Ecosystems: Components, Energy Flow, and Matter Cycling

1
Ecosystems Components, Energy Flow, and Matter
Cycling

• Ch. 4 APES Notes
• Mrs. Sealy

2
Organisms and Species 

• Ecology study of connections in nature. 
• 1. cell basic unit of life in organisms.
• a. prokaryotic  no organelles, no membrane
  bound nucleus
• b. eukaryotic nucleus contained in a
  membrane
•  

3
Organism any form of life. 

• species groups of organisms that can mate and
  produce fertile offspring (5 to 100 million on
  earth). 

4
Reproduction production of offspring

• a. Sexual two different parents
• b. Asexual no mixing of genes, offspring are
  identical

5
Population members of the same species that
occupy a given area.

• Can Change
• a. size
• b. age distribution
• c.  Density
• d. genetic composition (genetic diversity)
•  
• COMMUNITY populations of all different species
  occupying a given area (plants, animals,
  decomposers, etc).
•  
• ECOSYSTEM-a community plus the nonliving factors
  that surround them (plants, animals, soil, water,
  weather, etc.)

6
Biosphere
Biosphere
Ecosystems
Communities
Populations
Organisms
Fig. 4.2, p. 72
7
II. Earths Life Support Systems

•  
• BIOSPHERE portion of earth where life exists.
•   
• ATMOSPHERE thin envelope of air surrounding the
  planet.
• 1.      troposphere inner (78 N, 21 O)
• 2.      stratosphere outer (contains ozone)
•  
• HYDROSPHERE earths water.
• a.       liquid (surface, underground)
• b.      ice (polar, icebergs, soil)
• c.       water vapor (atmosphere)
•  
• LITHOSPHERE earths land
• a.       crust (fossil fuels, minerals)
• b.      upper mantle
•  

8
Atmosphere
Vegetation and animals
Biosphere
Soil
Crust
Rock
core
Mantle
Lithosphere
Crust (soil and rock)
Crust
Biosphere (Living and dead organisms)
Atmosphere (air)
Hydrosphere (water)
Lithosphere (crust, top of upper mantle)
Fig. 4.6, p. 74
9
Factors Sustaining Life On Earth

• 1. One way flow of high quality energy
• a. Through food webs
• b. Into the environment from organisms
• c. Back into space as heat
• 2. Cycling of Matter 
• 3. Gravity

   
10
Biosphere
Carbon cycle
Phosphorus cycle
Nitrogen cycle
Water cycle
Oxygen cycle
Heat in the environment
Heat
Heat
Heat
Fig. 4.7, p. 75
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Importance of the Sun

•  
• 1. Lights and warms planet
• 2. Supports Photosynthesis (provides all food)
• 3. Powers matter cycling
• 4. Drives climate and weather systems

13
Natural Greenhouse Effect

• greenhouse gases such as water vapor, carbon
  dioxide, methane, nitrous oxide, and ozone trap
  heat in earths atmosphere.

14
Solar radiation
Energy in Energy out
Reflected by atmosphere (34)
Radiated by atmosphere as heat (66)
UV radiation
Lower Stratosphere (ozone layer)
Visible light
Greenhouse effect
Troposphere
Absorbed by ozone
Heat
Absorbed by the earth
Heat radiated by the earth
Earth
Fig. 4.8, p. 75
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III.  Ecosystem Concepts and Components

• Biomes large regions characterized by distinct
  climate and specific life forms, especially
  vegetation adapted to it (grasslands, forests,
  deserts, etc.)
• climate long term patterns of weather.

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Coastal chaparral and scrub
Desert
Coniferous forest
Coniferous forest
Prairie grassland
Deciduous forest
Appalachian Mountains
Mississippi River Valley
Great Plains
Rocky Mountains
Great American Desert
Sierra Nevada Mountain
Coastal mountain ranges
15,000 ft
10,000 ft
Average annual precipitaion
5,000 ft
100-125 cm (40-50 in.)
75-100 cm (30-40 in.)
50-75 cm (20-30 in.)
25-50 cm (10-20 in.)
below 25 cm (0-10 in.)
Fig. 4.9, p. 76
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Aquatic Life Zones biomes in water. 

