Alternative transformations of nitrous oxide soil flux data to normal distributions

Abstract

Non-normal distributions of soil N2O fluxes are commonly log transformed prior to statistical analysis. These data are transformed to ensure that analysis of variance and regression based on least squares, meet the assumptions of normality for the distribution of data and equality of variances. Analysis of micrometeorological and static chamber-based fluxes of N2O in Manitoba show that continuous functions such as the Johnson Su and Sl, Generalized Log or normal quantile may be useful as alternatives to the lognormal, which was relatively less effective in transforming data, though each transformation should be evaluated on a case-by-case basis.