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 4-1 A generic food web diagram for a lake or river, indicating the basic trophic levels (boxes) and energy flow (arrows) between those levels. Reproduced from Culp et al. (2012a). State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 25 - Figure 4-1

Temporal patterns in % abundance of Atlantic salmon, brown trout, and anadromous Arctic charr from catch statistics in northern Norway rivers monitored from 1993 to 2016, including basins dominated by (a) rivers and (b) lakes. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 81- Figure 4-42

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

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

Box plot represents the homogeneity of assemblages in high Arctic (n=190), low Arctic (n=370) and sub-Arctic lakes (n=1151), i.e., the distance of individual lake phytoplankton assemblages to the group centroid in multivariate space. The mean distance to the centroid for each of the regions can be seen as an estimated of beta diversity, with increasing distance equating to greater differences among assemblages. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 48 - Figure 4-18

Redundancy analysis of percentage species taxa share (taxa richness relative to richness of all taxa) among 5 FECs (phytoplankton, macrophytes, zooplankton, benthic macroinvertebrates and fish) in 13 Fennoscandian lakes (panels A and B) and among 3 FECs in 39 Fennoscandian lakes (panels C and D).The upper panels show lake ordinations, while the bottom panels show explanatory environmental variables (red arrows), as indicated by permutation tests (p < 0.05). Avg%Richness: average species taxa richness as a percentage of richness of all FECs (i.e., including benthic algae if present); %Richness BMI: relative taxa share in benthic macroinvertebrates; %EvergreenNLF: percentage cover of evergreen needle-leaf forests. State of the Arctic Freshwater Biodiversity Report - Chapter 5 - Page 87 - Figure 5-4

Box-plots of taxa richness (average per lake) by Arctic regions for rotifers (left) and crustaceans (right). Crustacean taxa are restricted to taxa within Calanoida, Cyclopoida and Cladocera. Samples with only a single taxon have been excluded. Boxes represent median and interquartile range. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 60 - Figure 4-27

Results of circumpolar assessment of lake zooplankton, focused just on crustaceans, and indicating (a) the location of crustacean zooplankton stations, underlain by circumpolar ecoregions; (b) ecoregions with many crustacean zooplankton stations, colored on the basis of alpha diversity rarefied to 25 stations; (c) all ecoregions with crustacean 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 58 - Figure 4-25

Figure 4-13 Number of deep lakes (red), shallow lakes (blue), and ponds (brown) in each geographical zone (BF, T, LA, HA). BF = Boreal Forest, T =Transition Zone, LA = Low Arctic, HA = High Arctic. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 40 - Figure 4-13