Fig. 5.

Clustering of admixture groups by environmental factors. Biplots of environmental factors (arrows) used in PCAs of sample locations (points) of a) Chinook, b) coho, and c) sockeye salmon. The environmental factors included those from WorldClim version 2.1, elevation, and distance to the ocean. Environmental factors were simplified as temp. (including annual mean temperature, minimum temperature of the coldest month, maximum temperature of the warmest month, and temperature range), precipitation (including driest month precipitation, wettest month precipitation, and annual precipitation), elevation, and distance to the ocean. These variables were not simplified in Supplementary Fig. 8. Locations were colored by their assignment to admixture genetic groups, but no genetic data were used to produce these PCAs. Only sample sites that had average ancestry values ≥ 0.7 from the LFR, MFR, and UFR genetic groups are shown for simplicity (see Supplementary Fig. 8 for all locations). Each small symbol represents a sampling site, and the larger symbol represents the center of the ellipse if there were enough points to calculate and draw the ellipse (ellipse level 0.4). The LFR group includes coastal sites outside the Fraser River for Chinook and coho salmon.