Results of circumpolar assessment of river diatoms, indicating (a) the location of river diatom stations, underlain by circumpolar ecoregions; (b) ecoregions with many river diatom stations, colored on the basis of alpha diversity rarefied to 40 stations; (c) all ecoregions with river 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 (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 36 - Figure 4-8

Figure 3-5 Changes in alpha diversity (red line), predator body size (blue dashed line), and ecosystem metabolism (blue solid line) with a shift in glacial cover from high (left) to low (right). Redrawn from Milner et al. (2017). State of the Arctic Freshwater Biodiversity Report - Chapter 3 - Page 22 - Figure 3-5

Summary of the taxa accounting for 85% of the river 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) western Canada, (3) southern Canada, south of Hudson Bay, (4) northern Labrador, (5) Baffin Island, (6) Ellesmere Island, (7) Greenland high Arctic, (8) Greenland low Arctic, (9) Iceland, (10) Svalbard, and (11) Fennoscandia. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 70 - Figure 4-34

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

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

Circumpolar Arctic distribution of Cyanophyceae using presence- absence data from all sites sampled between 1980-2015. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 50 - Figure 4-21

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

Phytoplankton species richness averaged by time periods ±SE in each Arctic region. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 49 - Figure 4-20

Phytoplankton percent composition by dominant classes across the three Arctic regions, using relative presence across stations calculated from from presence – absence data. State of the Arctic Freshwater Biodiversity Report - Chapter 4 - Page 48 - Figure 4-19

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