I want to run Redundancy Analysis (RDA) with the abundance of different functional groups of plants (7 groups in total: shrubs, coniferous, forbs, etc.) as my response variables.
I know that, for community data, the Hellinger transformation is a really popular choice. However, the Hellinger transformation is recommanded partly because it doesn't give high weight to rare species by accounting for the presence of numerous zeros in the data matrix.
In my case, I aggregated my species under 7 functional groups. So there is no more thing like a "rare species" or a huge number of zeros in the matrix (even if there are still some).
I am wondering if I still should do a Hellinger transformation on my functional groups' abundances.
Or should I use another transformation, or directly use the raw data into my RDA?