• a. freshwater life zones (lakes, rivers)
• b. ocean or marine life zones (estuaries,
  coastlines, coral reefs, deep oceans)
•  

18
Terrestrial Ecosystems
Aquatic Life Zones
Sunlight Temperature Precipitation Wind
Latitude (distance from equator) Altitude
(distance above sea level) Fire frequency Soil
Light penetration Water currents Dissolved
nutrient concentrations (especially N and P)
Suspended solids
Fig. 4.13, p. 79
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Land zone
Transition zone
Aquatic zone
ecotone transitional zone between ecosystems,
contains a mixture of species from connecting
ecosystems.
Fig. 4.10, p. 77
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Components of Ecosystems

• A.     Biotic living parts of ecosystems
  (plants, animals, and microorganisms) biota.
•  
• 1. Producers or Autotrophs (photosynthesis and
  chemosynthesis)
• 2. Consumers or Heterotrophs
•  
• a.  Herbivores
• b.  Carnivores (secondary or tertiary
  consumers)
• c.  Omnivores
• d.  Scavengers

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e. detritovores feed on dead organisms or
waste. f. Detritus feeders extract nutrients
from partly decomposed organic mater in leaf
litter, plant debris, and animal dung. (crabs,
termites, earthworms) G decomposers recycle
organic matter in ecosystems (bacteria and
fungi)
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Detritus feeders
Decomposers
Bark beetle engraving
Carpenter ant galleries
Termite and carpenter ant work
Long-horned beetle holes
Dry rot fungus
Wood reduced to powder
Mushroom
Powder broken down by decomposers into plant
nutrients in soil
Time progression
Fig. 4.15, p. 81
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Sun
Producers (rooted plants)
Producers (phytoplankton)
Primary consumers (zooplankton)
Secondary consumer (fish)
Dissolved chemicals
Tertiary consumer (turtle)
Sediment
Decomposers (bacteria and fungi)
Fig. 4.11, p. 78
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Sun
Oxygen (O2)
Producer
Carbon dioxide (rabbit)
Secondary consumer (fox)
Primary consumer (rabbit)
Producers
Falling leaves and twigs
Precipitation
Soil decomposers
Water
Soluble mineral nutrients
Fig. 4.12, p. 78
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9/quickflicks/
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3.      Important Biotic Processes

•  
• a.     Aerobic Respiration removes oxygen from
  the environment and adds carbon dioxide and
  water.
• b.      Anaerobic Respiration can add methane
  gas, ethyl alcohol, acetic acid, and hydrogen
  sulfide to the environment.
• c.      Photosynthesis removes carbon dioxide
  and water from the environment and adds oxygen
  and water.
•  
•  

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4.    Abiotic nonliving parts of ecosystems
(water, air, nutrients, solar energy)

• A.   Range of Tolerance range of physical and
  chemical environments in which a species can
  survive. 
• a.  Law of Tolerance the abundance of organisms
  is determined by whether physical and chemical
  factors fall within the range of tolerance
• b. Tolerance Limits limits for conditions beyond
  which no organisms can survive
•  

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Fig. 4.14, p. 79
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Limiting Factor abiotic factors that can
limit or prevent the growth of a population. 

•       a.       Limiting Factor Principle too
  much or too little of any abiotic factor can
  limit or prevent the growth of a population.
•  
• Ex. Desert plants (water), Corn (phosphorus).
• Ex. Aquatic Ecosystems (temp, light, dissolved
  oxygen, nutrient availability, salinity)
•  

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Biodiversity

• -the different life forms and life sustaining
  processes that can survive the variety of
  conditions currently found on earth. Gives food,
  wood, fibers, energy, raw materials, industrial
  chemicals, and medicines. Provides free
  recycling, purification, natural pest control.
• 1.      Genetic diversity variety of genes
• 2.      Species diversity variety of animals
• 3.      Ecological diversity variety of
  ecosystem
• 4.      Functional diversity variety of niches

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IV. Food Webs and Energy Flow In Ecosystems 

• Food chain- order of feeding levels in an
  ecosystem (plantgtgtcowgtgthumangtgtdecomposer),
  determines how energy and nutrients move from one
  organism to another in an ecosystem.
• Food Web - interconnected food chains, more
  realistic since consumers generally feed on more
  than one type of organism in an ecosystem.
• Trophic Levels - feeding levels.
• A.     first trophic level producers
• B.     second trophic level herbivores
• C.     third trophic level carnivores,
  omnivores, scavengers (secondary consumers)
• D.    fourth trophic level carnivores,
  omnivores, scavengers (tertiary consumers)
•  

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Abiotic chemicals (carbon dioxide, oxygen,
nitrogen, minerals)
Solar energy
Producers (plants)
Decomposers (bacteria, fungus)
Consumers (herbivores, carnivores)
Fig. 4.16, p. 82
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First Trophic Level
Second Trophic Level
Third Trophic Level
Fourth Trophic Level
Producers (plants)
Primary consumers (herbivores)
Tertiary consumers (top carnivores)
Secondary consumers (carnivores)
Heat
Heat
Heat
Heat
Solar energy
Heat
Heat
Heat
Detritvores (decomposers and detritus feeders)
Fig. 4.18, p. 83
33
Humans
Blue whale
Sperm whale
Killer whale
Elephant seal
Crabeater seal
Leopard seal
Emperor penguin
Adélie penguins
Petrel
Squid
Fish
Carnivorous plankton
Herbivorous zooplankton
Krill
Fig. 4.19, p. 84
Phytoplankton
34
Pyramids of Energy Flow

•  
• Biomass the dry weight of all organic matter
  contained in organisms.
•  
• Ecological Efficiency the percentage of useable
  energy transferred as biomass from one trophic
  level to the next.
•  
• Second Law of Thermodynamics (10 Law) only
  about 10 of useable energy is transferred as
  biomass from on trophic level to the next. The
  rest is lost to the environment as low quality
  heat.
•  
• Pyramid of Energy Flow - explain why earth can
  support more people if they eat at lower trophic
  levels (assume 90 energy loss with each transfer
  from one trophic level to the next) figure 4-20

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Tertiary consumers (human)
Decomposers
10
Secondary consumers (perch)
100
Primary consumers (zooplankton)
1,000
10,000 Usable energy Available at Each tropic
level (in kilocalories)
Producers (phytoplankton)
Fig. 4.20, p. 85
36

• Pyramid of Biomass represents the storage of
  biomass at various trophic levels in an
  ecosystem. figure 4-22

37
Abandoned Field
Ocean
Fig. 4.22, p. 86
38

• Pyramid of Numbers represents the estimated
  numbers of organisms at each trophic level..
  figure 4-23

39
Grassland (summer)
Temperate Forest (summer)
Fig. 4.23, p. 86
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Primary Productivity of Ecosystems

•  
• Gross primary productivity the rate at which an
  ecosystems producers convert solar energy into
  chemical energy as biomass in an ecosystem.
•  
• High GPP Low GPP
• Shallow waters near Open ocean
  continents Deserts
• Forests Polar regions
• Coral reef 

41

• Net Primary Prodcutivity what is left of GPP
  after it is used by an ecosystems producers to
  stay alive, grow and reproduce. This is the
  energy or biomass available to consumers in an
  ecosystem.
•  
• High NPP Low NPP
• estuaries Open ocean
• Swamps and marshes Tundra
• Tropical rain forests Desert 

42
Fig. 4.24, p. 87
43
Net Primary Productivity

• The earths net primary productivity is the upper
  limit determining the planets carrying capacity
  for all consumer species.
•  Our Share of Earths NPP
• 1)  We use, waste or destroy about 27 of earths
  NPP
• 2)  We use, waste or destroy about 40 of the
  NPP of terrestrial ecosystems

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Estuaries
Swamps and marshes
Tropical rain forest
Temperate forest
Northern coniferous forest (taiga)
Savanna
Agricultural land
Woodland and shrubland
Temperate grassland
Lakes and streams
Continental shelf
Open ocean
Tundra (arctic and alpine)
Desert scrub
Extreme desert
800
1,600
2,400
3,200
4,000
4,800
5,600
6,400
7,200
8,000
8,800
9,600
Average net primary productivity (kcal/m2/yr)
Fig. 4.25, p. 88
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63 Not used by Humans
3 Used Directly
16 Altered by Human Activity
8 Lost or Degrades Land
Fig. 4.26, p. 88
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VI. Matter Cycling in Ecosystems

•  
• A nutrient is any atom, ion, that an organism
  needs to live, grow, or reproduce.
• 1.      Water
• 2.      Carbon
• 3.      Nitrogen
• 4.      Phosphorus
• 5.      Sulfur
• 6.      Calcium

47

• Biogeochemical Cycles nutrients we need are
  cycles continuously from the nonliving
  environment (air, water, soil, rock) to living
  organisms and then back again.
• 1. Hydrologic most of the nutrient exists as
  water in some form (water cycle).
• 2. Atmospheric most of the nutrient exists in
  gaseous form in the atmosphere (Nitrogen and
  carbon cycles)
• 3. Sedimentary nutrients that do not have a
  gaseous phase, or its gaseous compounds do not
  make up a significant portion of its supply
  (phosphorus and sulfur cycles).
•  

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Water Cycle

•  
•  
• Absolute Humidity amount of water vapor found
  in a certain mass in air (g/kg)
•  
• Relative Humidity amount of water air can hold
  at a given temperature (), colder air can hold
  less water.
•  
• Condensation Nuclei tiny particles on which
  water droplets can collect.
•  
• Dew Point temperature at which condensation
  occurs

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Condensation
Rain clouds
Transpiration from plants
Transpiration
Precipitation
Precipitation
Evaporation
Precipitation to ocean
Evaporation From ocean
Infiltration and Percolation
Surface runoff (rapid)
Groundwater movement (slow)
Ocean storage
Groundwater movement (slow)
Fig. 4.28, p. 90
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Human Activities and the Hydrologic Cycle

• 1.      Over-consumption of surface and
  groundwater lead to groundwater depletion and
  saltwater intrusion into groundwater supplies.
• 2.      Clearing vegetation from land leads to
  increased runoff, decreased infiltration to
  replenish groundwater, increases risk of floods,
  and accelerates soil erosion and landslides.
• 3.      Adding nutrients and pollutants to water
  diminishes the ability of humans and other
  species to use it and interferes with natural
  purification. 

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Carbon Cycle (atmospheric cycle)  
diffusion between atmosphere and ocean
combustion of fossil fuels
Carbon dioxide dissolved in ocean water
photosynthesis
aerobic respiration
Marine food webs producers, consumers,
decomposers, detritivores
uplifting over geologic time
incorporation into sediments
death, sedimentation
sedimentation
Marine sediments, including formations with
fossil fuels
Fig. 4.29a, p. 92
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Atmosphere (mainly carbon dioxide)
volcanic action
combustion of wood (for clearing land or for fuel
photosynthesis
aerobic respiration
Terrestrial rocks
sedimentation
weathering
Land food webs producers, consumers, decomposers,
detritivores
Soil water (dissolved carbon)
Peat, fossil fuels
death, burial, compaction over geologic time
leaching runoff
Fig. 4.29b, p. 93
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Human impacts on the Carbon Cycle

• 1.      Clearing trees and other plants that
  absorb carbon dioxide by photosynthesis
• 2.      Adding large amounts of carbon dioxide to
  the atmosphere by burning fossil fuels and wood.
•  

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GASEOUS NITROGEN (N2) IN ATMOSPHERE
NITROGEN FIXATION by industry for agriculture
FOOD WEBS ON LAND
uptake by autotrophs
excretion, death, decomposition
uptake by autotrophs
FERTILIZERS
NO3- IN SOIL
NITROGEN FIXATION bacteria convert to ammonia
(NH3) this dissolves to form ammonium (NH4)
NITROGENOUS WASTES, REMAINS IN SOIL
DENTRIFICATION by bacteria
2. NITRIFICATION bacteria convert NO2- to nitrate
(NO3-)
AMMONIFICATION bacteria, fungi convert the
residues to NH3 , this dissolves to form NH4
NH3, NH4 IN SOIL
1. NITRIFICATION bacteria convert NH4 to nitrate
(NO2-)
NO2- IN SOIL
loss by leaching
loss by leaching
   Nitrogen Cycle (atmospheric cycle)
Fig. 4.30, p. 94
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Nitrogen Cycle (atmospheric cycle)

•  
• Nitrogen Fixation conversion of atmospheric
  nitrogen to ammonia that can be used by plants ( 
• a.       Cyanobacteria in soil and water
• b.      rhizobium bacteria in the nodules
  (swellings) of the roots in leguminous plants.
•  
• Nitrification conversion of ammonia in soil to
  nitrite ions then to nitrate ions that are easily
  used by plants (aerobic bacteria)
•  
• Assimilation absorption of ammonia, ammonium
  ions, and nitrate ions into plant roots from soil
  and water.
•  
• Ammonification conversion of nitrogen rich
  organic compounds from organisms into ammonia and
  ammonium ions. 
• Denitrification conversion of ammonia and
  ammonium ions to nitrate and nitrite ions and
  then back into nitrogen gas and nitrous oxide gas.

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Human Impact on the Nitrogen Cycle

• 1)      Adding Nitric Oxide gas to the atmosphere
  when we burn fuel gtgt Acid Precipitation
•  
• 2)      Adding Nitrous Oxide Gas to the
  atmosphere through anaerobic bacterias action on
  livestock waste and commercial waste leads to
  ozone depletion and the greenhouse effect.
•  
• 3)      Removing nitrogen from earths crust and
  soil through mining activities
•  
• 4)      Removing nitrogen from topsoil
• a.       harvesting nitrogen rich crops
• b.      irrigating crops
• c.       burning or clearing grasslands and
  forests before planting crops
•  
• 5)      Adding nitrogen to aquatic ecosystems
  depletes dissolved oxygen killing some aerobic
  aquatic organisms
• a.       agricultural runoff
• b.      municipal sewage
•  
• 6)      Accelerating deposition of acidic
  nitrogen compounds from the atmosphere onto
  terrestrial ecosystems.
• a.       stimulates growth of weedy plant species
• b.      crowd out species that cannot assimilate
  nitrogen as efficiently 

