Hello,
Whereby you explain a Shannon index 3 80 and eveness of 0.80 in a floristic assemblage in a degraded environment (subject to desertification). Moreover, the majority of species are therophytes?
Thanks.
Hi There,
I have attached an excel sheet that might help. In it you will find three scenarios (presence of species). In all cases the number of *plants* in the "communities" is the same, but they are arranged differently. You can change the blue numbers to play around with the behaviour of the different indexes.
The diversity you indicate means that you *may* have a fair number of species in your assessment. The evenness index shows that some species are more prevalent than others.
If others are looking at this question - please could you also check the spreadsheet - just in case I made an error in the calculation.
P
Hi,
I think you have not understood my question.
I wanted an ecological explanation: H' and E are theoretically kept in stable assemblies, so stable ecosystems.
I worked in disturbed areas affected by desertification, but planted with different species like prickly pear, pine and olive trees.
In these plantations, H and E have automatically increased in spring (increase therophytes after rain )
My question is: can we speak of a balanced plant assemblage in a degraded environment, disturbed even if planted because the H' and E are elevated?
Thank you.
It looks like I did misunderstand the question.
I am wondering about the conclusion you would like to draw on the basis of the two indexes. I am also not sure what you mean with a 'balanced' system. Do you mean 'stable'
On their own, or in this combination the two indexes will not show you if plant composition is stable or changing e.g. if one species is replaced by another. Such a conclusion is especially risky if you are using the data from one year only and/or you can not relate species presence to other environmental variables.
Hello,
When i obtain these results (H'= 3.80 and E= 0.80 only during spring).
What can i say in this case? How describe this assemblage?
Is it stable or not?
Thank you.
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