Ecosystems: Components, Energy Flow, and Matter Cycling

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Ecosystems Components, Energy Flow, and Matter
Cycling

• All things come from earth, and to earth they
  all returnMenander

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Ecology and the levels of organization of matter

• EcologyGreek oikos meaning house
• Study of how organisms interact with one another
  and their non-living environment (biotic and
  abiotic components)
• Studies connections in nature on the thin life
  supporting membrane of air, water, and soil
• Levels of Organization of Matter
• Subatomic to biosphere

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Ecosystem Organization

• Organisms
• Made of cells
• Eukaryotic vs Prokaryotic
• Species
• Groups of organisms that resemble one another in
  appearance, behavior, and genetic make up
• Sexual vs Asexual reproduction
• Production of viable offspring in nature
• 1.5 million named 10-14 million likely
• Populations
• Genetic diversity
• Communities
• Ecosystems
• Biosphere

Fig. 4.2, p. 66
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Earths Life Support Systems

• Troposphere
• To 11 miles
• Air is here
• Stratosphere
• 11 to 30 miles
• Ozone layer
• Hydrosphere
• Solid, liquid, and gaseous water
• Lithosphere
• Crust and upper mantle
• Contains non-renewable res.

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Sustaining Life on Earth

• One way flow of high quality energy
• The cycling of matter (the earth is a closed
  system)
• Gravity
• Causes downward movement of matter

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Major Ecosystem Components

• Abiotic Components
• Water, air, temperature, soil, light levels,
  precipitation, salinity
• Sets tolerance limits for populations and
  communities
• Some are limiting factors that structure the
  abundance of populations

• Biotic Components
• Producers, consumers, decomposers
• Plants, animals, bacteria/fungi
• Biotic interactions with biotic components
  include predation, competition, symbiosis,
  parasitism, commensalism etc.

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Limiting Factors on Land in H2O

• Terrestrial
• Sunlight
• Temperature
• Precipitation
• Soil nutrients
• Fire frequency
• Wind
• Latitude
• Altitude

• Aquatic/Marine
• Light penetration
• Water clarity
• Water currents
• Dissolved nutrient concentrations
• Esp. N, P, Fe
• Dissolved Oxygen concentration
• Salinity

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The Source of High Quality Energy

• Energy of sun lights and warms the planet
• Supports PSN
• Powers the cycling of matter
• Drives climate and weather that distribute heat
  and H2O

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Fate of Solar Energy

• Earth gets 1/billionth of suns output of energy
• 34 is reflected away by atmosphere
• 66 is absorbed by chemicals in atmosphere
  re-radiated into space
• Visible light, Infrared radiation (heat), and a
  small amount of UV not absorbed by ozone reaches
  the atmosphere
• Energy warms troposphere and land
• Evaporates water and cycles it along with gravity
• Generates winds
• A tiny fraction is captured by photosynthesizing
  organisms
• Natural greenhouse effect vs. Global Warming

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Primary Productivity

• The conversion of light energy to chemical energy
  is called gross primary production.
• Plants use the energy captured in photosynthesis
  for maintenance and growth.
• The energy that is accumulated in plant biomass
  is called net primary production.

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• To sustain life on _____ of energy and ____ of
  matter.
• A.) one way flow, cycling
• B.) one way flow, one way flow
• C.) cycling, cycling
• D.) cycling, one way flow
• E.) nothing

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• The layer containing ozone is called
• A.) troposphere
• B.) lithosphere
• C.) stratosphere
• D.) hydrosphere
• E.) mesosphere

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• Ecology is the study of how _____ interact
• A.) communities
• B.) organisms
• C.) ecosystems
• D.) people
• E.) animals

