Introduction

Randomised complete blocks design is probably the most popular experimental design in ecological studies, because in many cases it controls in a powerful way the environmental heterogeneity (see also Section 3.2). For a univariate response variable (e.g. number of species, total biomass), the results of experiments set in randomised complete blocks are evaluated using a two-way ANOVA without interactions. The interaction mean square is used as the error term – the denominator in the calculation of the F-statistic. In the following tutorial, you will use the program Canoco in a similar way to evaluate the community response (i.e. a multivariate response of the species composition of the vegetation).

This case study is based on an experiment studying the effect of dominant species, plant litter, and moss on the composition of a community of vascular plants, with special attention paid to seedling recruitment. In this way, some of the aspects of the importance of regeneration niche for species coexistence were tested. The experiment was established in four randomised complete blocks, the treatment had four levels, and the response (community composition) was measured once.