Population Survivorship Curves Ecology 178 Fall 2008/B178F0… · • Ecosystems & Energy Flow ... Monarch butterfly Viceroy butterfly 15 Community Succession 16. ... Primary consumer

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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