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

Figure 4 12 Diatom groups from Self Organizing Maps (SOMs) in lake top sediments, showing the geographical distribution of each group (with colors representing different SOM groups). State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 39 - Figure 4-12

Fish diversity characteristics in three geographical regions: Alaska, Iceland, and Fennoscandia. Gamma diversity is based the total number of species sampled in hydrobasins of each ecoregion. Alpha diversity shows the mean basin species richness (95% confidence interval) and beta diversity shows the component of beta diversity, nestedness or turnover, that dominated within each of the ecoregions; gamma, alpha, and beta diversity estimates were based on a subset of basins where a minimum of 10 stations were sampled. All maps are drawn to the same scale. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 77 - Figure 4-39

Although the circumpolar countries endeavor to support monitoring programs that provide good coverage of Arctic and subarctic regions, this ideal is constrained by the high costs associated with repeated sampling of a large set of lakes and rivers in areas that often are very remote. Consequently, freshwater monitoring has sparse, spatial coverage in large parts of the Arctic, with only Fennoscandia and Iceland having extensive monitoring coverage of lakes and streams Figure 6-1 Current state of monitoring for lake FECs in each Arctic country. State of the Arctic Freshwater Biodiversity Report - Chapter 6 - Page 93 - Figure 6-1

Figure 3-6. The hypothesized effects of rising mean water temperature on biodiversity (as total species number) of Arctic freshwater ecosystems. A pulsed increase in gamma biodiversity (a) results from the combination of high eurythermal invasion and establishment and low stenothermic loss with increasing water temperature. A pulsed decrease in gamma biodiversity (b) results from the combination of low eurythermal invasion and establishment and high stenothermic loss. Rapid increases (c) and slow increases (d) in species diversity occur, respectively, with high eurythermal invasion and establishment coupled with high stenothermic loss or low eurythermal invasion and establishment and low stenothermic loss as temperatures increase. For simplification, barriers to dispersal have been assumed to be limited in these models. State of the Arctic Freshwater Biodiversity Report - Chapter 3 - Page 23 - Figure 3-6

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

Temporal patterns in % abundance of Atlantic salmon, brown trout, and anadromous Arctic charr from catch statistics in Iceland rivers monitored from 1992 to 2016, showing results from (a) west, (b) south, (c) north, and (d) east Iceland. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 81 - Figure 4-41

Figure 4-7 Circumpolar assessment of lake diatoms, indicating (a) the location of lake diatom stations, underlain by circumpolar ecoregions; (b) ecoregions with many lake diatom stations, colored on the basis of alpha diversity rarefied to 40 stations; (c) all ecoregions with lake diatom 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 (i.e. species turnover, nestedness, approximately equal contribution, or no diversity) when averaged across hydrobasins in each ecoregio. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 35 - Figure 4-7

Although the circumpolar countries endeavor to support monitoring programs that provide good coverage of Arctic and subarctic regions, this ideal is constrained by the high costs associated with repeated sampling of a large set of lakes and rivers in areas that often are very remote. Consequently, freshwater monitoring has sparse, spatial coverage in large parts of the Arctic, with only Fennoscandia and Iceland having extensive monitoring coverage of lakes and streams Figure 6-2 Current state of monitoring for river FECs in each Arctic country State of the Arctic Freshwater Biodiversity Report - Chapter 6 - Page 94 - Figure 6-2

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