Module 14: Exotic Species Introduction

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Module 14 Exotic Species Introduction

• Cameron, Barney, Puja, Nate, Crystal, Rachael
• Atlantic Forest, Brazil
• SEE-U 2000

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Introduction

• Exotic species currently are the second greatest
  threat to biodiversity behind habitat loss
  (Wilson, 2000)
• Exotic species may greatly affect the level of
  biodiversity in an area (increase/decrease).
  Eucalyptus plantations are very common in Brazil
• Eucalyptus plantations are common in Brazil

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Objective

• This study was designed to measure the
  regeneration of woody species in an Atlantic
  Forest compared to a Eucalyptus spp. plantation
  in order to see the impact of exotic species on
  biodiversity

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Methodology

• Data along 35 meter transects was collected from
  two different forest habitats (Atlantic Forest,
  Eucalyptus plantation) with replicates at each
  site
• Plots of .25m2 were used every 7m to sample
  regeneration of woody plant species
• Insect morphospecies richness and diversity was
  qualitatively measured as an indicator of
  diversity
• Canopy cover was measured using a densiometer at
  7 m intervals
• Leaf litter was measured in order to study the
  conditions conducive to growth of woody species

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Results

• There was a significant difference in canopy
  coverage between sites (Atlantic Forest85,
  Eucalyptus site64, t4.35, plt0.05)
• There was no statistical difference in
  regeneration between the two sites (t-1.53,
  plt0.05)
• The total number of insects found in the Atlantic
  Forest was 39 and in the Eucalyptus forest, 40.

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Abundance of Woody Species
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Abundance of Insects
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Leaf Litter
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Discussion

• The Eucalyptus spp. plantation (exotic) had lower
  amounts of regeneration of woody plants than the
  Atlantic Forest
• The abundance of insects showed little
  difference in number between the two sites
• The Eucalyptus was dominated by an exotic grass
  (molasses), which does not spread if no
  disturbance takes place on site

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Discussion cond

• Exotic species do not necessarily reduce
  biodiversity in an area

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Literature Cited

• Wilson, E.O., (2000) Conserving Earths
  Biodiversity (Island Press Washington D.C.) cd
  rom