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Unit 9: EcologyUnit 9: Ecology
Chapters 50 – 55Chapters 50 – 55
Chapter 50Chapter 50
Introduction to Ecology and the Introduction to Ecology and the BiosphereBiosphere
Ecology is the study of…Ecology is the study of…
1.1. distribution and abundance of organismsdistribution and abundance of organisms
2.2. their interactions with other organismstheir interactions with other organisms
3.3. their interactions with their physical their interactions with their physical environmentenvironment
Think about your favorite spot in nature, Think about your favorite spot in nature, and write a summary of what that place and write a summary of what that place is like utilizing all of your sensesis like utilizing all of your senses
Key Terms:Key Terms:Discuss the meaning of the following terms Discuss the meaning of the following terms
within your groupwithin your group1.1. PopulationPopulation2.2. CommunityCommunity3.3. EcosystemEcosystem4.4. BiosphereBiosphere5.5. HabitatHabitat6.6. NicheNiche7.7. AbioticAbiotic8.8. BioticBiotic
1.1. PopulationPopulation – Group of same species living in the same – Group of same species living in the same areaarea
2.2. CommunityCommunity – Group of populations living in the same – Group of populations living in the same areaarea
3.3. EcosystemEcosystem – Interrelationships between the organisms – Interrelationships between the organisms in a community and their physical environmentin a community and their physical environment
4.4. BiosphereBiosphere – All the regions of Earth that contain living – All the regions of Earth that contain living thingsthings
5.5. HabitatHabitat – Type of place where an organisms lives – Type of place where an organisms lives
6.6. NicheNiche – Describes all of the biotic and abiotic resources – Describes all of the biotic and abiotic resources in the environment used by an organismin the environment used by an organism
7.7. AbioticAbiotic – Non living chemical and physical factors – Non living chemical and physical factors
8.8. BioticBiotic – Living organisms in an environment – Living organisms in an environment
Describe how the following terms Describe how the following terms relate to that favorite spot…relate to that favorite spot…
1.1. PopulationPopulation2.2. CommunityCommunity3.3. EcosystemEcosystem4.4. BiosphereBiosphere5.5. HabitatHabitat6.6. NicheNiche7.7. AbioticAbiotic8.8. BioticBiotic
Major Abiotic FactorsMajor Abiotic Factors1.1. TemperatureTemperature
2.2. WaterWater
3.3. SunlightSunlight
4.4. WindWind
5.5. Rocks and SoilRocks and Soil
6.6. Periodic DisturbancesPeriodic Disturbances
These factors play an important role in the climate These factors play an important role in the climate and distribution of organisms around Earthand distribution of organisms around Earth
Global Climate PatternsGlobal Climate Patterns
1.1. The cause of the seasonsThe cause of the seasons
2.2. Global Air Circulation, precipitation, and Global Air Circulation, precipitation, and windswinds
3.3. Rain ShadowsRain Shadows
The Cause of Seasons
Air Circulation and Air Circulation and PrecipitationPrecipitation
Rain Shadow Rain Shadow EffectEffect
BiomesBiomes Biosphere divided into regions (Biosphere divided into regions (Biomes)Biomes) that exhibit that exhibit
common environmental characteristics.common environmental characteristics. Major Biomes:Major Biomes:
Tropical Rain ForestsTropical Rain Forests SavannahsSavannahs Temperate GrasslandsTemperate Grasslands Temperate Deciduous ForestsTemperate Deciduous Forests DesertsDeserts TaigasTaigas TundrasTundras Fresh Water BiomesFresh Water Biomes Marine BiomesMarine Biomes
Tropical Rain ForestTropical Rain Forest
High TemperatureHigh Temperature Heavy RainfallHeavy Rainfall EpiphytesEpiphytes – –
commensalistic plants commensalistic plants that live on other plantsthat live on other plants
SavannahsSavannahs
Grasslands with Grasslands with scattered treesscattered trees
High TemperaturesHigh Temperatures Little WaterLittle Water
Temperate Deciduous ForestsTemperate Deciduous Forests
Warm summers and Warm summers and cold winterscold winters
Moderate PrecipitationModerate Precipitation Tress shed leaves during Tress shed leaves during
winter (adapting for winter (adapting for short days and cold short days and cold temperatures)temperatures)
DesertsDeserts Hot and DryHot and Dry Plant growth limited Plant growth limited
to short periods to short periods following rainsfollowing rains
TaigaTaiga
Coniferous forests Coniferous forests (Pines, firs, and other (Pines, firs, and other needles leaf trees)needles leaf trees)
Cold wintersCold winters Precipitation is in the Precipitation is in the
form of snowform of snow
TundraTundra
Winters so cold Winters so cold that ground that ground freezesfreezes
