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Ecology and Behavior. EOC GOALS for this unit: Develop an understanding of ecological relationships among organisms Develop an understanding of the behavior of organisms, resulting from a combination of heredity and environment. Interrelationships in Ecology. Population Community Ecosystem - PowerPoint PPT Presentation
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Ecology and BehaviorEcology and Behavior
EOC GOALS for this unit:EOC GOALS for this unit:
Develop an understanding of ecological Develop an understanding of ecological relationships among organismsrelationships among organisms
Develop an understanding of the behavior Develop an understanding of the behavior of organisms, resulting from a combination of organisms, resulting from a combination of heredity and environmentof heredity and environment
Interrelationships in EcologyInterrelationships in EcologyPopulationPopulationCommunityCommunityEcosystemEcosystemBiosphereBiosphere
PopulationPopulationMembers of the same species in a given Members of the same species in a given
area.area.Population growth and characteristics are Population growth and characteristics are
the study of population ecologiststhe study of population ecologistsThree Key Features of Populations A
population’s future survival is determined by its size, density, and dispersion.
Exponential Growth Growth Rate The rate of population growth is
the difference between the birthrate and the death rate.
Exponential Growth Curve A J-shaped graph in which the rate of population growth stays the same is known as an exponential growth curve. (increasing)
• Rapidly Growing Populations R-strategists grow exponentially when environmental conditions allow them to reproduce and this often results in temporarily large populations.
Exponential Growth in anr-selected species.
Logistic GrowthLogistic GrowthLeveling off at carrying capacityLeveling off at carrying capacityK = carrying capacity – the number of K = carrying capacity – the number of
organisms a population can sustain.organisms a population can sustain.Slowly Growing Populations = K-
strategists grow slowly, have small population sizes, and their population density are near the carrying capacity.
initial carrying capacity
(or K)
Logistic Growth of a K-selected Species
Community Community
All the populations that live together in a given areaAll the populations that live together in a given area Community interactions involve things like predator-Community interactions involve things like predator-
prey, symbiosis, and competitionprey, symbiosis, and competition Every organism in a community has the following:Every organism in a community has the following:
habitat: place where an organisms liveshabitat: place where an organisms lives niche: an organism’s job; all the resources that an organism usesniche: an organism’s job; all the resources that an organism uses
Type of habitat shapes a community’s structureType of habitat shapes a community’s structure
NicheNiche
Sum of activities and relationships in Sum of activities and relationships in
which a species engages to secure and which a species engages to secure and
use resources necessary for survival and use resources necessary for survival and
reproductionreproduction
Species InteractionsSpecies Interactions
Most interactions are neutral; have no effect on either Most interactions are neutral; have no effect on either
speciesspecies
Interspecific competition has a negative effect on both Interspecific competition has a negative effect on both
speciesspecies
Predation and parasitism both benefit one species at Predation and parasitism both benefit one species at
a cost to anothera cost to another
Symbiosis - Living together for at Symbiosis - Living together for at least some part of the life cycleleast some part of the life cycle
Commensalism, mutualism, and Commensalism, mutualism, and
parasitism are forms of symbiosis parasitism are forms of symbiosis Commensalism helps one species and has no effect Commensalism helps one species and has no effect
on the other on the other
Mutualism helps both speciesMutualism helps both species
Parasitism helps the parasite at the cost of the hostParasitism helps the parasite at the cost of the host
ParasitismParasitism
Parasites drain nutrients from their Parasites drain nutrients from their
