FIG. 4.

Two-dimensional nonmetric MDS plots for ARISA fragments collected from northern and southern lakes. The symbols are coded to represent the lakes from which profiles were obtained. Lake name abbreviations are listed in Table 1. Because plots were generated from separate ordinations, absolute distances on different plots cannot be considered equal. The arrows indicate the directions in which scores on the various axes increase, and Pearson product-moment correlation coefficients of the axes with various environmental variables are provided. (A) Profiles for northern lakes. Stress = 0.12. (B) Profiles for southern lakes. Stress = 0.13. epi, epilimnion; temp, temperature; DP, dissolved phosphorus; DN, dissolved nitrogen; chl a, chlorophyll a.