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

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

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

Rarefied alpha diversity of river (a) diatoms from benthic samples, (b) benthic macroinvertebrates, and (c) fish in ecoregions across North America. State of the Arctic Freshwater Biodiversity Report - Chapter 5- Page 84 - Figure 5-1

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

Figure 3-1 Long-term trends in ice duration (as days) in the River Torne (upper plot) and Lake Torneträsk (lower plot) at 68° north on the Scandinavian peninsula. Lines show smooth fit. Data source: Swedish Meteorological and Hydrological Institute. State of the Arctic Freshwater Biodiversity Report - Chapter 3 - Page 19 - Figure 3-1

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

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 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