Absolute counts or relative abundance for BC distance matrix

[MonicaSteffi]

Dear everyone,

I have a dataset of absolute counts and relative abundance obtained from qPCR experiments. I'm interested in calculating the Bray-Curtis dissimilarity to analyze the community structure across different samples.

I plan to use the vegdist function from the vegan package in R.

My main question is:

Can I use relative abundance data directly with vegdist, or do I take the absolute counts abundances to calculate Bray-Curtis dissimilarity?

I'm particularly interested in understanding if there are any pitfalls or considerations I should be aware of when using relative abundance data for this type of analysis. Any insights or recommendations would be greatly appreciated!

Thanks in advance!