In summer, In summer, topsoil thaws, but topsoil thaws, but permafrostpermafrost remains frozenremains frozen
Grassland type of Grassland type of community community supported in supported in summersummer
Fresh Water Fresh Water
PondsPonds LakesLakes StreamsStreams RiversRivers
Marine Marine Estuaries Estuaries
(Oceans meet (Oceans meet rivers)rivers)
Intertidal Zones Intertidal Zones (oceans meet (oceans meet land)land)
Continental Continental shelves (shallow shelves (shallow oceans oceans bordering bordering continents)continents)
Coral ReefsCoral Reefs Pelagic Ocean Pelagic Ocean
(deep ocean)(deep ocean)
Behavioral BiologyBehavioral Biology
Chapter 51Chapter 51
Key Topics…Key Topics… Introduction to Behavior and Behavioral EcologyIntroduction to Behavior and Behavioral Ecology LearningLearning Animal CognitionAnimal Cognition Social Behavior and SociobiologySocial Behavior and Sociobiology
This is an interesting chapter, take a look at the This is an interesting chapter, take a look at the diagrams and studies, but we will not be going diagrams and studies, but we will not be going
into it this year in class…into it this year in class…
Population EcologyPopulation Ecology
Chapter 52Chapter 52
Population EcologyPopulation Ecology
Study of growth, abundance, and Study of growth, abundance, and distribution of populationsdistribution of populations
Basic Factors that affect Population Size:Basic Factors that affect Population Size:
1.1. Birth RateBirth Rate
2.2. Death RateDeath Rate
3.3. ImmigrationImmigration
4.4. EmigrationEmigration
Factors that describe Population Factors that describe Population Abundance and DistributionAbundance and Distribution
1.1. Population SizePopulation Size
2.2. Population DensityPopulation Density
3.3. DispersionDispersion
4.4. Age StructureAge Structure
5.5. Survivorship CurvesSurvivorship Curves
How do you think each of the above affect How do you think each of the above affect population abundance/distribution?population abundance/distribution?
1.1. Population Size (n)Population Size (n) = number of individuals in = number of individuals in the populationthe population
2.2. Population DensityPopulation Density = total number of = total number of individuals per area (or volume) occupiedindividuals per area (or volume) occupied
3.3. DispersionDispersion = how individuals in a population = how individuals in a population are distributed. May be clumped, uniform, or are distributed. May be clumped, uniform, or randomrandom
4.4. Age StructureAge Structure = description of the abundance = description of the abundance of individuals at each ageof individuals at each age
Rapidly growing populations have a larger Rapidly growing populations have a larger proportion of population as younger proportion of population as younger
Tiers of equal representation means stable or little Tiers of equal representation means stable or little growth populationsgrowth populations
Age Structure DiagramAge Structure Diagram
Survivorship CurveSurvivorship CurveWhat does this graph tell you about the different
types of survivorship?
5.5. Survivorship CurvesSurvivorship Curves = describe how = describe how mortality of individuals in a species varies mortality of individuals in a species varies during their lifetimes (ex: humans)during their lifetimes (ex: humans)
Type I curvesType I curves – – Most individuals survive to Most individuals survive to middle age, but after that mortality is highmiddle age, but after that mortality is high
Type II curves –Type II curves – length of survivorship is length of survivorship is random (likelyhood of death is same at any random (likelyhood of death is same at any age) (ex: squirrels)age) (ex: squirrels)
Type III curves –Type III curves – Most individuals die Most individuals die young, with only relatively few surviving to young, with only relatively few surviving to reproductive age and beyond (ex: oysters)reproductive age and beyond (ex: oysters)
Survivorship CurveSurvivorship Curve
Reproductive “Episodes” per LifetimeReproductive “Episodes” per Lifetime
Semelparity:Semelparity: Most of their energy is invested in a single Most of their energy is invested in a single
large reproductive effortlarge reproductive effort Ex: Insects, Salmon, annual plantsEx: Insects, Salmon, annual plants Iteroparity:Iteroparity: Produce fewer offspring at a time over a span Produce fewer offspring at a time over a span
of many seasonsof many seasons
How fast do populations grow?How fast do populations grow?
Grow exponentiallyGrow exponentially – as population gets larger, – as population gets larger, it grows faster (more reproducing organisms)it grows faster (more reproducing organisms)
J-Shaped Curve:J-Shaped Curve:
Time
Populationsize
Can this continue forever?
