Negligible cycling of terrestrial carbon in many lakes of the arid circumpolar landscape

Nature Geoscience
By: , and 

Links

Abstract

High-latitude environments store nearly half of the planet’s below-ground organic carbon (OC), mostly in perennially frozen permafrost soils. Climatic changes drive increased export of terrestrial OC into many aquatic networks, yet the role that circumpolar lakes play in mineralizing this carbon is unclear. Here we directly evaluate ecosystem-scale OC cycling for lakes of interior Alaska. This arid, low-relief lake landscape is representative of over a quarter of total northern circumpolar lake area, but is greatly under-represented in current studies. Contrary to projections based on work in other regions, the studied lakes had a negligible role in mineralizing terrestrial carbon; they received little OC from ancient permafrost soils, and had small net contribution to the watershed carbon balance. Instead, most lakes recycled large quantities of internally derived carbon fixed from atmospheric CO2, underscoring their importance as critical sites for material and energy provision to regional food webs. