Robert MacArthur and Edward O. Wilson The Theory of Island - - PDF document

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Mar 08, 2024 387 likes •530 views

Robert MacArthur and Edward O. Wilson The Theory of Island Biogeography Extinction balances Immigration Assumptions: Increasing isolation decreases immigration rate Increasing size decreases extinction rate Mountaintops as Islands The

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Robert MacArthur and Edward O. Wilson The Theory of Island Biogeography Extinction balances Immigration Assumptions: Increasing isolation decreases immigration rate Increasing size decreases extinction rate

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Mountaintops as Islands

The Species-Area Relationship

Larger “Islands” contain more species POWER LAW S Az One of the oldest patterns in ecology Even works with mountaintops

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Works on real islands too! - Caribbean Bats

log(# species) log(island area)

Forested landscapes in Ohio - Shrinking Islands?

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Carajas, Brazil

1986 1992 Simberloff and Wilson Florida Keys 1970s Experiment: Change the size of small mangrove islands Monitor diversity of arthropods

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controls Reduced islands lost species over time Species-Area Relationship S Az

Back to the Mountains

How will the fauna respond to climate change? THEY ALREADY HAVE! (since the Pleistocene)

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Vegetation zones change with elevation due to climate

Cooler A - rare B - patchy C - connected Warmer B - rare C - patchy (new) D - connected Where’s A? B and C shrink in area

Predicting Responses to Climate Change

Hypothesis: Diversity of mountain islands will shift along Species-Area Relationship S Az

(like the mangroves) Reduced area reduced diversity

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Diversity gradients and climate Currie 1991

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Currie 1991

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$x109 ha-1 yr-1

1,341 684 1,779 1,115 1,692 576 53 17,075 2,277 117 417 124 1,386 721 79 815 3,015

Estimated value of ecosystem services is of the same magnitude as GLOBAL gross national product. Ecosystem services ~$33 trillion (1012) Global GNP ~$18 trillion (1012) This was 1997… Cost of the recent financial crisis was ~$5 trillion

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The ONE - EARTH problem…

Bringing the entire human population up to US energy levels would require approximately 4 Earths

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