Limits on the EnvironmentLimits on the Environment Limiting factors will stop a population from Limiting factors will stop a population from
increasing… causes an increasing… causes an S – shaped curveS – shaped curve.. Examples: Examples:
Food, Shelter, Sunlight, WaterFood, Shelter, Sunlight, Water Carrying CapacityCarrying Capacity – the number of one – the number of one
species that an environment can support.species that an environment can support.
Time
Populationsize
Carrying Capacity
Biotic PotentialBiotic PotentialMaximum growth rate of a population Maximum growth rate of a population
under ideal conditionsunder ideal conditions Produces a J-shaped curveProduces a J-shaped curve Following Factors Contribute to Biotic Potential:Following Factors Contribute to Biotic Potential:
Age at reproductive maturityAge at reproductive maturity Clutch Size (# of offspring)Clutch Size (# of offspring) Frequency of reproductionFrequency of reproduction Reproductive LifetimeReproductive Lifetime Survivorship of offspring to reproductive maturity Survivorship of offspring to reproductive maturity
Limiting FactorsLimiting Factors
Elements that prevent a population from Elements that prevent a population from attaining its biotic potential attaining its biotic potential
(Limits that effect population size and growth)(Limits that effect population size and growth)Categorized as:Categorized as:
Density-Dependent FactorsDensity-Dependent Factors Density-Independent FactorsDensity-Independent Factors
Intraspecific competition = Intraspecific competition = reliance of reliance of individuals of the same species on the same individuals of the same species on the same limited resourceslimited resources
Density-Dependent FactorsDensity-Dependent FactorsLimiting effect becomes more intense as the Limiting effect becomes more intense as the
population density increasespopulation density increases
Examples:Examples: Parasites and disease (transmission rates Parasites and disease (transmission rates
increase with population density)increase with population density) Competition for resources (food, space, Competition for resources (food, space,
sunlight)sunlight) Toxic effect of waste productsToxic effect of waste products
Density-Independent FactorsDensity-Independent Factors
Factors occur independently of the density of the Factors occur independently of the density of the populationpopulation
Examples:Examples: Natural disasters (fires, earthquakes, volcanic Natural disasters (fires, earthquakes, volcanic
eruptions…)eruptions…) Climate extremes (storms, frosts, drought)Climate extremes (storms, frosts, drought)
Population Growth DescriptionsPopulation Growth Descriptionsr = (r = (births – deaths)births – deaths) / N / N
r = reproductive rate (growth rate)r = reproductive rate (growth rate) N = population size at the beginning of N = population size at the beginning of
interval for which the births and deaths are interval for which the births and deaths are countedcounted
Example:Example: Population of size N = 1000 had 60 briths and Population of size N = 1000 had 60 briths and
10 deaths over a one-year period, then r = (60-10 deaths over a one-year period, then r = (60-10)/1000, or 0.05 per year10)/1000, or 0.05 per year
N / N / t = rN = births – deathst = rN = births – deaths
Intrinsic Rate of Growth = Intrinsic Rate of Growth = maximum maximum reproductive rate reproductive rate (births far outweigh deaths)(births far outweigh deaths)
If deaths exceed births, r will be negative, and the If deaths exceed births, r will be negative, and the population size will decreasepopulation size will decrease
K represents carrying capacity K represents carrying capacity (pop. is at carrying (pop. is at carrying capacity when N = K)capacity when N = K)
2 general patterns of population growth:2 general patterns of population growth:
1.1. Exponential GrowthExponential Growth Reproductive rate > 0Reproductive rate > 0 J-shaped curveJ-shaped curve
2.2. Logistic GrowthLogistic Growth Limiting factors restrict size of population to carrying Limiting factors restrict size of population to carrying
capacitycapacity
rr-selected vs. -selected vs. KK-selected species-selected species Exponential and logistic growth patterns are Exponential and logistic growth patterns are
associated with 2 kinds of life-history strategies:associated with 2 kinds of life-history strategies: rr-selected species -selected species (Rapid Life History)(Rapid Life History) KK-selected species -selected species (Long Life History)(Long Life History)
rr-selected -selected (Opportunistic) (Opportunistic) PopulationsPopulations
Organisms in Organisms in unpredictable environmentsunpredictable environments.. Small bodies Small bodies Mature rapidly (little parental care, if any)Mature rapidly (little parental care, if any) Reproduce early Reproduce early Short life spansShort life spans Lots of offspringLots of offspringExamples:Examples:
mouse, mosquito, fly, weeds, etc.mouse, mosquito, fly, weeds, etc.
K-K-selected selected (Equilibrial)(Equilibrial) Populations PopulationsOrganisms in Organisms in stable environmentsstable environments Population Size remains relatively constant Population Size remains relatively constant
(near carrying capacity, K)(near carrying capacity, K) Large bodies Large bodies Mature slowly Mature slowly Reproduce slowlyReproduce slowly Long life Long life Few offspringFew offspringExamples:Examples:Human, elephant, horse, tree, etc.Human, elephant, horse, tree, etc.
Population CyclesPopulation CyclesDescribe fluctuations in population size in response Describe fluctuations in population size in response
to varying effects of limiting factorsto varying effects of limiting factors Some populations have regular boom and bust Some populations have regular boom and bust
cycles.cycles.When Populations are:When Populations are: Above Carrying capacityAbove Carrying capacity – – limiting factors will exert limiting factors will exert negative feedback on negative feedback on
population growthpopulation growth Below Carrying capacityBelow Carrying capacity – – limiting factors will exert limiting factors will exert little negative feedbacklittle negative feedback
and population and population growth renewsgrowth renews
Human Population GrowthHuman Population Growth Began exponential Began exponential
growth about 1000 growth about 1000 years ago.years ago.
Can it do so Can it do so indefinitely?!?!?!indefinitely?!?!?!
Why or Why not?Why or Why not? How was exponential How was exponential
growth possible for growth possible for this long?this long?
Exponential Human Population GrowthExponential Human Population GrowthMade possible by:Made possible by:1.1. Increases in Food SupplyIncreases in Food Supply – Domesticating – Domesticating
animals and plants and improved technology in animals and plants and improved technology in harvesting, etc.harvesting, etc.
2.2. Reduction in Disease – Reduction in Disease – Advances in medicineAdvances in medicine3.3. Reduction in Human Wastes – Reduction in Human Wastes – developing developing
water purification and sewage systemswater purification and sewage systems4.4. Expansion of Habitat – Expansion of Habitat – Improved housing, Improved housing,
clothing, energy access has made this possible.clothing, energy access has made this possible.These changes have greatly increased the carrying These changes have greatly increased the carrying
capacity of the environmentcapacity of the environment How will things change in the next 1000 years?How will things change in the next 1000 years?
Community EcologyCommunity Ecology
Chapter 53Chapter 53
Community EcologyCommunity Ecology is concerned with the is concerned with the interactions of populationsinteractions of populations
Interspecific competition – Interspecific competition – competition competition between different speciesbetween different species
Ways to resolve competition:Ways to resolve competition:
1) Competitive Exclusion Principle (Gause’s 1) Competitive Exclusion Principle (Gause’s principle):principle):
Two species compete for exactly the same Two species compete for exactly the same resourcesresources
One is likely to be more successful and One is likely to be more successful and outcompetes the otheroutcompetes the other
The other organism is eliminatedThe other organism is eliminated““No two species can sustain coexistence if they No two species can sustain coexistence if they
occupy the same niche”occupy the same niche” Gause tested by mixing two species of Gause tested by mixing two species of
parameciumparamecium..
Resource PartitioningResource Partitioning
2) Resource Partioning:2) Resource Partioning: Species coexist in spite of apparent competition Species coexist in spite of apparent competition Occupy slightly different nichesOccupy slightly different niches Slightly different resources or securing resources Slightly different resources or securing resources
slightly differently minimizes competition and slightly differently minimizes competition and maximizes successmaximizes success
““Resources are divided”Resources are divided”
Ex:Ex: 5 species of warblers coexist in spruce trees by 5 species of warblers coexist in spruce trees by feeding on insects in different regions of the tree feeding on insects in different regions of the tree and using different feeding behaviors and using different feeding behaviors
Character DisplacementCharacter Displacement
3) Character Displacement (niche shift):3) Character Displacement (niche shift): Due to resource partioning, certain Due to resource partioning, certain
characteristics may enable individuals to obtain characteristics may enable individuals to obtain resources more successfullyresources more successfully
Selection reduces competition and leads to a Selection reduces competition and leads to a divergence of featuresdivergence of features
Ex: Two species of Finch live on 2 different Ex: Two species of Finch live on 2 different Galapagos Islands and have similar beaks. On a Galapagos Islands and have similar beaks. On a third island, they coexist, but due to evolution third island, they coexist, but due to evolution the beak of each bird species is different and the beak of each bird species is different and competition is minimizedcompetition is minimized
Fundamental Niche vs. Realized NicheFundamental Niche vs. Realized Niche
4) Realized Niche:4) Realized Niche: Fundamental nicheFundamental niche = niche in the absence of = niche in the absence of
competing speciescompeting species Realized NicheRealized Niche = With competing species, both can = With competing species, both can
coexist by occupying their realized niches.coexist by occupying their realized niches. Part of their existence where Part of their existence where niche overlapniche overlap is absent is absent Competition for resources does not take placeCompetition for resources does not take place
Ex: In experimental conditions, a species of barnacle Ex: In experimental conditions, a species of barnacle can live on rocks exposed to full range of tides, but can live on rocks exposed to full range of tides, but in natural environment it gets outcompeted in lower in natural environment it gets outcompeted in lower tide levels and the first species must survive in tide levels and the first species must survive in realized nicherealized niche, higher tide levels., higher tide levels.
