I'm having a problem with my bloxplot with Shannon's and Simpson's indexs. The value of Shannon for my Community 1 indicating higher diversity (in relation of the Community 2), but have lower value for Simpson. I used 1-D Simpson's index. I done something wrong? or the Shannon's index is inversely proportional to Simpson's index (1-D)?
It might have something to do with the fact that both indices give different importance to the evenness and richness of your communities. Simpson index is more affected by the evenness of the community while Shannon is more affected by the richness. Check the evenness on community one, is there a species that is much more common than the others? that will draw the index down even with similar richness between the communities. I found these resources that might be of help https://www.davidzeleny.net/anadat-r/doku.php/en:div-ind
It might have something to do with the fact that both indices give different importance to the evenness and richness of your communities. Simpson index is more affected by the evenness of the community while Shannon is more affected by the richness. Check the evenness on community one, is there a species that is much more common than the others? that will draw the index down even with similar richness between the communities. I found these resources that might be of help https://www.davidzeleny.net/anadat-r/doku.php/en:div-ind
Shannon is the negative sum of the proportions of species times the natural log of the proportions. But Simpson is the inverse of the sum of the squared proportions. So almost an inverse relationship but not quite :)
http://entnemdept.ufl.edu/hodges/protectus/lp_webfolder/9_12_grade/student_handout_1a.pdf
Thank you both. I'll continue investigating what's comming wrong. Thanks once more, in this case for the links you two sent me.@
The key point here is also determining whether you are anywhere near the diversity asymptote in rarefaction curves or species accumulation curves (reservoir curves), because the slope of the curve that represents the diversity of your samples reflects uniformity to some extent. You must also clearly distinguish between the diversity of species or taxa (simply the number of taxa present, regardless of their abundance and therefore uniformity) and the diversity of heterogeneity (including abundance and therefore including a component of uniformity).
I also suggest EstimateS software:
http://viceroy.eeb.uconn.edu/estimates/
There is a nice approach of LIU and his diversity monitoring model (DIMOmodel; see: Q Liu (1995): A model for species diversity monitoring at community level and its application. Environmental Monitoring and Assessment, 34, 271–287). We used this approach recently for comparing diversity of vascular plants in 15 different short rotation coppice (SRC) sites in Sweden and Germany with varying abundances (see: S Baum, A Bolte, M Weih (2012): High value of short rotation coppice plantations for phytodiversity in rural landscapes. GCB Bioenergy 4: 728-738)
Regards, Sergey
Dear Pushkin Sergey Viktorovich ! Thank you for information. Best wishes, Ozodbek.
Please have a look- http://viceroy.eeb.uconn.edu/estimates/
who is responsible for the latest research conducted? it is interesting all
I suggest reading Roswell's new paper on diversity indices. Very practical and I think you will find it helpful. This was published (Open Access) in the latest issues of OIKOS 130:321-338. The doi is doi: 10.1111/oik.07202
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