Krakatau Island Recolonization

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Krakatau Island Recolonization

• Trevor Caskey
• 12/7/06

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History

• Krakatau island lies in the Sundra Straight
  between Java and Sumatra in Indonesia.

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1883 Eruption

• Krakatau erupted on August 27, 1883.
• One of the largest eruption ever recorded.
• As powerful as 21,547 atom bombs
• Destroyed 75 of island and sent a tsunami
  towards Java and Sumatra killing 36 thousand
  people.
• No life remained on the islands.

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Recolonization of the Islands

• The idea of studying and modeling plant dispersal
  on bare islands was brought up my K.W. Dammerman
  in 1948 and made into an actual field of study
  (Biogeography) by MacArthur and Wilson in the
  there book The Theory of Island
  Biogeography(1963).
• Scientists kept surveys of floral and faunal
  species on Krakatau island from 1883 thru the
  1930s which were the basis for Dammerman, and
  MacArthur and Wilsons work.
• From examining the data of these studies, animals
  (esp. birds) were the cause of approx. 25 of the
  plant species.

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PTOTAL Total number of plant species PPLANT
Number of plant species NOT introduced by
birds PBIRDS Number of plant species introduced
by birds B Number of bird species on the
island
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• Metapopulation Modeling
• Basic Levins Model
• dP/dt cP(1-P)-eP
• P population c colonization rate
• e extinction rate
• Mathematically this is the logistic model, which
  is used when there is limited environment for
  growth.

r growth rate P population K Carrying
Capacity
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• This project is aimed at showing even though the
  carrying capacity KPP of the island is limited by
  the area of the island, KPP can be exceeded due
  to bird immigration.
• The Model

r1 Colonization rate Pp r2 Unknown factor to
be found r3 Colonization rate B KPp Carrying
Capacity of Pp KB Carrying Capacity B
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• From linear regression of the data, r1 and r3
  were found.
• r1 0.267186 r3 1.582925
• From looking at the data, KPp and KB are assumed
  to be
• KPp 203 KB 27

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• The solutions of the equations are

To find r2 Set P(t) to 271, B027, Pp0203,
t51(1934) (from the data table) r2 0.110566
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• Given our finished equations, we can now check
  them to see if they match the data.
• At t3 (1886) B(3) 0,
• P(3)