PredationPredation True Predator – True Predator – Kills and eats other animalsKills and eats other animals Parasite – Parasite – spends most/all of life living on spends most/all of life living on
anotehr organim (host) obtaining nourishment anotehr organim (host) obtaining nourishment from the host by feeding on its tissues. (Host from the host by feeding on its tissues. (Host typically doesn’t die)typically doesn’t die)
Parasitoid – Parasitoid – insect that lays eggs on a host insect that lays eggs on a host (usually insect or spider). Eggs hatch and larvae (usually insect or spider). Eggs hatch and larvae obtain nourishment by consuming the tissues of obtain nourishment by consuming the tissues of the host (Host typically dies)the host (Host typically dies)
Herbivore – Herbivore – animal that eats plantsanimal that eats plants
Keystone SpeciesKeystone Species
Keystone species – Keystone species – species that makes an species that makes an unusually strong impact on community structure unusually strong impact on community structure (impact is much larger than its own abundance)(impact is much larger than its own abundance)
Keystone Predators can alter community structure Keystone Predators can alter community structure by moderating competition among prey speciesby moderating competition among prey species
Can Can maintain higher species diversitymaintain higher species diversity (starfish (starfish in intertidal zone)in intertidal zone) or can alter character of whole or can alter character of whole communities communities (beavers constructing dams)(beavers constructing dams)
SymbiosisSymbiosis
Two species that live together in close contact Two species that live together in close contact during a portion (or all) of their lives.during a portion (or all) of their lives.
Three forms of Symbiosis:Three forms of Symbiosis: MutualismMutualism CommensalismCommensalism ParasitismParasitism
What can you group remember about the different What can you group remember about the different types of symbiosis?types of symbiosis?
MutualismMutualism
Both Species benefitBoth Species benefit
Ex: Ex: Acacia trees provide food and housing for ants, ants Acacia trees provide food and housing for ants, ants
kill insects or fungi found on treekill insects or fungi found on tree
CommensalismCommensalism
One species benefits while other neither helped nor One species benefits while other neither helped nor harmedharmed
Ex:Ex: Birds build their nests in treesBirds build their nests in trees Egrets gather around cattle. Birds eat insects aroused by Egrets gather around cattle. Birds eat insects aroused by
cattle, cattle aren’t helped or hurtcattle, cattle aren’t helped or hurt Pilot fish following sharksPilot fish following sharks
ParasitismParasitism Parasite benefits Parasite benefits
while the host is while the host is harmedharmed
Ex:Ex: Tapeworms in the Tapeworms in the
digestive tract of digestive tract of animals stealing animals stealing nutrients from hostnutrients from host
Living RelationshipsLiving RelationshipsType of Type of RelationshipRelationship
Organism Organism AA
Organism Organism BB
ExampleExample
CommensalismCommensalism
MutualismMutualism
Parasitism Parasitism Predator/ PreyPredator/ Prey
benefits
benefits
benefits
benefits
harmed
neutral Spanish Moss/ Trees
Bee / Flower
Tick / Deer
CoevolutionCoevolution The natural selection of characteristics that The natural selection of characteristics that
promote the most successful predators and the promote the most successful predators and the most elusive prey leads to coevolution of most elusive prey leads to coevolution of predators and prey.predators and prey.
