The High–Low Arctic boundary: How is it determined and where is it located?

Abstract

Geobotanical subdivision of landcover is a baseline for many studies. The High–Low Arctic boundary is considered to be of fundamental natural importance. The wide application of different delimitation schemes in various ecological studies and climatic scenarios raises the following questions: (i) What are the common criteria to define the High and Low Arctic? (ii) Could human impact significantly change the distribution of the delimitation criteria? (iii) Is the widely accepted temperature criterion still relevant given ongoing climate change? and (iv) Could we locate the High–Low Arctic boundary by mapping these criteria derived from modern open remote sensing and climatic data? Researchers rely on common criteria for geobotanical delimitation of the Arctic. Unified circumpolar criteria are based on the structure of vegetation cover and climate, while regional specifics are reflected in the floral composition. However, the published delimitation schemes vary greatly. The disagreement in the location of geobotanical boundaries across the studies manifests in poorly comparable results. While maintaining the common principles of geobotanical subdivision, we derived the boundary between the High and Low Arctic using the most up‐to‐date field data and modern techniques: species distribution modeling, radar, thermal and optical satellite imagery processing, and climatic data analysis. The position of the High–Low Arctic boundary in Western Siberia was clarified and mapped. The new boundary is located 50–100 km further north compared to all the previously presented ones. Long‐term anthropogenic press contributes to a change in the vegetation structure but does not noticeably affect key species ranges. A previously specified climatic criterion for the High–Low Arctic boundary accepted in scientific literature has not coincided with the boundary in Western Siberia for over 70 years. The High–Low Arctic boundary is distinctly reflected in biodiversity distribution. The presented approach is appropriate for accurate mapping of the High–Low Arctic boundary in the circumpolar extent.

Landcover succession for recently drained lakes in permafrost on the Yamal peninsula, Western Siberia

“…This supports the generally held assumption that lake drainage introduces landcover heterogeneity into the landscape (Bartsch et al, 2023b). Raynolds et al (2019) A1), this is supported by recently studies, for example showed Ermokhina et al (2023) that the July isotherms of 6 °C are changing northwards. This may have an impact on zone specific results and updated boundaries should be considered for future studies.…”

Current and past climate co-shape community-level plant species richness in the Western Siberian Arctic

“…We found no conclusive evidence that distance to infrastructure affects species richness in Western Siberia. Despite strong evidence of impact of anthropogenic activities on the vegetation of the region (Ektova & Morozova, 2015;Ermokhina et al, 2023;Forbes, 2013;Golovatin et al, 2010;Golovnev et al, 2016;Veselkin et al, 2021), a sensitivity analysis suggests that most of the impact of the distance to infrastructure predictor is attributable to other predictors (Figure S2). At the same time, indirect indicators such as relatively high explained deviance of the distance (11%) show that there might be a potential relationship that cannot be confidently detected with the data available.…”

Current and past climate co‐shape community‐level plant species richness in the Western Siberian Arctic

“…We found no conclusive evidence that distance to infrastructure affects species richness in Western Siberia. Despite strong evidence of impact of anthropogenic activities on the vegetation of the region (Ektova & Morozova, 2015 ; Ermokhina et al., 2023 ; Forbes, 2013 ; Golovatin et al., 2010 ; Golovnev et al., 2016 ; Veselkin et al., 2021 ), a sensitivity analysis suggests that most of the impact of the distance to infrastructure predictor is attributable to other predictors (Figure S2 ). At the same time, indirect indicators such as relatively high explained deviance of the distance (11%) show that there might be a potential relationship that cannot be confidently detected with the data available.…”

“…To estimate community-level species richness, we used geobotanical data from the Russian Arctic Vegetation Archive (Ermokhina et al, 2022;Zemlianskii et al, 2023). These data consist of 1483 Braun-Blanquet plots established in homogenous vegetation collected during the 2005-2017 field campaigns in the Western Siberian tundra (Figure 1) (Zemlianskii et al, 2023).…”