Hi!

I’m a bit of a newbie with stats and I’m still trying to fully grasp things. I’m a bit confused on what exactly the test statistics are telling me for PERMANOVA (pseudo-F), ADONIS (R2) and ANOSIM ®, and what exactly I should be using for my question, that is: are there significant differences between locations?

From what I understand of permanova, pseudo-F tells me the ratio of between-group variation and within-group variation. A larger pseudo-F value means that the between-group variation is greater than the within-group variation (so like, the variation between locations is greater than the variation between samples within one location?) But I’m not sure what I’m comparing this number against. Are values 1-3 really low? Also, I noticed that this value is the same as the F.Model value in the ADONIS output. What is the relationship between PERMANOVA and ADONIS?

For ANOSIM, the R-value tells me if groups of samples are significantly different. In my case 0.44…is probably not statistically different? What does it mean that the R-value is 0.7 between two locations but the total R-value is much lower than that? Doesn’t that explain some significant difference?

And for ADONIS, the R2-value tells me how much can be explained by the variable. So in my case, only 19% of variation can be explained by location differences.

Problem is, 0.44 doesn’t seem suuuuper low to me…so I feel like there *is* a difference between locations, but why is the R2 value so low? Am I just being biased and misinterpreting?

Sorry for all the questions!

uu-location-significance-permanova.qzv (385.0 KB)

uu-location-significance-anosim.qzv (385.0 KB)

adonis-uu-location.qzv (260.9 KB)