Coevolution in one species is a response to Coevolution in one species is a response to new adaptations in another speciesnew adaptations in another species
We will be looking at a couple important We will be looking at a couple important examples of coevolution…examples of coevolution…
1) Secondary Compounds1) Secondary Compounds
Toxic chemicals Toxic chemicals produced in plants that produced in plants that discourage would-be discourage would-be herbivoresherbivores
Ex: Tannins (found in Ex: Tannins (found in oaks) and Nicotine oaks) and Nicotine (found in tobacco) are (found in tobacco) are toxic to herbivorestoxic to herbivores
2) Camouflage (cryptic coloration)2) Camouflage (cryptic coloration)
2) Camouflage2) Camouflage
Any color, pattern, Any color, pattern, shape, or behavior that shape, or behavior that enables an animal to enables an animal to blend in with its blend in with its surroundingssurroundings
Benefits both prey and Benefits both prey and predatorpredator
3) Aposematic Coloration 3) Aposematic Coloration (warning coloration)(warning coloration)
Conspicuous pattern or Conspicuous pattern or coloration of animals coloration of animals that warns predators that that warns predators that they sting, bite, taste they sting, bite, taste bad, or otherwise should bad, or otherwise should be avoidedbe avoided
4) Mimicry4) Mimicry When 2 or more species When 2 or more species
mimic one another in mimic one another in appearanceappearance
Mullerian mimicry =Mullerian mimicry = several animals with same several animals with same special defense special defense mechanism share same mechanism share same coloration coloration (bees, yellow (bees, yellow jackets, wasps…)jackets, wasps…)
Batesian mimicry =Batesian mimicry = Animal without special Animal without special defense mechanism defense mechanism mimics coloration of mimics coloration of animal that possesses animal that possesses defense defense (flies that have (flies that have coloration to mimic bees)coloration to mimic bees)
Ecological SuccessionEcological SuccessionNatural change in species replacements that take Natural change in species replacements that take
place over timeplace over time As succession progresses, species As succession progresses, species diversitydiversity (total (total
# of species)# of species) and total and total biomass biomass (total mass of all (total mass of all living organisms)living organisms) increaseincrease
This increase results in the This increase results in the Climax CommunityClimax Community Residents species can create a disturbance in their Residents species can create a disturbance in their
community in some of the following ways:community in some of the following ways: Changing the substrate texture, soil pH, soil water Changing the substrate texture, soil pH, soil water
potential, and available light; also adjusted potential, and available light; also adjusted through crowdingthrough crowding
Succession ContinuedSuccession Continued Occurs in stagesOccurs in stages Decades or even centuries to see this Decades or even centuries to see this
processprocess Primary SuccessionPrimary Succession – Colonization of – Colonization of
new sitesnew sites by communities of organisms. by communities of organisms. Ex. Lava flowEx. Lava flow
Pioneer SpeciesPioneer Species
The first species to The first species to occur in an area occur in an area after primary after primary succession has succession has occurred.occurred.
Typically r-Typically r-selected speciesselected species
Ex: LichenEx: Lichen
From Pioneer Species to Climax From Pioneer Species to Climax Community…Community…
On Rock:On Rock: Lichen attach to rock and secretes acid that help Lichen attach to rock and secretes acid that help
erode rock into soilerode rock into soil Soil accumulates and bacteria, protists, mosses, and Soil accumulates and bacteria, protists, mosses, and
fungi appear followed by insects and arthropodsfungi appear followed by insects and arthropods Grasses, herbs, weeds, and other r-selected species Grasses, herbs, weeds, and other r-selected species
show upshow up Begin to be replaced by K-selected speciesBegin to be replaced by K-selected speciesOn Sand – On Sand – not much different, but specialized not much different, but specialized
grasses colonize and stabilize sandy areagrasses colonize and stabilize sandy area
Climax CommunityClimax Community
Stable, mature community that Stable, mature community that undergoes little or no change in species.undergoes little or no change in species.
Secondary SuccessionSecondary Succession Sequence of community changes that takes Sequence of community changes that takes
place after a place after a community is disruptedcommunity is disrupted by natural by natural disasters or human actionsdisasters or human actions
Occurs in an area that Occurs in an area that previously contained lifepreviously contained life Less time to reach a climax communityLess time to reach a climax community here here
again because life already existed.again because life already existed. Examples: Forest Fires, hurricanesExamples: Forest Fires, hurricanes
Primary or Secondary Succession?
Primary or Secondary Succession?
EcosystemsEcosystems
Chapter 54Chapter 54
Trophic RelationshipsTrophic Relationships Primary ProducersPrimary Producers (autotrophs)(autotrophs) Primary ConsumersPrimary Consumers (heterotrophs)(heterotrophs) Secondary ConsumersSecondary Consumers Tertiary ConsumersTertiary Consumers DetritivoresDetritivores
Consumers that obtain their energy by consuming Consumers that obtain their energy by consuming dead plants and animals dead plants and animals (includes fungi, bacteria, (includes fungi, bacteria, nematodes, earthworms, insects, and scavengers)nematodes, earthworms, insects, and scavengers)
Food ChainsFood Chains
PathwayPathway showing showing how how MATTERMATTER and and ENERGYENERGY move move through the through the ecosystem.ecosystem.