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Primary Productivity

• NPPGPP-respiration rate
• GPP RATE at which producers convert solar energy
  into chemical energy as biomass
• Rate at which producers use photosynthesis to fix
  inorganic carbon into the organic carbon of their
  tissues
• These producers must use some of the total
  biomass they produce for their own respiration
• NPP Rate at which energy for use by consumers is
  stored in new biomass (available to consumers)
• Units Kcal/m2/yr or g/m2/yr
• How do you measure it? AP Lab Site
• Most productive vs. least productive

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What are the most productive Ecosystems?
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Fate of Primary Productivity and Some important
questions

• Since producers are ultimate source of all food,
  why shouldnt we just harvest the plants of the
  worlds marshes?
• Why dont we clear cut tropical rainforests to
  grow crops for humans?
• Why not harvest primary producers of the worlds
  vast oceans?
• Vitousek et al Humans now use, waste, or
  destroy about 27 of earths total potential NPP
  and 40 of the NPP of the planets terrestrial
  ecosystems

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Biotic Components of Ecosystems

• Producers (autotrophs)
• Source of all food
• Photosynthesis
• Consumersheterotroph
• Aerobic respiration
• Anaerobic respiration
• Methane, H2S
• Decomposers
• Matter recyclers
• Release organic compounds into soil and water
  where they can be used by producers

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Trophic Levels

• Each organism in an ecosystem is assigned to a
  feeding (or Trophic) level
• Primary Producers
• Primary Consumers (herbivores)
• Secondary Consumer (carnivores)
• Tertiary Consumers
• Omnivores
• Detritus feeders and scavengers
• Directly consume tiny fragments of dead stuff
• Decomposers
• Digest complex organic chemicals into inorganic
  nutrients that are used by producers
• Complete the cycle of matter

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Detritivores vs Decomposers stop
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Energy Flow and Matter Cycling in Ecosystems

• Food Chains vs. Food Webs
• KEY There is little if no matter waste in
  natural ecosystems!

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Generalized Food Web of the Antarctic
Note Arrows Go in direction Of energy flow
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Food Webs and the Laws of matter and energy

• Food chains/webs show how matter and energy move
  from one organism to another through an ecosystem
• Each trophic level contains a certain amount of
  biomass (dry weight of all organic matter)
• Chemical energy stored in biomass is transferred
  from one trophic level to the next
• With each trophic transfer, some usable energy is
  degraded and lost to the environment as low
  quality heat
• Thus, only a small portion of what is eaten and
  digested is actually converted into an organisms
  bodily material or biomass (WHAT LAW ACCOUNTS FOR
  THIS?)

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Food Webs and the Laws of matter and energy

• Food chains/webs show how matter and energy move
  from one organism to another through an ecosystem
• Each trophic level contains a certain amount of
  biomass (dry weight of all organic matter)
• Chemical energy stored in biomass is transferred
  from one trophic level to the next
• With each trophic transfer, some usable energy is
  degraded and lost to the environment as low
  quality heat
• Thus, only a small portion of what is eaten and
  digested is actually converted into an organisms
  bodily material or biomass (WHAT LAW ACCOUNTS FOR
  THIS?)
• Ecological Efficiency
• The of usable nrg transferred as biomass from
  one trophic level to the next (ranges from 5-20
  in most ecosystems, use 10 as a rule of thumb)
• Thus, the more trophic levels or steps in a food
  chain, the greater the cumulative loss of useable
  energy

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Food Webs and the Laws of matter and energy

• Ecological Efficiency
• The of usable energy transferred as biomass
  from one trophic level to the next (ranges from
  5-20 in most ecosystems, use 10 as a rule of
  thumb)
• Thus, the more trophic levels or steps in a food
  chain, the greater the cumulative loss of useable
  energy

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Pyramids of Energy and Matter

• Pyramid of Energy Flow
• Pyramid of Biomass

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• Which of the following is the most productive
  ecosystem per meter squared?
• A.) desert
• B.) open ocean
• C.) estuaries
• D.) tundra
• E.) rainforest

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• Which of the following is the most productive
  ecosystem?
• A.) desert
• B.) open ocean
• C.) estuaries
• D.) tundra
• E.) rainforest

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• What is the usual percentage of ecological
  efficiency?
• A.) 2
• B.) 20
• C.) 15
• D.) 10
• E.)30

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• Which trophic level makes its own food from
  sunlight?
• A.) primary producers
• B.) primary consumers
• C.) secondary consumers
• D.) tertiary consumers
• E.) decomposers

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Ecological Pyramids of Energy
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Ecological Pyramids of Biomass
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Implications of Pyramids.

