For overdispered data, should the correlation matrix exclude zero? I have 4 species and their distributions are overdispersed in space (i.e. lots of zeros). I calculated a Pearson correlation matrix and there is a lot of cluster around the 0s and 1s. Should I eliminate the 0s from the data to calculate the correlation? Or should I use something other than Pearson for overdispered data?


Since your data are clearly not normally distributed, Spearman's correlation coefficient will perform much better than Pearson's.