hosts and live on or in their bodieshosts and live on or in their bodies
Natural selection favors parasites that Natural selection favors parasites that
do not kill their host too quicklydo not kill their host too quickly
PredationPredation
Predators are animals that feed on other Predators are animals that feed on other
living organismsliving organisms
Predators are free-living; they do not Predators are free-living; they do not
take up residence on their preytake up residence on their prey
Ecosystem Ecosystem
An association of organisms and their An association of organisms and their
physical environment, interconnected by physical environment, interconnected by
ongoing flow of energy and a cycling of ongoing flow of energy and a cycling of
materialsmaterials
Matter (Biogeochemical) Matter (Biogeochemical) CyclingCycling
The flow of a nutrient from the The flow of a nutrient from the
environment to living organisms and back environment to living organisms and back
to the environmentto the environment
Main reservoir for the nutrient is in the Main reservoir for the nutrient is in the
environmentenvironment
Three CategoriesThree Categories
Hydrologic cycleHydrologic cycleWaterWater
Atmospheric cycles Atmospheric cycles Nitrogen and carbonNitrogen and carbon
Sedimentary cycles Sedimentary cycles Phosphorus and sulfurPhosphorus and sulfur
Water (Hydrologic) CycleWater (Hydrologic) CycleAtmosphere
Ocean Land
evaporation from ocean
425,000
precipitation into ocean 385,000
evaporation from land plants (evapotranspiration)
71,000
precipitation onto land 111,000
wind-driven water vapor40,000
surface and groundwater flow 40,000
Figure 48.14Page 876
Carbon CycleCarbon Cycle
Carbon moves through the atmosphere Carbon moves through the atmosphere
and food webs on its way to and from and food webs on its way to and from
the ocean, sediments, and rocksthe ocean, sediments, and rocks
Sediments and rocks are the main Sediments and rocks are the main
reservoirreservoir
Carbon Cycle - LandCarbon Cycle - Land
photosynthesis aerobic respirationterrestrial
rocks
soil water
land food webs
atmosphere
peat, fossil fuels
combustion of wood
sedimentation
volcanic action
death, burial, compaction over geologic time
leaching, runoff
weathering
combustion of fossil fuels
Figure 48.16 Page 878
Nitrogen CycleNitrogen Cycle
Nitrogen is used in amino acids and Nitrogen is used in amino acids and
nucleic acidsnucleic acids
Main reservoir is nitrogen gas in the Main reservoir is nitrogen gas in the
atmosphereatmosphere
Nitrogen CycleNitrogen Cyclegaseous nitrogen (N2)
in atmosphere
NO3-
in soil
nitrogen fixationby industry
fertilizers
NH3-,NH4+
in soil
1. Nitrification leaching
uptake by autotrophs
excretion, death, decomposition
uptake by autotrophs
nitrogen fixation
leaching
ammonification 2. Nitrification
dentrification nitrogenous
wastes, remains
NO2-
in soil
food webs on land
Figure 48.21Page 882
Nitrogen FixationNitrogen Fixation
Plants cannot use nitrogen gasPlants cannot use nitrogen gasNitrogen-fixing bacteria convert Nitrogen-fixing bacteria convert
nitrogen gas into ammonia (NHnitrogen gas into ammonia (NH33))
Ammonia and ammonium can be Ammonia and ammonium can be
taken up by plantstaken up by plants
Human EffectsHuman Effects
Humans increase rate of nitrogen loss by Humans increase rate of nitrogen loss by clearing forests and grasslandsclearing forests and grasslands
Humans increase nitrogen in water and air Humans increase nitrogen in water and air by using fertilizers and by burning fossil by using fertilizers and by burning fossil fuelsfuels
Too much or too little nitrogen can Too much or too little nitrogen can compromise plant healthcompromise plant health
Energy Energy Flow in Flow in
EcosystemEcosystemss
energy input from sun
nutrientcycling
PHOTOAUTOTROPHS(plants, other producers)
HETEROTROPHS(consumers, decomposers)
energy output (mainly heat)
Consumers Consumers Herbivores-plants Herbivores-plants Carnivores-meat Carnivores-meat ParasitesParasites Omnivores-Omnivores-
meat/plants meat/plants DecomposersDecomposers Detritivores Detritivores
SPRING
rodents, rabbits
fruitsinsects
birds
SUMMER
rodents, rabbits
fruits
insects
birds
Seasonal variation in the diet of an omnivore (red fox)
Trophic LevelsTrophic Levels
All the organisms at a trophic level are the All the organisms at a trophic level are the
