Trends and distribution of muskoxen populations based on Table 3-5. Modified from Cuyler et al. 2020. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 79 - Figure 3.30

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

Population estimates and trends for Rangifer populations of the migratory tundra, Arctic island, mountain, and forest ecotypes where their circumpolar distribution intersects the CAFF boundary. Population trends (Increasing, Stable, Decreasing, or Unknown) are indicated by shading. Data sources for each population are indicated as footnotes. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 70 - Table 3.4

The baseline survey and ongoing monitoring required to adequately describe Arctic arthropod biodiversity and to identify trends is largely lacking. Although some existing publications reporting long-term and extensive sampling exist, they are limited in species level information, taxonomic coverage and/or geographic location/extent (Figure 3-19) STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 44 - Figure 3.19

Regional differences are more pronounced in the insectivore guild (Figure 3-24). Although diversity of waders was moderate in the East Asian–Australasian Flyway, 88% (15 of 17) of taxa with known trends were declining—the largest proportion of any group. Both short-term (the last 15 years) and long-term (more than 30 years) trends were available for 157 taxa. Trends were unchanged over the two time periods for 80% of taxa, improved for 11% and worsened for 9%.. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 56 - Figure 3.24

Trend quality categories are: (1) data are lacking such that trends are unknown, (2) regional and site-specific monitoring allow for assumptions of trend, (3) international monitoring allows estimation of trend direction, and (4) rigorously designed international monitoring programmes yield estimates of precision. Modified from Smith et al. 2020. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapte31 - Page 59 - Figure 3.26

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

There is a great variation and heterogeneity among terrestrial Arctic ecosystems. This is further described as biogeographical areas in the Annotated Checklist of the Pan-Arctic Flora (Elven et al. 2020), as vegetation zones (Walker et al. 2005, Raynolds et al 2019) or as ecoregions recognised by Terrestrial Ecoregions of the World (Olson et al. 2001). The START focuses on high and low Arctic regions consistent with the CAVM’s subzones A to E, as shown in Figure 1-2 and Figure 2-1 STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 2 - Page 19 - Figure 2.1

Vegetation monitoring occurs across the Arctic, but the duration of monitoring efforts is variable and is dependent upon both study design and access to resources. Although many field studies on vegetation have been conducted in the Arctic (Figure 3-5), not all can be considered monitoring since some recorded only select measurements over limited time frames. Studies reporting on abundance and composition of vegetation reflect a larger and more widespread geographical coverage than the typically more site-limited and time-consuming phenology studies (Figure 3-5). Geographical gaps in coverage of Siberia and large parts of the Canadian Arctic are evident. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 34 - Figure 3.5