The Arctic in the Twenty-First Century: Changing Biogeochemical Linkages across a Paraglacial Landscape of Greenland

Abstract

The Kangerlussuaq area of southwest Greenland encompasses diverse ecological, geomorphic, and climate gradients that function over a range of spatial and temporal scales. Ecosystems range from the microbial communities on the ice sheet and moisture-stressed terrestrial vegetation (and their associated herbivores) to freshwater and oligosaline lakes. These ecosystems are linked by a dynamic glacio-fluvial-aeolian geomorphic system that transports water, geological material, organic carbon and nutrients from the glacier surface to adjacent terrestrial and aquatic systems. This paraglacial system is now subject to substantial change because of rapid regional warming since 2000. Here, we describe changes in the eco- and geomorphic systems at a range of timescales and explore rapid future change in the links that integrate these systems. We highlight the importance of cross-system subsidies at the landscape scale and, importantly, how these might change in the near future as the Arctic is expected to continue to warm.

The distribution and biogeochemical importance of high‐latitude dust in the Arctic and Southern Ocean‐Antarctic regions

“…Anderson et al . [] focus on the area (6000 km 2 ) around Kangerlussuaq, west Greenland, which extends from the Greenland Ice Sheet to the Labrador Sea encompassing glacial outwash plains, moraines, a range of terrestrial ecosystems, and >20,000 lakes. They argue that despite the substantial meltwater discharge from the Greenland Ice Sheet, there is a hydrological disconnect between the ice sheet and adjacent terrestrial ecosystems due to topography and limited hydrological connectivity between the tundra soils and aquatic ecosystems due to low annual precipitation and the presence of continuous permafrost.…”

“…In particular, Anderson et al . [] argue that because phosphorus adsorbs to sediments and particles, dust deposition contributes to P enrichment in catchments and can be a key nutrient subsidy to oligotrophic (nutrient‐poor) lakes. The impact of dust is likely to be determined by not only the amount deposited but also the timing.…”

Structural glaciology of Isunguata Sermia, West Greenland

“…This results in a highly dynamic and variable braided river network that is evolving with seasonal and diurnal glacier discharge and sediment loads. In addition to this, the Kangerlussuaq region experiences continuous permafrost conditions (Anderson et al, 2017). This makes the sediments highly deformable, which further explains the dynamic nature of the channelized proglacial stream network.…”

Climate‐Driven Changes in Dissolved Organic Carbon and Water Clarity in Arctic Lakes of West Greenland

“…Exploration of these links is particularly important, as Arctic lakes are sites of intense carbon cycling and are involved in regulation of carbon dioxide and methane to the global C cycle and C burial in their sediments (Cole et al, ). In response to changing climate, Arctic lake‐landscape interactions will be influential in future global C dynamics (Anderson et al, ; Osburn et al, ; Schuur et al, ).…”

“…Deciphering how climate factors affect the coherence of lake responses in this region will be important for understanding how rapid changes in climate may contribute to shifts in Arctic lake ecology and carbon cycling. Precipitation and temperature anomalies have increased in west Greenland in recent years, and these climatic shifts likely alter terrestrial subsidies to lakes and internal lake processing (Anderson et al, ). As Arctic permafrost thaws, the role of soil‐derived dissolved organic carbon (DOC) for C cycling in Arctic surface fresh waters may intensify (Anderson et al, ).…”