same number of steps away from the same number of steps away from the
energy input into the systemenergy input into the system
Producers are closest to the energy input Producers are closest to the energy input
and are the first trophic leveland are the first trophic level
Trophic Levels in PrairieTrophic Levels in Prairie
5th
4th
3rd
2nd
1st
Fourth-level consumers (heterotrophs):
Top carnivores, parasites, detritivores, decomposers
Third-level consumers (heterotrophs):Carnivores, parasites, detritivores, decomposers
Second-level consumers (heterotrophs):
Carnivores, parasites, detritivores, decomposers
First-level consumers (heterotrophs):
Herbivores, parasites, detritivores, decomposers
Primary producers (autotrophs):Photoautotrophs, chemoautotrophs
Food ChainFood Chain
A straight-line A straight-line
sequence of who eats sequence of who eats
whom whom
Simple food chains Simple food chains
are rare in natureare rare in nature
marsh hawk
upland sandpiper
garter snake
cutworm
plants
Tall-Grass Prairie Food WebTall-Grass Prairie Food Web
earthworms, insects
sparrow
vole pocketgopher
groundsquirrel
coyotebadgerweasel
spider
frog
snake
sandpiper crow
marsh hawk
grasses, composites
Ecological SuccessionEcological Succession
Change in the composition of species over Change in the composition of species over
timetimeClassical model describes a predictable Classical model describes a predictable
sequence with a stable climax communitysequence with a stable climax community
Types of SuccessionTypes of Succession
Primary succession - new Primary succession - new
environments environments
Secondary succession - Secondary succession -
communities were destroyed or communities were destroyed or
displaceddisplaced
Pioneer SpeciesPioneer Species
Species that colonize barren habitatsSpecies that colonize barren habitats
Lichens, small plants with brief life cyclesLichens, small plants with brief life cycles
Improve conditions for other species who Improve conditions for other species who
then replace themthen replace them
Climax CommunityClimax Community
Stable array of species that persists Stable array of species that persists
relatively unchanged over timerelatively unchanged over timeSuccession does not always move Succession does not always move
predictably toward a specific climax predictably toward a specific climax
community; other stable communities may community; other stable communities may
persistpersist
Cyclic ChangesCyclic Changes
Cyclic, nondirectional changes also shape Cyclic, nondirectional changes also shape
community structurecommunity structureTree falls cause local patchiness in Tree falls cause local patchiness in
tropical foreststropical forestsFires periodically destroy underbrush in Fires periodically destroy underbrush in
sequoia forestssequoia forests
Human Activities/Impacts on Human Activities/Impacts on EnvironmentEnvironment
Global WarmingGlobal WarmingHuman Population GrowthHuman Population GrowthPesticide UsePesticide UseSpecies EffectsSpecies Effects
Carbon in AtmosphereCarbon in Atmosphere
Atmospheric carbon is mainly carbon Atmospheric carbon is mainly carbon dioxidedioxide
Carbon dioxide is added to atmosphereCarbon dioxide is added to atmosphereAerobic respiration, volcanic action, burning Aerobic respiration, volcanic action, burning
fossil fuels fossil fuels Removed by photosynthesisRemoved by photosynthesis
Greenhouse EffectGreenhouse Effect
Greenhouse gases impede the escape Greenhouse gases impede the escape
of heat from Earth’s surfaceof heat from Earth’s surface
Figure 48.18, Page 880
Global WarmingGlobal Warming
Long-term increase in the temperature Long-term increase in the temperature
of Earth’s lower atmosphereof Earth’s lower atmosphere
Figure 48.19, Page 881
Carbon Dioxide IncreaseCarbon Dioxide Increase
Carbon dioxide levels fluctuate seasonally Carbon dioxide levels fluctuate seasonally
The average level is steadily increasingThe average level is steadily increasing
Burning of fossil fuels and deforestation Burning of fossil fuels and deforestation
are contributing to the increaseare contributing to the increase
1999
1975
domestication of plants, animals 9000 B.C. (about 11,000 years ago)
agriculturally based urban societies
beginning of industrial, scientific revolutions
Human Population GrowthHuman Population Growth
DDT in Food WebsDDT in Food Webs Synthetic pesticide banned in United States Synthetic pesticide banned in United States
