Plantations and Biodiversity

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Plantations and Biodiversity

• S. Sky Stephens and
• 1Northern Arizona University School of Forestry,
  Flagstaff AZ USA

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Human Impacts on Forest Conditions

• Development
• Global Market Demands
• Expanding Agriculture
• Expanding Rangeland
• Plantation Establishment
• Forest Management Practices

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Forest Conversions
Remote sensing survey 1990-2000
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Forested Area

• Natural Forests
• declined by 126 million hectares worldwide
• Deforestation
• Conversion to plantations

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• Plantation Forests
• increased by 32 million hectares
• Afforestation
• Reforestation
• Conversion of natural forest

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Non Forested Areas

• Agriculture
• 1.5 billion hectares
• Rangeland
• Development

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Changing Forest Conditions

• Loss of natural forest area
• associated with decline in habitat and
  biodiversity and ecosystem function
• Increase plantation forest area
• Increase non forested area
• Raised question overstory diversity/land use
  impacts on biodiversity

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Forest Structure Simplification
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Worksheet 1
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Managed Forests - The Good..

• Planted forests to achieve a particular goal
  economic i.e. biomass reforestation water and
  soil conservation
• 3 plantation forests provide 35 of the global
  roundwood
• Plantations alleviate pressures on natural
  forests
• Proper management meet demands for industrial
  fiber on 10 worlds forest area

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the Bad.

• Forest management reduces biodiversity
• Biological deserts

and the Ugly

• Biodiversity assessments have found
  impoverished, marginally different and
  unexpectedly high biodiversity
• Establishing the link between biodiversity and
  forest type

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Literature Review

• Inappropriate comparisons!
• Majority of comparisons
• Exotic plantations to natural/semi natural
  forests
• Few examine a gradient of forest types
• Specific management practices effects

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The next question

• How much can we alter forests?
• Can we add biodiversity back?

?
Managed Forest (plantation)
Non forested (agriculture)
Natural Forest
Forest Complexity
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Worksheet 2
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Field Assessment

• Field Assessment
• Forest type gradient
• Forest Reserve - Bobiri
• Mixed native species plantation
• Exotic plantation
• Citrus plantation
• Agricultural fields
• Biodiversity Assessment
• Pitfall traps
• Ground foraging ants
• Ground foraging beetles

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Results

• Several morphospecies were present at two or more
  land uses
• Unique morphospecies characteristic to each land
  use
• Highest diversity, abundance, unique
  morphospecies were observed at Mixed Native
  Species Plantations

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Experimental Plantations

• Mixed native species plantation model
• Manipulate overstory diversity
• Species composition
• Management practices

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Acknowledgements

• Funding Sources
• International Tropical Timber Organization
• Collaborators
• FORIG
• Drs. J. R. Cobbinah and Paul Bosu