A comparison of two diversity indices to decide which habitat at Combretum Park to conserve based on

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A comparison of two diversity indices to decide
which habitat at Combretum Park to conserve based
on insect diversity.

• Shannon-Weaver and IndVal
• Amber Viljoen
• Sam Human
• Kirsty Jardine

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Introduction

• Why insects?
• Bioindicators
• Shannon-Weaver
• IndVal
• How to compare?
• Bland-Altman Plot

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Shannon-Weaver

• Number of species
• Evenness
• If H is high greater species evenness and more
  unique number of species

• pi is the relative abundance of each species
• ni is the number of individuals in each species
• N is the total number of all individuals
• S is the number of species

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IndVal IndValij Aij x Bij x 100

• Calculated independently for each species
• Considers habitat fidelity and specificity
• Indicator value

• Aij Nindividualsij/Nindividualsiij The
  average amount of the species i in group j
• i Mean values for i in all groups
• Bij Nsitesij/NSitesi.ij Number of sites in
  group j where species i is present i Number of
  sites in group j

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Bland-Altman Plot

• Is not an index - PLOT
• Used to compare two existing methods
• Newer method compared to older method
• (x,y)
• X (SWIV)/2
• Y SW - IV

• S (x,y)
• (S1S2)/2 , (S1-S2)

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Bland-Altman Results
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• Site to conserve
• From both SW and IV it is clear to see that not
  only does Felsite Ridge have highest evenness but
  also is one of only sites with an indicator value
  over 70 and therefore we as a group (the two
  blondes and Amber.. Yes it is now 2am on Wed
  morning!) feel that the Felsite should be
  conserved.

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Conclusion

• Felsite rocks!!!!!!!

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Conclusion continuedAnimations just for you
Andrew

• Use both Shannon-Weaver and IndVal!!!!!!!!!!!!!!!!

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This production brought to you by

• Amber Dextrous
• Sam Crack Whore
• Kirsty The other one