Ordinations, which order species/samples along gradients so that objects that are
similar are close together on the gradient, were performed on surface-sediment and rockscrape diatom data. A Correspondence analysis with Hill’s scaling was used when examining the rock scrape and surface-sediment samples using both log and square-root transformations as well as untransformed data, which gave similar results. Principle component analysis (Hill’s scaling, square root transformation) was used to examine differences in the diatom assemblages from the rock scrapes. All ordinations were performed using CANOCO v. 4.5 (ter Braak and Smilauer 2002).