Aquatic biomass is a major source to particulate organic matter export in large Arctic rivers.

ABSTRACT: Arctic rivers provide an integrated signature of the changing landscape and transmit signals of change to the ocean. Here, we use a decade of particulate organic matter (POM) compositional data to deconvolute multiple allochthonous and autochthonous pan-Arctic and watershed-specific sources. Constraints from carbon-to-nitrogen ratios (C:N), δ¹³C, and Δ¹⁴C signatures reveal a large, hitherto overlooked contribution from aquatic biomass. Separation in Δ¹⁴C age is enhanced by splitting soil sources into shallow and deep pools (mean ± SD: -228 ± 211 vs. -492 ± 173‰) rather than traditional active layer and permafrost pools (-300 ± 236 vs. -441 ± 215‰) that do not represent permafrost-free Arctic regions. We estimate that 39 to 60% (5 to 95% credible interval) o

SUBMITTER: Behnke MI 

PROVIDER: S-EPMC10041151 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature