Ecosystem StructureEcosystem Structure
The Nature of EcologyThe Nature of Ecology
The study of the interrelationships between plants and animals and their physical environment
The study of the interrelationships between plants and animals and their physical environment
OrganismsOrganisms
PopulationsPopulations
CommunitiesCommunities
EcosystemsEcosystems
BiosphereBiosphere
How do Ecologists learn about natural systems?How do Ecologists learn about natural systems?
Field researchField research
Remote sensingRemote sensing
Geographic information systems (GIS)Geographic information systems (GIS)
Laboratory researchLaboratory research
Systems analysis (mathematical,computer models)
Systems analysis (mathematical,computer models)
Matter: anything that has mass and occupies spaceMatter: anything that has mass and occupies space
ElementsElements
CompoundsCompounds
MixturesMixtures
MoleculesMolecules
The States of MatterThe States of Matter
SolidSolid
LiquidLiquid
GasGas
Energy: the ability to do workEnergy: the ability to do work
Kinetic energy Kinetic energy Potential energyPotential energyHeatHeat
The Law of Conservation of MatterThe Law of Conservation of Matter
Matter cannot be created nordestroyed
Matter cannot be created nordestroyed
Matter only changes formMatter only changes form
There is no “away”There is no “away”
Laws Governing Energy ChangesLaws Governing Energy Changes
Energy is neither created nor destroyed Energy is neither created nor destroyed
Energy only changes form Energy only changes form
You can’t get something for nothing You can’t get something for nothing
First Law of Thermodynamics (Energy)First Law of Thermodynamics (Energy)
ENERGY IN = ENERGY OUTENERGY IN = ENERGY OUT
Laws Governing Energy ChangesLaws Governing Energy Changes
Second Law of ThermodynamicsSecond Law of Thermodynamics
In every transformation, some energy is converted to heat (lower quality)
In every transformation, some energy is converted to heat (lower quality)
You cannot break even in terms of energy quality
You cannot break even in terms of energy quality
Connections: Matter and Energy Laws and Environmental ProblemsConnections: Matter and Energy Laws and Environmental Problems
High-throughput (waste) economy High-throughput (waste) economy
Matter-recycling economy Matter-recycling economy
Low-throughputeconomy
Low-throughputeconomy
Ecosystem StructureEcosystem StructureEcosystem StructureEcosystem Structure
• Ecosystems have two general Ecosystems have two general categories of components:categories of components:
– BioticBiotic - living organisms - living organisms
– AbioticAbiotic - nonliving - nonliving
The Biotic Components of EcosystemsThe Biotic Components of Ecosystems
Producers(autotrophs)
Producers(autotrophs)
- Photosynthesis- Photosynthesis
Consumers(heterotrophs)
Consumers(heterotrophs)
- Aerobic respiration- Aerobic respiration
Decomposers Decomposers
ConsumersConsumers
• Primary, secondary, tertiary, etc.Primary, secondary, tertiary, etc.
• HerbivoreHerbivore - plant eater - plant eater
• CarnivoreCarnivore - meat eater - meat eater
• OmnivoreOmnivore - mixed plant/animal diet - mixed plant/animal diet
The Abiotic Components of EcosystemsThe Abiotic Components of Ecosystems
1) Outside energy source1) Outside energy source
2) Physical factors that determine2) Physical factors that determine weather, climateweather, climate
3) Chemicals essential for life3) Chemicals essential for life
Outside Energy SourceOutside Energy Source
PowersPowersphotosynthesisphotosynthesis
Warms earthWarms earth
Powers waterPowers watercyclecycle
Physical factors that determinePhysical factors that determineweather, climateweather, climatePhysical factors that determinePhysical factors that determineweather, climateweather, climate
HeatHeat
WindWind
PrecipitationPrecipitation
TopographyTopography
HeatHeatHeatHeat
LocationLocation
ReflectionReflection
RetentionRetention
Wind and PrecipitationWind and PrecipitationWind and PrecipitationWind and Precipitation• Uneven heatingUneven heating
• Ascending, Ascending, descending air descending air massesmasses
Slide 13Slide 13Slide 13Slide 13Slide 13
Moist surface warmed by sun
Flows toward low pressure,picks up moisture and heat
Warm,dry air
Hot, wetair
Falls, is compressed, warms Rises, expands, cools
Heat releasedradiates to space
LOWPRESSURE
HIGHPRESSURE
Cool, dryair
Condensationand
precipitation
HIGHPRESSURE
HIGHPRESSURE
LOWPRESSURE
LOWPRESSURE
Figure 6-10Page 117
ModifiersModifiersModifiersModifiers
• Rotation of the Rotation of the globeglobe
• Geologic Geologic featuresfeatures
Rain ShadowsRain ShadowsRain ShadowsRain Shadows
Lake-effect PrecipitationLake-effect PrecipitationLake-effect PrecipitationLake-effect Precipitation
Chemicals Essential for LifeChemicals Essential for LifeChemicals Essential for LifeChemicals Essential for Life
• Elements and Elements and compoundscompounds
• Recycled Recycled between biotic between biotic and abiotic partsand abiotic parts
Organic vs. InorganicOrganic vs. InorganicOrganic vs. InorganicOrganic vs. Inorganic
• Organic compounds made by living thingsOrganic compounds made by living things– e.g., proteins, fats, DNAe.g., proteins, fats, DNA
• Inorganic compounds produced by biotic Inorganic compounds produced by biotic or abiotic processesor abiotic processes– e.g., water, carbon dioxide
Limiting Factor PrincipleLimiting Factor PrincipleLimiting Factor PrincipleLimiting Factor Principle
• Too much or too little of any abiotic factor can Too much or too little of any abiotic factor can limit or prevent growth of a population, even if limit or prevent growth of a population, even if all other factors are optimal for that population.all other factors are optimal for that population.
• Single factor most over-abundant or deficient in Single factor most over-abundant or deficient in an ecosystem determines presence/absence of an ecosystem determines presence/absence of specific plants/animals.specific plants/animals.
Ecosystem Concepts and ComponentsEcosystem Concepts and Components
Biomes Biomes
Role of climate
Role of climate
Aquatic life zones
Aquatic life zones
Biomes - terrestrial ecosystemsBiomes - terrestrial ecosystemsBiomes - terrestrial ecosystemsBiomes - terrestrial ecosystems
Dry woodlands and shrublands (chaparral)
Temperate grassland
Temperate deciduous forest
Boreal forest (taiga), evergreen coniferousforest (e.g., montane coniferous forest)
Arctic tundra (polar grasslands)
Tropical savanna,thorn forest
Tropical scrub forest
Tropical deciduous forest
Tropical rain forest,tropical evergreen forest
Desert
Ice
Mountains(complex zonation)
Semidesert,arid grassland
Tropic ofCapricorn
Equator
Tropic ofCancer
BiomesBiomesBiomesBiomes
• Determined primarily by Determined primarily by precipitationprecipitation
– ForestsForests (> 75 cm rain per year) (> 75 cm rain per year)
– GrasslandsGrasslands (30-75 cm rain per year) (30-75 cm rain per year)
– DesertsDeserts (< 30 cm rain per year) (< 30 cm rain per year)
BiomesBiomesBiomesBiomes
• Determined secondarily by Determined secondarily by temperaturetemperature– Type of forest, grassland, or desert Type of forest, grassland, or desert
determined by average annual determined by average annual temperaturetemperature
Aquatic ecosystemsAquatic ecosystemsAquatic ecosystemsAquatic ecosystems
