Are you missing values coded as missing values? That is, are they NA? Such NA-values should be handled by vegan::monoMDS. Naturally, it can be possible that your data set cannot be meaningfully analysed if you have too many missing values or missing values are grouped in peculiar ways. Zero-values are not missing values, but they indicate 0-difference (= identical observations). The missing values must be coded as NA.
cheers, Jari Oksanen ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.