Data reporting and visualization in ecology

Abstract

The reporting and graphing of ecological data and statistical results often leave a lot to be desired. One reason can be a misunderstanding or confusion of some basic concepts in statistics such as standard deviation, standard error, margin of error, confidence interval, skewness of distribution and correlation. The implications of having small sample sizes are also often glossed over. In several situations, statistics and associated graphical representations are made for comparing groups of samples, where the issues become even more complex. Here, I aim to clarify these basic concepts and ways of reporting and visualizing summaries of variables in ecological research, both for single variables as well as pairs of variables. Specific recommendations about better practice are made, for example describing precision of the mean by the margin of error and bootstrapping to obtain confidence intervals. The role of the logarithmic transformation of positive data is described, as well as its implications in the reporting of results in multiplicative rather than additive form. Comments are also made about ordination plots derived from multivariate analyses, such as principal component analysis and canonical correspondence analysis, with suggested improvements. Some data sets from this Kongsfjord special issue are amongst those used as examples.