• Determined by salinityDetermined by salinity– MarineMarine
– EstuaryEstuary
– FreshwaterFreshwater
Type determined by: depth, nearness Type determined by: depth, nearness to shore, size, water movementto shore, size, water movement
Ecosystem FunctionEcosystem Function
One-way flowof energy
One-way flowof energy
Cycling ofmatter
Cycling ofmatter
Matter and Energy Flow in EcosystemsMatter and Energy Flow in Ecosystems
Food chainsFood chains Food websFood webs
TrophicTrophiclevelslevels
Producer to primaryconsumer
Primaryto secondaryconsumer
Secondary tohigher-levelconsumer
All producers andconsumers todecomposers
Fungi
Gambel'squail
Red-tailed hawk
Collaredlizard
Jackrabbit
Yucca
Kangaroo ratKangaroo rat
AgaveAgave
RoadrunnerRoadrunner
Diamondback rattlesnakeDiamondback rattlesnakeDarklingbeetleDarklingbeetle
BacteriaBacteria
Pricklypearcactus
Pricklypearcactus
Ecological PyramidsEcological Pyramids
Pyramid ofenergy flow
Pyramid ofenergy flow
Ecologicalefficiency (10%)
Ecologicalefficiency (10%)
Pyramid ofbiomass
Pyramid ofbiomass
Pyramid ofnumbers
Pyramid ofnumbers
Energy Productivity of EcosystemsEnergy Productivity of Ecosystems
Primary productivityPrimary productivity
Secondary productivitySecondary productivity
Energy stored/area/timeEnergy stored/area/time
Matter Cycling in EcosystemsMatter Cycling in Ecosystems
-Biogeochemical or nutrient cycles-Biogeochemical or nutrient cycles
-Hydrologic cycle (H2O)-Hydrologic cycle (H2O)
-Atmospheric or gaseous cycles (C, N)-Atmospheric or gaseous cycles (C, N)
-Sedimentary cycles (P, S)-Sedimentary cycles (P, S)
Hydrologic (Water) CycleHydrologic (Water) Cycle
Driven by physical forcesDriven by physical forces
The Carbon CycleThe Carbon Cycle
Driven by biological forces:Driven by biological forces:photosynthesis and respirationphotosynthesis and respiration
The Nitrogen CycleThe Nitrogen Cycle
Driven by biological forces: bacteriaDriven by biological forces: bacteria
Root nodulesRoot noduleson legumeson legumes
CyanobacteriaCyanobacteria
The Phosphorus CycleThe Phosphorus Cycle
Driven by physical forcesDriven by physical forces
Community ChangeCommunity Change
Ecological succession - gradualreplacement of one kind of communityof organisms by another over time
Ecological succession - gradualreplacement of one kind of communityof organisms by another over time
-Initiated by disturbance-Initiated by disturbance
Ecological Succession: Communities in Transition - Type #1Ecological Succession: Communities in Transition - Type #1
Primary successionPrimary succession
- begins with barren area, no soil- begins with barren area, no soil
Ecological Succession: Communities in Transition - Type #1Ecological Succession: Communities in Transition - Type #1
Slow soil development by weathering,activities of tolerant species
Slow soil development by weathering,activities of tolerant species- pioneer species- pioneer species
Ecological Succession: Communities in Transition - Type #1Ecological Succession: Communities in Transition - Type #1
Gradual changeover to less tolerantspecies over long periods of time
Gradual changeover to less tolerantspecies over long periods of time
- equilibrium or successional species- equilibrium or successional species
Primary SuccessionPrimary Succession
Ecological Succession: Communities in Transition - Type #2Ecological Succession: Communities in Transition - Type #2
Secondary successionSecondary succession
- begins with soil already in place- begins with soil already in place
Ecological Succession: Communities in Transition - Type #2Ecological Succession: Communities in Transition - Type #2
Rapid changeover to less tolerantspecies over shorter periods of time
Rapid changeover to less tolerantspecies over shorter periods of time- rapid because soil already present- rapid because soil already present
Secondary SuccessionSecondary Succession
Succession and WildlifeSuccession and Wildlife
The End ProductThe End Product
If undisturbed, communities changetoward a relatively stable stage
If undisturbed, communities changetoward a relatively stable stage
- climax community- climax community
- long-term presence if not disturbed- dominated by less-tolerant species- general equilibrium
- long-term presence if not disturbed- dominated by less-tolerant species- general equilibrium
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