Some energy is lost Some energy is lost at each link at each link
Food WebFood Web Expresses all possible Expresses all possible
feeding relationships in feeding relationships in a communitya community
Ecological PyramidsEcological Pyramids
Ecological Pyramids (cont’d)Ecological Pyramids (cont’d) Shows energy used in an ecosystemShows energy used in an ecosystem Models the distribution of matter and Models the distribution of matter and
energy within an ecosystem energy within an ecosystem
Several different types of ecological pyramids:Several different types of ecological pyramids:
1.1. Pyramid of EnergyPyramid of Energy
2.2. Pyramid of BiomassPyramid of Biomass
3.3. Pyramid of NumbersPyramid of Numbers
Where does all the energy go?Where does all the energy go? Ecological efficiency = Ecological efficiency = Proportion of energy Proportion of energy
represented at one trophic level that is transferred represented at one trophic level that is transferred to the next levelto the next level
Only about 10% of energy is transferred from one Only about 10% of energy is transferred from one energy level to the next!energy level to the next!
Where does the other 90% go?Where does the other 90% go? Consumed by the individual’s metabolic activitiesConsumed by the individual’s metabolic activities1.1. Why are most food chains only 3 to 5 links long?Why are most food chains only 3 to 5 links long?
2.2. What would be the most effective way to feed the world?What would be the most effective way to feed the world?
3.3. Why are most animals used for food or work primary Why are most animals used for food or work primary consumers?consumers?
Pyramid of Net ProductivityPyramid of Net Productivity
Biogeochemical CyclesBiogeochemical CyclesDescribe the flow of essential elements from the Describe the flow of essential elements from the
environment to living things and backenvironment to living things and back
In studying the cycles, you need to know the In studying the cycles, you need to know the following:following:
Major Storage Locations (Major Storage Locations (reservoirsreservoirs)) Process in which each element is incorporated Process in which each element is incorporated
into organisms (into organisms (assimilationassimilation)) Process in which it returns to the environment Process in which it returns to the environment
((releaserelease))
Hydrologic Cycle Hydrologic Cycle (water cycle)(water cycle)
Water CycleWater CycleReservoirsReservoirs AssimilationAssimilation ReleaseRelease
OceansOceansAirAirGroundwaterGroundwaterGlaciersGlaciersEvaporation, Evaporation, wind, and wind, and precipitation move precipitation move water from oceans water from oceans to landto land
Plants absorb Plants absorb water from the soilwater from the soilAnimals drink Animals drink water or eat other water or eat other organisms organisms
Plants transpirePlants transpireAnimals and Animals and plants Decomposeplants Decompose
Carbon CycleCarbon Cycle
Carbon CycleCarbon CycleReservoirsReservoirs AssimilationAssimilation ReleaseRelease
Atmosphere Atmosphere (CO(CO22))Fossil Fuels Fossil Fuels (coal, oil)(coal, oil)PeatPeatOrganic Material Organic Material (cellulose)(cellulose)
Plants use COPlants use CO22 in in
photosynthesisphotosynthesisAnimals Animals consume plants or consume plants or other animalsother animals
COCO22 released released
through through respiration and respiration and decompositiondecompositionCOCO22 released by released by
burning of fossil burning of fossil fuelsfuels
Nitrogen CycleNitrogen Cycle
Nitrogen CycleNitrogen CycleReservoirsReservoirs AssimilationAssimilation ReleaseReleaseAtmospherAtmosphere (Ne (N22))
Soil (NHSoil (NH44++, ,
NHNH33, NO, NO22--, ,
NONO33--))
Plants absorb nitrogen as Plants absorb nitrogen as NONO33
-- or as NH or as NH44++
Animals eat plants or Animals eat plants or other animalsother animalsNitrogen FixationNitrogen Fixation (N (N22 to to
NHNH44++ by prokaryotes and by prokaryotes and
NN22 to NO to NO33-- by lightning by lightning
and UVand UVNitrification (NHNitrification (NH44
++
NONO22-- NO NO33
-- by nitrifying by nitrifying
bacteriabacteria
Denitrifying Denitrifying bacteriabacteriaDetrivorous Detrivorous bacteria bacteria (ammonificat(ammonification)ion)Animal Animal excretionexcretion
Phosphorus CyclePhosphorus Cycle
Phosphorus CyclePhosphorus Cycle
ReservoirsReservoirs AssimilationAssimilation ReleaseRelease
RocksRocks
Erosion transfers Erosion transfers phosphorus to phosphorus to water and soilwater and soil
Plants absorb Plants absorb inorganic POinorganic PO44
-3-3
from soilsfrom soilsAnimals obtain Animals obtain organic organic phosphorus by phosphorus by eating plants or eating plants or other animalsother animals
Plants and Plants and animals release P animals release P when they when they decomposedecomposeAnimals excrete Animals excrete P in their waste P in their waste productsproducts
Human Impact on the BiosphereHuman Impact on the Biosphere Is human impact on the biosphere good or bad?Is human impact on the biosphere good or bad? What types of human impacts are damaging the What types of human impacts are damaging the
biosphere?biosphere?
