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1. What is ecology?2. What is a population? 3. What is a community?4. What is an ecosystem?5. What is a biome?6. What is the biosphere?7. What is a food chain?8. What is trophic structure and what are consumers, producers & detritivores9. What ecological issues face us?
Ecology - 10 Questions
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Outline – Principles of Ecology
• Definition of ecology• Hierarchy of relationships
– Populations– Communities– Ecosystems & Biomes– Biosphere
• Ecosystems & Energy Flow• Populations & Exponential Growth
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Ecology
Interactions of living organisms • with each other and • their physical environment.
Distribution and abundance
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Population Survivorship Curves
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Population Pyramids
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United States: Shifting Population Pyramids
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Ecological Footprints
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Ecological/Biological Communities
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Biological Communities
• Community = all the species that occur together in a place.1. Live together2. Evolve together
Competition & Cooperation3. Achieve stability
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Community Ecology - Habitat and Niche
• Habitat is the place where an organism lives.• Niche = the total of all ways a species utilizes
the resources of its environment.
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Community Ecology - Predation
Predation One organism consumes another.A selection pressure
Effect on Prey– favors characteristics in prey that decrease the
probability of capture.– increased fitness of prey.
Effect on Predator– favors characteristics in predator that increase probability
of prey capture.– increased fitness of predator.
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Community Ecology - Plant Defenses Against Herbivores
Morphological thorns, spines
Chemical secondary chemical compoundsMustard oils, cardiac glycosides
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Animal Defenses Against Predators
• Chemical defenses– poisons and stings
• Defensive coloration– Warning coloration = aposematic coloration
individuals advertise poisonous nature– Camouflage coloration = cryptic coloration
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Animal Defenses Against PredatorsMonarch caterpillars eat milkweed plants Some animals benefit from plant toxic secondary compounds
Monarch butterfly Viceroy butterfly
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Community SuccessionCommunity Succession
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Ecological Community Succession
Succession = change in species composition over time
Unstable Stable
Pioneer CommunitiesSimple CommunitiesHigh biotic potentialDon’t compete well
Climax CommunitiesComplex CommunitiesLow biotic potentialCompete well
Characteristics of Succession
Ecosystem
Biomes
Savanna – dry, warm seasonal moisture
Desert – very little moisture Tundra – treeless, permafrost
RainforestRainforest – warm & high moistureBiome Biome –– Large EcosystemLarge Ecosystem
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– Major terrestrial biomes
30ºN
Tropic ofCancer
Equator
Tropic ofCapricorn
30ºS
Tropical forestSavannaDesertChaparral
Temperate grasslandTemperate broadleaf forestConiferous forestTundra
High mountainsPolar ice
Biomes
Mean annual Precipitation (cm)
Mea
n an
nual
Tem
pera
ture
(C)
Biosphere
Trophic level 4Tertiary consumer
Top carnivore
Fungi & Bacteria
Detritivoresdecomposers
Secondary consumerCarnivoreTrophic level 3
Primary consumerHerbivoreTrophic level 2
ProducersTrophic level 1Photosynthesizer
Ecosystem Food Chains & Trophic Levels
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings
Production pyramid explains why meat is a luxury•Field of corn–Supports many more herbivores than carnivores.
CONNECTION
Trophic levelSecondaryconsumers
Primaryconsumers
Producers
Humanvegetarians
Humanmeat-eaters
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1
100
10,000
Ecosystem Calorie Counting
Other Humans
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Serious Ecological Problems• Rainforest Destruction Loss of Biodiversity• Biological Magnification
heavy metals, PCBs, dioxins • Ozone depletion from Fluorocarbons • Acid Rain from Sulfur dioxide • Global Warming from Greenhouse Gases • Population Growth
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END
Introduction to Ecology