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

Summary of the taxa accounting for 85% of the lake littoral benthic macroinvertebrates collected in each of several highly-sampled geographic areas, with taxa grouped by order level or higher in pie charts placed spatially to indicate sampling area. Pie charts correspond to (1) Alaska, (2) Greenland low Arctic, (3) Iceland, and (4) Fennoscandia. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 69 - Figure 4-33

Results of circumpolar assessment of lake zooplankton, including crustaceans and rotifers, and indicating (a) the location of zooplankton stations, underlain by circumpolar ecoregions; (b) ecoregions with many zooplankton stations, colored on the basis of alpha diversity rarefied to 25 stations; (c) all ecoregions with zooplankton 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 59 - Figure 4-26

Figure 4 -36 Freshwater fish sampling stations (A), ecoregion alpha diversity in each of the sampled ecoregions, as quantified by estimates of species richness from reference texts (Muus and Dahlstrøm 1971, Scott and Crossman 1973, Mecklenburg et al. 2002) and expert knowledge (academic and government scientists and traditional knowledge) (B), and ecoregion beta diversity (C) characterized according to components of beta diversity as either nestedness, turnover, no diversity (none, beta = 0), or similar nestedness and turnover (nestedness ~ turnover) in the circumpolar Arctic. Ecoregions are shown only where sampling stations occur. Fish sampling stations included in this study assessed complete fish assemblages at each location. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 74 - Figure 4-36

Alpha diversity (rarefied to 10 stations, with error bars indicating standard error) of river benthic macroinvertebrates plotted as a function of the average latitude of stations in each hydrobasin. Hydrobasins are coloured based on country/region State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 68 - Figure 4-32

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

Alpha diversity (± standard error) of river (a) diatoms from benthic samples, (b) benthic macroinvertebrates, and (c) fish within hydrobasins in western and eastern North America plotted as a function of the average latitude in each hydrobasin. Alpha diversity is rarefied to 10 stations per hydrobasin, using size level 5 hydrobasins for all panels. State of the Arctic Freshwater Biodiversity Report - Chapter 5 - Page 85 - Figure 5-2

Figure 3-2 Long-term water temperature trends (1970–2017) for the Utsjoki Nuorgam station in the River Tana (69°N in Finland). The diagram shows the number of days per year with a mean temperature exceeding 5°C. The data show that from 1995 to 2017, this indicator increased by over 0.5 days per year. Data source: Finnish Meteorological Institute. State of the Arctic Freshwater Biodiversity Report - Chapter 3 - Page 15 - Figure 2-1

Results of circumpolar assessment of river benthic macroinvertebrates, indicating (a) the location of river benthic macroinvertebrate stations, underlain by circumpolar ecoregions; (b) ecoregions with many river benthic macroinvertebrate stations, colored on the basis of alpha diversity rarefied to 100 stations; (c) all ecoregions with river 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 67 - Figure 4-30

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