• Why could the earth support more people if the
  eat at lower trophic levels?
• Why are food chains and webs rarely more than
  four or five trophic levels?
• Why do marine food webs have greater ecological
  efficiency and therefore more trophic levels than
  terrestrial ones?
• Why are there so few top level carnivores?
• Why are these species usually the first to suffer
  when the the ecosystems that support them are
  disrupted?

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Ecosystem Services and Sustainability
Lessons From Nature!

1. Use Renewable Solar Energy As Energy Source
2. Recycle the chemical nutrients needed for life

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Matter Cycles

• You are responsible for knowing the water,
  carbon, nitrogen, sulfur, and phosphorus cycles
• Know major sources and sinks
• Know major flows
• Know how human activities are disrupting these
  cycles

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Carbon Cycle
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Nitrogen Cycle
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Zonation in Lakes
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Thermal Stratification in Lakes
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____ is the absorption of nitrogen into plants
through the soil. A.) nitrogen fixation B.)
assimilation C.) nitrification D.)
denitrification E.) ammonification
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Which of the following processes produce a
product that is toxic to the plants? A.)
nitrogen fixation B.) assimilation C.)
nitrification D.) denitrification E.)
ammonification
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Which of the following processes makes the
nitrogen product usable by the plant? A.)
nitrogen fixation B.) assimilation C.)
nitrification D.) denitrification E.)
ammonification
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Which trophic level has the highest amount of
biomass? A.) tertiary consumers B.)
zooplankton C.)
phytoplankton D.) primary producers E.)
primary consumers
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What is the deepest zone in a lake? A.) benthic
zone B.) bathayal zone C.) abyssal zone
D.) euphotic zone E.) limnetic zone
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Soils Formation

• Soil horizons

• Soil profile

• Humus

Fig. 10.12, p. 220
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Soil Properties

• Infiltration

• Leaching

• Porosity/permeability

• Texture

• Structure

• pH

Fig. 10.16, p. 224
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Soil Quality
Texture Nutrient Infiltration Water-Holding Aerati
on Tilth Capacity Capacity Clay Good Poor Good
Poor Poor Silt Medium Medium Medium Medium Medium
Sand Poor Good Poor Good Good Loam
Medium Medium Medium Medium Medium
Fig. 10.15b, p. 223
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Soil Chemistry

• Acidity / Alkalinity pH
• Major Nutrients
• Nitrogen
• Phosphorus (phosphates)
• Potassium (potash)

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Acidity / Alkalinity pH

• Proper pH directly affects the availability of
  plant food nutrients
• Soil is best if between pH 6 8 (except for
  certain acid loving plants)
• Sour if too acidic
• Sweet if too basic

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Acidity / Alkalinity pH

• Too acidic or basic will not
• Allow compounds to dissolve
• Allow presence of certain ions
• If soil is too acidic, add ground limestone
• If soil is too basic, add organic material like
  steer manure

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Nitrogen Content

• Importance
• Stimulates above ground growth
• Produces rich green color
• Influences quality and protein content of fruit
• A plants use of other elements is stimulated by
  presence of N
• Taken up by plant as NH4 and NO3-
• Replenished naturally by rhizobacteria on legume
  roots
• Fertilizer from manure or Chemical rxn.

