Canonical correspondence analysis (CCA) triplot results.

CCA constructed from percent abundance data of 28 most abundant species, making up roughly 75% of total population of foraminifera. (A) optimal display for cluster sample (grey symbols) interpretation; (B) optimal display of foraminifera species interpretation. CCA results represent constrained ordination of foraminiferal population numbers, and not principal components analysis (PCA) of environmental variables at each site. Thus, triplots display how foraminiferal community is organized with respect to environmental parameters [47]. Environmental parameters are plotted as vectors (black), samples—labeled with their respective cluster symbols—are represented as points, and abbreviated species names (Table 1 caption) are plotted as points, color-coded according to their respective functional group affiliation (blue, symbiont bearing; red, opportunistic; green, heterotrophic). Permutation tests show high significance for CCA axes in question (S1 Fig).