geography paper help, 3 pages!

Winter 2017 follow-up courses to Geog 205

• GEOG 180: Global Health – Prof. Matt Sparke • GEOG 280: Digital Geographies – Prof. Sarah Elwood • GEOG 272: Environmental Justice – Prof. Megan Ybarra • GEOG 276: Political Geography – Prof. Michael Brown • GEOG 370: Environmental Conservation – Biermann

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Updates and reminders • Section this week: Island biogeography • Section next week: Discussion and exam review • Second exam coming up: November 16 (Wednesday) • Guest speaker from City of Seattle’s Climate Action Planning

Team on November 18 (Friday)

• Extra credit TONIGHT (7:30 pm): “A Just Transition to a Low Carbon World,” Jacqui Patterson, Kane Hall 120.

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Island BIogeography

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Studying islands helps us to understand patterns of biodiversity in a fragmented world.

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Types of islands

Oceanic islands: Hawaiian Islands

Continental islands: San Juan Islands Virtual islands: Sky

Islands 5

Generalizations About Island Biodiversity

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1. Islands have fewer natIve specIes.

San Juan Island vs. mainland Washington 7

2. Islands have hIgher rates of endemIsm.

e.g. Island marble butterfly: endemic to the San Juan Islands

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3. Island populatIons have less genetIc varIatIon than

contInental populatIons.

Why? a. The Founder Effect b. Smaller populations have less genetic diversity

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4. Island BIodIversIty Is vulneraBle.

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Example: Hawaiian Islands “The Endangered Species Capital of the World”

11 Hawaiian honeycreepers

Example: Hawaiian Islands Percentage of native and non-native bird species infected with malaria at two sites on Mauna Loa

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Site

Site

adaptatIons to Island lIfe • Loss of dispersal ability. Why?

• Lack of predators • Wind • Metabolically expensive

Flightless cormorant

Kiwi bird

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Example: Guam Rail & Brown Tree Snake

Guam Rail (Gallirallus owstoni)

Brown tree snake (Boiga irregularis)

Guam

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adaptatIons to Island lIfe

Gigantism

Giant tortoise from the Seychelles Islands

Komodo dragon

Madagascar hissing cockroach 15

Dwarfism

Bali tiger- extinct 1930s

Pygmy rhinoceros

Key deer

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adaptatIons to Island lIfe

What determines species diversity on islands?

1. Species-area relationship

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Species-Area Relationship As area increases, the number of species present generally increases (to a point.) As area decreases, the number of species present generally decreases. (Discussed in your 10/28 reading “The Forest and the Trees” by Elizabeth Kolbert)

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Number of species on islands with varying degrees of isolation

What determines species diversity on islands? 2. Species-isolation relationship

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Colonization rates on islands

The theory of island biogeography states that species diversity on an island is determined primarily by colonization and extinction rates.

Colonization as a function of distance from mainland • Colonization decreases with isolation

Extinction as a function of island size • Smaller islands provide fewer resources • Smaller islands support fewer individuals within a

species

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Equilibrium Theory of Island Biogeography

Rate

Number of species

Extinction Colonization

Equilibrium 22

Dynamic equilibrium: species composition constantly changes due to colonization and extinction, but the number of species remains stable

But… this understanding of island biodiversity patterns doesn’t account for human activity! Example: Anole lizards in the Caribbean

Shipping connectivity

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Island biogeography in the Anthropocene (see reading for 11/7)

Example: Anole lizards in Trinidad vs. Cuba

Economic isolation now matters as much as or more than geographic isolation for explaining patterns of biodiversity.

Cuba

Trinidad

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Which of the following is not a prediction of the theory of island biogeography? 1. Number of species on an island should eventually become roughly constant through time.

2. Large islands should support more species than small islands.

3. More remote islands should have fewer species than islands close to the mainland.

4. Extinction rates should increase with island size.

Which of the following is NOT a prediction of the theory of island biogeography? 1. Number of species on an island should eventually become roughly constant through time.

2. Large islands should support more species than small islands.

3. More remote islands should have fewer species than islands close to the mainland.

4. Extinction rates should increase with island size.