1.1. Exponential population growthExponential population growth
2.2. Destruction of habitats for Ag and MiningDestruction of habitats for Ag and Mining
3.3. Pollution from industry and transportationPollution from industry and transportation
Greenhouse EffectGreenhouse Effect Burning of fossil fuels and forests increases COBurning of fossil fuels and forests increases CO22
in the atmospherein the atmosphere Increased COIncreased CO22 traps heat in the earth’s traps heat in the earth’s
atmosphereatmosphere Global temperature begin to rise which would Global temperature begin to rise which would
lead to:lead to: Raised Sea levels Raised Sea levels (melting of more ice)(melting of more ice) Decreased Ag output Decreased Ag output (affecting weather patterns)(affecting weather patterns)
Ozone DepletionOzone Depletion
Ozone layer is upper atmosphere when UV Ozone layer is upper atmosphere when UV reacts with Oreacts with O22 to form O to form O33
Ozone absorbs UV and prevents it from Ozone absorbs UV and prevents it from reaching the surface of earth where it can reaching the surface of earth where it can damage DNA of plants and animalsdamage DNA of plants and animals
Various air pollutants (ex: CFCs) enter upper Various air pollutants (ex: CFCs) enter upper atmosphere and break down ozoneatmosphere and break down ozone
Thinning ozone creates Thinning ozone creates ozone holesozone holes
Acid RainAcid Rain
Burning fossil fuels and other industrial Burning fossil fuels and other industrial processes release air pollutantsprocesses release air pollutants
SOSO22 and NO and NO22 react with water vapor to react with water vapor to
produce sulfuric and nitric acidproduce sulfuric and nitric acid Acids return to earth’s surface and kill plants Acids return to earth’s surface and kill plants
and animals in lakes and riversand animals in lakes and rivers
DesertificationDesertification
Overgrazing of grasslands that border deserts Overgrazing of grasslands that border deserts transform grasslands into desertstransform grasslands into deserts
Agricultural output decreases or native species Agricultural output decreases or native species are lostare lost
DeforestationDeforestation
Clear-cutting of forests causes erosion, Clear-cutting of forests causes erosion, flooding and changes in weather patterns.flooding and changes in weather patterns.
Slash-and-burn method of tropical rain forests Slash-and-burn method of tropical rain forests (for Ag) increases atmospheric CO2(for Ag) increases atmospheric CO2
This technique destroys nutrients and some This technique destroys nutrients and some soils can only support Ag for 1 or 2 yearssoils can only support Ag for 1 or 2 years
PollutionPollution
Air, water, and land pollution contaminate the Air, water, and land pollution contaminate the materials essential to lifematerials essential to life
Many pollutants don’t degrade and remain in Many pollutants don’t degrade and remain in environment for decadesenvironment for decades
Some toxins gets passed down the food chain Some toxins gets passed down the food chain effecting all organisms along the way effecting all organisms along the way – – biological magnificationbiological magnification
Reduction in Species DiversityReduction in Species Diversity
Due to human activities, plants and animals Due to human activities, plants and animals are apparently becoming extinct at a faster rate are apparently becoming extinct at a faster rate than the planet has ever experiencedthan the planet has ever experienced
Many of these species could have possibly Many of these species could have possibly become useful to humans as medicines, foods, become useful to humans as medicines, foods, or industrial products.or industrial products.
Conservation BiologyConservation BiologyChapter 55Chapter 55
Another interesting chapter in what is being Another interesting chapter in what is being done to lessen human impact on the done to lessen human impact on the
globe…but we will not be going into itglobe…but we will not be going into it