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Phosphorus for Growth

• Abundant in
• Strong root system
• Increases seed yield and fruit development
• Parts of root involved in water uptake (hair)
• Major role in transfer of energy
• Taken up by plant as H2PO4- and HPO4-2
• Fertilizer is made from rock phosphate

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Potassium Content

• Potash
• Important in vigor and vitality of plant
• Carries carbohydrates through the plant
• Improves color of flowers
• Improves quality of fruit
• Promotes vigorous root systems
• Offsets too much N
• Found naturally in feldspar and micas

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Justus von Liebigs Law of Minimum

• Plant production can be no greater than that
  level allowed by the growth factor present in the
  lowest amount relative to the optimum amount for
  that factor

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Soil Formation

• Soils develop in response to
• Climate
• Living organisms
• Parent Material
• Topography
• Time

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Climate

• Two most important factors that determine climate
  are Temperature and Moisture and they affect
• Weathering processes
• Microenvironmental conditions for soil organisms
• Plant growth
• Decomposition rates
• Soil pH
• Chemical reactions in the soil

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Parent Material

• Refers to the rock and minerals from which the
  soil derives.
• The nature of the parent rock has a direct effect
  on the soil texture, chemistry and cycling
  pathways.
• Parent material may be native or transported to
  area by wind , water or glacier.

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Topography

• Physical characteristics of location where soil
  is formed.
• Drainage
• Slope direction
• Elevation
• Wind exposure
• Viewed on Macro-scale (valley) or microscale
  (soil type in field)

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Time

• After enough time, the soil may reach maturity.
• Depends on previous factors
• Feedback of biotic and abiotic factors may
  preserve or erode mature profile.

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Destructional -WeatheringLandscapes broken down
by chemical physical processes erosion

• Physical
• includes temperature changes (freezing and
  thawing, thermal expansion), crystal growth,
  pressure, plant roots, burrowing animals
• causes disintegration of parent material and
  facilitates chemical weathering

• Chemical
• always in water
• includes hydration, hydrolysis, oxidation,
  reduction, carbonation and exchange
• examples
• oxidation of Fe to form limonite, deposited in
  joints, inhibits groundwater flow
• hydrolysis of feldspars to form clay (kaolin) -
  forms infill for joints

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Destructional - Mass wasting

• Gravitational movement of weathered rock down
  slope without aid of water or wind (landslips)
• transported material is called colluvium
• often set off by mans activity
• can involve very small to immense volumes of
  material
• sliding, toppling, unravelling, slumping
• controlled by discontinuities (joints, bedding,
  schistocity, faults etc)

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Destructional - Erosionmost significantly by
running water

• Sheet erosion
• by water flowing down valley sides
• severe when vegetation removed and geological
  materials uncemented
• Stream erosion
• materials brought downslope by mass wasting and
  sheet erosion are transported by streams
• erosion by the streams - meanders etc

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Destructional - Karsts

• Forms by dissolution of limestone - limestone is
  only common rock soluble in water - dissolved
  carbon dioxide in rain water
• form highly variable ground conditions
• formation of sink holes - when buried leads to
  surface subsidence

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• O Horizon
• A. affected by weathering
• B. bedrock
• C. "subsoil", and consists of mineral layers
• D. surface layer
• E. top layer of the soil horizons

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• A Horizon
• A. affected by weathering
• B. bedrock
• C. "subsoil", and consists of mineral layers
• D. surface layer
• E. top layer of the soil horizons

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• B Horizon
• A. affected by weathering
• B. bedrock
• C. "subsoil", and consists of mineral layers
• D. surface layer
• E. top layer of the soil horizons

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• C Horizon
• A. affected by weathering
• B. bedrock
• C. "subsoil", and consists of mineral layers
• D. surface layer
• E. top layer of the soil horizons

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• R Horizon
• A. affected by weathering
• B. bedrock
• C. "subsoil", and consists of mineral layers
• D. surface layer
• E. top layer of the soil horizons