Abiotic drivers in North America, including (a) long-term average maximum August air temperature, (b) spatial distribution of ice sheets in the last glaciation of the North American Arctic region, and (c) geological setting of bedrock geology underlying North America. Panel (a) source Fick and Hijmans (2017). Panel (b) adapted from: Physical Geology by Steve Earle, freely available at http://open.bccampus.ca. Panel (c) source: Geogratis. State of the Arctic Freshwater Biodiversity Report - Chapter 5 - Page 86 - Figure 5-3

Results of circumpolar assessment of lake littoral benthic macroinvertebrates, indicating (a) the location of littoral benthic macroinvertebrate stations, underlain by circumpolar ecoregions; (b) ecoregions with many littoral benthic macroinvertebrate stations, colored on the basis of alpha diversity rarefied to 80 stations; (c) all ecoregions with littoral benthic macroinvertebrate stations, colored on the basis of alpha diversity rarefied to 10 stations; (d) ecoregions with at least two stations in a hydrobasin, colored on the basis of the dominant component of beta diversity (species turnover, nestedness, approximately equal contribution, or no diversity) when averaged across hydrobasins in each ecoregion. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 65 - Figure 4-29

Local diatom species richness of Arctic diatom assemblages from stream scrapes, showing (left) richness as a function of latitude, and (right) site-specific richness. A LOESS smoother (blue line) with a span of 0.75 and a 95% confidence interval (grey shading) was applied to the data (left) to better highlight the general trend. Coloured circles on the map indicate species richness at the sampling sites. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 37 - Figure 4-10

30-year trends in alpha diversity of benthic macroinvertebrates in the stony littoral zones (1 m depth) of two Scandinavian Arctic/alpine lakes: Lake Abiskojaure (upper panel) and Lake Stor-Tjulträsk (lower panel). State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 71- Figure 4-35

Figure 4 23 Species richness of aquatic macrophytes excluding mosses and algae in five geographic regions of the Arctic. Ame = North America, Fen = Fennoscandia, Far = Faroes, Ice = Iceland, Gre = Greenland. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 55 - Figure 4-22

Figure 4-16 Map showing the magnitude of change in diatom assemblages for downcore samples, with beta diversity used as a measure of the compositional differences between samples at different depths along the core. Boundaries for the beta diversity categories are based on distribution quartiles (0-0.1, 0.1-1.24, 1.24-1.5, >1.5), where the lowest values (blue dots) represent the lowest degree of change in diatom assemblage composition along the length of the core in each lake. State of the Arctic Freshwater Biodiversity Report - Chapter 2 - Page 15 - Figure 2-1

Taxa accumulation curves for (left) lake surface sediment samples, and (right) stream scrapes across the sub-Arctic (blue), Low Arctic (green) and High Arctic (red) ABA Arctic zones. Dashed lines represent the bounds of the 95% confidence interval of the estimate. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 38 - Figure 4-11

Maximum LTA (long-term average) August air temperatures for the circumpolar region, with ecoregions used in the analysis of the SAFBR outlined in black. Source for temperature layer: Fick and Hijmans (2017). State of the Arctic Freshwater Biodiversity Report - Chapter 5 - Page 89 - Figure 5-5

Circumpolar permafrost extent overlain on ecoregions used in SAFBR analysis, indicating continuous (90-100%), discontinuous (50-90%), sporadic (10-50%), and isolated (0-10%) permafrost extent. Source for permafrost layer: Brown et al. (2002). State of the Arctic Freshwater Biodiversity Report - Chapter 5 - Page 89 - Figure 5-6

Figure 4 22 Results of circumpolar assessment of lake macrophytes, indicating (a) the location of macrophyte stations, underlain by circumpolar ecoregions; (b) ecoregions with many macrophyte stations, colored on the basis of alpha diversity rarefied to 70 stations; (c) all ecoregions with macrophyte stations, colored on the basis of alpha diversity rarefied to 10 stations; (d) ecoregions with at least two stations in a hydrobasin, colored on the basis of the dominant component of beta diversity (species turnover, nestedness, approximately equal contribution, or no diversity) when averaged across hydrobasins in each ecoregion. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 54 - Figure 4-22