The Arctic terrestrial food web includes the exchange of energy and nutrients. Arrows to and from the driver boxes indicate the relative effect and counter effect of different types of drivers on the ecosystem. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 2 - Page 26- Figure 2.4

Geographic area covered by the Arctic Biodiversity Assessment and the CBMP–Terrestrial Plan. Subzones A to E are depicted as defined in the Circumpolar Arctic Vegetation Map (CAVM Team 2003). Subzones A, B and C are the high Arctic while subzones D and E are the low Arctic. Definition of high Arctic, low Arctic, and sub-Arctic follow Hohn & Jaakkola 2010. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 1 - Page 14 - Figure 1.2

Marine primary productivity is not available from the NASA Ocean Color website. Currently the best product available for marine primary productivity is available through Oregon State University’s Ocean Productivity Project. A monthly global Net Primary Productivity product at 9 km spatial resolution has been selected for this analysis. The algorithm used to create the primary productivity is a Vertically Generalized Production Model (VGPM) created by Behrenfeld and Falkowski (1997). It is a “chlorophyll-based” model that estimates net primary production from chlorophyll using a temperature-dependent description of chlorophyll photosynthetic efficiency (O’Malley 2010). Inputs to the function are chlorophyll, available light, and photosynthetic efficiency.

The CBMP–Terrestrial Plan identifies five FECs for monitoring terrestrial birds; herbivores, insectivores, carnivores, omnivores and piscivores. Due to their migratory nature, a wider range of drivers, from both within and outside the Arctic, affect birds and their associated FEC attributes compared to other terrestrial FECs. Figure 3-21 illustrates a conceptual model for Arctic terrestrial birds that includes examples of FECs and key drivers. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 46 - Figure 3.21

Several smaller populations of caribou inhabit sub-Arctic portions of Alaska, including five populations along the Aleutian Archipelago and west coast. These populations are considered part of the migratory tundra ecotype based on genetics, although in some instances their ecology and habitat are similar to the mountain caribou ecotype found in western Canada. Population dynamics and trends for these populations are variable (Figure 3-29). They are managed by the Alaska Department of Fish and Game through hunting quotas. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 72 - Figure 3.29

The Snow Covered Area product is based on a Normalized Difference Snow Index(NDSI), which is similar to NDVI, but exploits different bands in the equation (Equation 3),namely Green (Band 4) and Short Wavelength Near-infrared (SWNIR, Band 6). It isimportant to note that the Band 6 sensor on MODIS Aqua malfunctioned shortly after launch,so Snow Covered Area from the Aqua sensor is calculated using Bands 3 and 7. This mayintroduce errors in identifying snow in vegetated areas, as the use of Band 7 results in falsesnow detection. For this reason the MODIS Terra product has been provided for the CAFF-system.

Temporal trends of arthropod abundance, 1996–2009. Estimated by the number of individuals caught per trap per day during the season from four different pitfall trap plots, each consisting of eight (1996–2006) or four (2007–2009) traps. Modified from Høye et al. 2013. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 41 - Figure 3.16

Rates of change among different terrestrial parameters, using average annual standardised data for the pan-Arctic. *identifies parameters with statistically significant trends. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 95 - Figure 3.33

Trends in total abundance of moths and species richness, from two locations in Iceland, 1995–2016. Trends differ between locations. The solid and dashed straight lines represent linear regression lines which are significant or non-significant, respectively. Modified from Gillespie et al. 2020a. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 41 - Figure 3.14

Lemmings are currently being monitored at 38 sites. Their status and trends were determined based on data from these sites as well as recent data (since 2000) from an additional 11 previous monitoring sites (Figure 3-31). Of those sites monitored, Fennoscandia is overrepresented relative to the geographical area it covers, whereas Russia is underrepresented. Based on the skewed geographical coverage, more information is available for some species of lemmings than others, particularly the Norwegian lemming. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 80 - Figure 3.31