PERMANOVA and PERMDISP both significant

[SoilRotifer (Mike Robeson)]

Hi @rparadiso, the following forum threads should help:

Determining dispersion for beta diversity

Hey all, I have read quite a few other posts on this but I am not sure I understand the solutions fully. To sum up my experiment, I have conditioned soil with different cover crop treatments for 3 months and I want to see if the fungal communities differ under those cover crop treatments. I understand the PERMANOVA results but is there a test to tell if the dispersion in one group is larger than another (if some treatments cluster tightly vs others being spread out on the PCoA)? You can visual…

adonis, betadiver, and betadisp

HI @devonorourke, Thanks for tagging me in this discussion! This is an area I'm getting into and getting excited about; the referenced post was awesome. I think you're looking for two separate functionalities: statistical test and visualization. I think they're closely linked, but slightly different things. As far as I understand, permadisp is the statistical test that measures whether the dispersion of a group of samples in ordination space is different between groups (essentially a measure…

Understanding beta-group-significance PERMANOVA results

Hi, I would like to ask for a clarification for beta-group-significance results. I am comparing samples based on their origin. I evaluated weighted UniFrac beta-diversity metrics, and I plotted a PCoA. Based on that, and on taxonomic classification, I could clearly see samples from one origin being very different to samples from other two origins. Then I wanted to confirm this running a PERMANOVA test. Although the box and whisker plots confirm the results I got with the PCoA, I get all p-value…