers
Energy decreases Energy decreases 10% at each level10% at each level
EnergyEnergy
NumbersNumbers
Shows Shows population size population size decreases at decreases at each higher each higher trophic leveltrophic level
Not always Not always truetrue Thousands of Thousands of
insects can eat insects can eat off one treeoff one tree
BiomassBiomass
Represents the Represents the total weight of total weight of living matter at living matter at each trophic each trophic levellevel
Cycles in NatureCycles in Nature
Matter is constantly recycled.Matter is constantly recycled. It is never It is never LOSTLOST!!
The Water CycleThe Water Cycle Life on Earth depends upon Life on Earth depends upon WATERWATER How the cycle works:How the cycle works:
EvaporationEvaporation• Liquid to gas (called water vapor)Liquid to gas (called water vapor)
CondensationCondensation• Water vapor condenses on dust in air + forms cloudsWater vapor condenses on dust in air + forms clouds
PrecipitationPrecipitation• Water falls to ground in form of rain, ice, or snowWater falls to ground in form of rain, ice, or snow
TranspirationTranspiration• Loss of water by plants – puts water vapor into airLoss of water by plants – puts water vapor into air
What is looks like…What is looks like…
The Carbon CycleThe Carbon Cycle CarbonCarbon is an important part of all living things is an important part of all living things
Makes up all molecules of life – Makes up all molecules of life – • carbohydrates, proteins, fats, nucleic acidscarbohydrates, proteins, fats, nucleic acids
Parts of Carbon Cycle:Parts of Carbon Cycle: PhotosynthesisPhotosynthesis
• Autotrophs use COAutotrophs use CO22 from air to make energy-rich compounds from air to make energy-rich compounds RespirationRespiration
• Both autotrophs + heterotrophs use COBoth autotrophs + heterotrophs use CO22 in processes and in processes and release COrelease CO22 back into the evironment back into the evironment
Other ways:Other ways:• Death + decayDeath + decay• Burning of fossil fuelsBurning of fossil fuels• FiresFires
What it looks like…What it looks like…
The Nitrogen CycleThe Nitrogen Cycle Atmospheric NitrogenAtmospheric Nitrogen
Nitrogen makes up 78% of atmosphereNitrogen makes up 78% of atmosphere
Nitrogen-fixing bacteriaNitrogen-fixing bacteria Bacteria found on roots of plants fix nitrogen into Bacteria found on roots of plants fix nitrogen into
different compounds in the soildifferent compounds in the soil
Animal consumptionAnimal consumption Eat plants or other animalsEat plants or other animals Waste materials enter groundWaste materials enter ground Decomposers – put Nitrogen back into atmosphereDecomposers – put Nitrogen back into atmosphere
What it looks like…What it looks like…
The Phosphorus CycleThe Phosphorus Cycle Short termShort term
Plants get P from soilPlants get P from soil Animals eat plants – get PAnimals eat plants – get P When animals die, P gets returned to soilWhen animals die, P gets returned to soil
Long termLong term P enters waterP enters water P gets absorbed into rocksP gets absorbed into rocks Millions of years later, rocks erode, releases P Millions of years later, rocks erode, releases P
back into cycleback into cycle
What it looks like…What it looks like…