Catchment-scale thawing and greening decreases long-term nitrogen export in NE Greenland

TY - JOUR

T1 - Catchment-scale thawing and greening decreases long-term nitrogen export in NE Greenland

AU - Speir, Shannon L.

AU - Tank, Jennifer L.

AU - Pastor, Ada

AU - Muller, Marc F.

AU - Mastepanov, Mikhail

AU - Riis, Tenna

N1 - Publisher Copyright: © 2024 The Author(s). Published by IOP Publishing Ltd

PY - 2024/5/1

Y1 - 2024/5/1

N2 - Climate change is expected to alter nitrogen (N) export from Arctic rivers, with potential implications for fragile coastal ecosystems and fisheries. Yet, the directionality of change is poorly understood, as increased mobilization of N in a ‘thawing’ Arctic is countered by higher rates of vegetative uptake in a ‘greening’ Arctic, particularly in the understudied region of Greenland. We use an unprecedented dataset of long-term (n = 18 years) river chemistry, streamflow, and catchment-scale changes in snow and vegetation to document changing riverine N loss in Greenland. We documented decreasing inorganic and organic N loads, linked to decreasing snow stores, warming soils, and enhanced plant uptake. Higher variability in N export across years also points to the increasing role of high flow events in driving downstream N loss. This alteration in N cycling may significantly reduce both inorganic and organic N transport across the terrestrial-aquatic boundary during the open water season in a rapidly warming Greenland.

AB - Climate change is expected to alter nitrogen (N) export from Arctic rivers, with potential implications for fragile coastal ecosystems and fisheries. Yet, the directionality of change is poorly understood, as increased mobilization of N in a ‘thawing’ Arctic is countered by higher rates of vegetative uptake in a ‘greening’ Arctic, particularly in the understudied region of Greenland. We use an unprecedented dataset of long-term (n = 18 years) river chemistry, streamflow, and catchment-scale changes in snow and vegetation to document changing riverine N loss in Greenland. We documented decreasing inorganic and organic N loads, linked to decreasing snow stores, warming soils, and enhanced plant uptake. Higher variability in N export across years also points to the increasing role of high flow events in driving downstream N loss. This alteration in N cycling may significantly reduce both inorganic and organic N transport across the terrestrial-aquatic boundary during the open water season in a rapidly warming Greenland.

KW - climate change

KW - ecosystem succession

KW - nutrient availability

KW - permafrost

KW - rivers

UR - http://www.scopus.com/inward/record.url?scp=85191238825&partnerID=8YFLogxK

U2 - 10.1088/1748-9326/ad3e8e

DO - 10.1088/1748-9326/ad3e8e

M3 - Letter

AN - SCOPUS:85191238825

SN - 1748-9326

VL - 19

JO - Environmental Research Letters

JF - Environmental Research Letters

IS - 5

M1 - 054031

ER -