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

Monthly snow cover extent (SCE) for Arctic land areas (>60° N) for (a) May and (b) June 1967–2020, a 54-year record. Anomalies are relative to the 1981–2010 average and standardised (each observation was differenced from the mean and divided by the standard deviation, and thus unitless). Solid black and red lines depict 5-year running means for North America and Eurasia, respectively. Filled circles are used to highlight 2020 anomalies. (Mudryk et al. 2020). STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 2 - Page 23 - Figure 2.3

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

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

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

Many population counts of gregarious migrant species, such as waders and geese, take place along the flyways and at wintering grounds outside the Arctic which stresses the importance of continued development of movement ecology studies. Monitoring of FEC attributes related to breeding success and links to environmental drivers within the Arctic takes place in a wide network of research sites across the Arctic, although with low coverage of the high Arctic zone (Figure 3-25) STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 58 - Figure 3.25

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

Number of non-native plant taxa that have become naturalised across the Arctic. No naturalised non-native taxa are recorded from Wrangel Island, Ellesmere Land – northern Greenland, Anabar-Olenyok and Frans Josef Land. Modified from Wasowicz et al. 2020 STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 3 - Page 32 - Figure 3.4

Current state of monitoring for Arctic terrestrial biodiversity FECs in each Arctic state. STATE OF THE ARCTIC TERRESTRIAL BIODIVERSITY REPORT - Chapter 4 - Page 102 - Figure 4.1

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