since the 1970ssince the 1970s
Birds that are carnivores accumulate DDT Birds that are carnivores accumulate DDT in their tissues, produce brittle egg shellsin their tissues, produce brittle egg shells
DDT in an Estuary (1967) – DDT in an Estuary (1967) – Rachel Carson’s Rachel Carson’s Silent SpringSilent Spring
DDT Residues (ppm wet weight of whole live organism)
Ring-billed gull fledgling (Larus delawarensis)Herring gull (Larus argentatus)Osprey (Pandion haliaetus)Green heron (Butorides virescens)Atlantic needlefish (Strongylira marina)Summer flounder (Paralychthys dentatus)Sheepshead minnow (Cyprinodon variegatus)Hard clam (Mercenaria mercenaria)Marsh grass shoots (Spartina patens)Flying insects (mostly flies)Mud snail (Nassarius obsoletus)Shrimps (composite of several samples)Green alga (Cladophora gracilis)Plankton (mostly zooplankton)Water
75.5 18.5 13.8 3.57 2.07 1.28 0.940.420.33 0.30 0.26 0.16 0.083 0.040 0.00005
Keystone SpeciesKeystone Species
A species that can dictate community A species that can dictate community
structurestructure
Removal of a keystone species can cause Removal of a keystone species can cause
drastic changes in a community; can drastic changes in a community; can
increase or decrease diversity increase or decrease diversity
Exotic SpeciesExotic Species
Species that has left its home range Species that has left its home range
and become established elsewhereand become established elsewhere
Becomes part of its new communityBecomes part of its new community
Can have beneficial, neutral, or harmful Can have beneficial, neutral, or harmful
effects on a communityeffects on a community
Endangered SpeciesEndangered Species
A species that is extremely vulnerable to A species that is extremely vulnerable to
extinctionextinction
Close to 70 percent of endangered Close to 70 percent of endangered
species have been negatively affected by species have been negatively affected by
exotic competitorsexotic competitors
Adaptive Responses to Adaptive Responses to Environmental PressuresEnvironmental Pressures
Prey DefensesPrey Defenses
CamouflageCamouflage
Warning colorationWarning coloration
MimicryMimicry
Parental behaviorsParental behaviors
Feeding strategiesFeeding strategies
Behavioral responsesBehavioral responses
Plant Tropisms and other Plant Tropisms and other ResponsesResponses
Phototropism – plants grow towards a light Phototropism – plants grow towards a light sourcesource
Geo/gravitropism – stems grow away from Geo/gravitropism – stems grow away from gravity; roots grow towards gravitygravity; roots grow towards gravity
Types of Animal BehaviorsTypes of Animal BehaviorsTaxisTaxisReflexesReflexes InstinctsInstinctsLearned behaviorsLearned behaviors
Waggle dance signals food >100 meters from hive
Orientation of straight run shows direction to food
Complex Complex Innate Innate
BehaviorsBehaviors
Biological Clocks and Rhythmic Biological Clocks and Rhythmic BehaviorsBehaviors
Circadian rhythms-internal “biological” Circadian rhythms-internal “biological” clocks clocks
Migration-movement during seasonal Migration-movement during seasonal changeschanges
EstivationEstivationhibernationhibernation
Evolution of Behavioral AdaptationsEvolution of Behavioral Adaptations
Courtship ritualsCourtship ritualsCoevolutionCoevolutionSocial behaviorSocial behaviorJane Goodall- said chimpanzees have Jane Goodall- said chimpanzees have
intricate social and personal personalitiesintricate social and personal personalities
Subordinate member of a wolfpack
CoevolutionCoevolution
Joint evolution of two or more species that Joint evolution of two or more species that exert selection pressure on each other as exert selection pressure on each other as an outcome of close ecological interactionan outcome of close ecological interaction
As snail shells have thickened, claws of As snail shells have thickened, claws of snail-eating crabs have become more snail-eating crabs have become more massivemassive
Predator ResponsesPredator Responses
Any adaptation that protects prey may Any adaptation that protects prey may
select for predators that can overcome select for predators that can overcome
that adaptationthat adaptation
Prey adaptations include stealth, Prey adaptations include stealth,
camouflage, and ways to avoid chemical camouflage, and ways to avoid chemical
repellentsrepellents