Distance‐based multivariate analyses confound location and dispersion effects

Summary 1. A critical property of count data is its mean–variance relationship, yet this is rarely considered in multivariate analysis in ecology. 2. This study considers what is being implicitly assumed about the mean–variance relationship in distance‐based analyses – multivariate analyses based on a matrix of pairwise distances – and what the effect is of any misspecification of the mean–variance relationship. 3. It is shown that distance‐based analyses make implicit assumptions that are typically out‐of‐step with what is observed in real data, which has major consequences. 4. Potential consequences of this mean–variance misspecification are: confounding location and dispersion effects in ordinations;…

• AR
  Australian Research Council