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FERTILIZER
GUANO
agriculture
weathering
uptake by autotrophs
uptake by autotrophs
weathering
LAND FOOD WEBS
DISSOLVED IN OCEAN WATER
MARINE FOOD WEBS
DISSOLVED IN SOILWATER, LAKES, RIVERS
death, decomposition
death, decomposition
settling out
leaching, runoff
sedimentation
ROCKS
MARINE SEDIMENTS
Fig. 4.32, p. 96
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Phosphorus Cycle (sedimentary cycle)

•  
• Human impacts on the Phosphorus Cycle 
• 1. Mining large quantities of phosphate rock for
  use as
• a.   inorganic fertilizers
• b..  detergents
•  
• 2. Reducing available phosphate in tropical
  forests through slash and burn agriculture.
• a.  phosphate is washed away by heavy rains.
•  
• 3.  Adding excess phosphate to aquatic ecosystems
  depletes dissolved oxygen and disrupts aquatic
  ecosystems
• a.   runoff from animal wastes
• b.   runoff of commercial inorganic fertilizers
  from cropland
• c.   discharge of municipal sewage
•  

59
Hydrogen sulfide (H2S)
Oxygen (O2)
Atmosphere
Sulfur dioxide (SO2) and Sulfur trioxide (SO3)

• Sulfur Cycle
• (atmospheric cycle) (figure 4-33)

Water (H2O)
Dimethl (DMS)
Industries
Sulfuric acid (H2SO4)
Volcanoes and hot springs
Ammonia (NH2)
Oceans
Fog and precipitation (rain, snow)
Ammonium sulfate (NH4)2SO4
Animals
Plants
Sulfate salts (SO42-)
Aerobic conditions in soil and water
Decaying organisms
Sulfur (S)
Anaerobic conditions in soil and water
Fig. 4.33, p. 97
Hydrogen sulfide (H2S)
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Sulfur Cycle (atmospheric cycle) (figure 4-33)

•  
• Human Impacts on the Sulfur Cycle
•  
• 1. Burning sulfur containing coal and oil to
  produce electric power
• a.  produces sulfur dioxidegtgtacid rain
•  
• 2.  refining petroleumgtgtsulfur dioxidegtgtacid rain
•  
• 3.  smelting to convert sulfur compounds of
  metallic minerals into free metals such as
  copper, lead and zinc.
• a.  produces sulfur dioxide and trioxidegtgtacid
  rain

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VII.  Ecologists Methods of Ecosystem Study

•  
• Field Research getting into nature to observe
  and measure the structure of ecosystems and what
  happens in them. Most of what we know about
  ecosystems come from field research.

62
Technology of Field Research

•  
• 1.      Remote Sensing from aircraft and
  satellites (reflected light, infrared radiation,
  microwave energy)
• 2.      Geographic Information Systems (GISs)
  information gathered from broad geographic
  regions is stored in spatial databases. Then
  computers analyze and manipulate data to produce
  computerized maps of
• a.       forest cover and health
• b.      Water resources
• c.       air pollution emissions
• d.      coastal changes
• e.       relationships between cancer and other
  health effects and pollution
• f.        changes in global sea temperature
• g.       map topography of ocean floor

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Critical nesting site locations
USDA Forrest Service
USDA Forest Service
Private owner 1
Private owner 2
Topography
Habitat type
Forest
Lake
Wetland
Grassland
Real world
Fig. 4.34, p. 98
64
Define objectives
Systems Measurement
Identify and inventory variables
Obtain baseline data on variables
Make statistical analysis of relationships among
variables
Data Analysis
Determine significant interactions
System Modeling
Construct mathematical model describing
interactions among variables
System Simulation
Run the model on a computer, with values entered
for different variables
System Optimization
Evaluate best ways to achieve objectives
Fig. 4.35, p. 98
65

• System Analysis used to set up observe and make
  measurements of model ecosystems and populations
  under laboratory conditions. Quicker and cheaper
  than similar experiments in the field. Must be
  supported by field research due to unknown
  complexity of natural ecosystems.

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Solar Capital
Air resources and purification
Climate control
Recycling vital chemicals
Water resources and purification
Renewable energy resources
Soil formation and renewal
Natural Capital
Nonrenewable energy resources
Waste removal and detoxification
Nonrenewable mineral resources
Natural pest and disease control
Potentially renewable matter resources
Biodiversity and gene pool
Fig. 4.36, p. 99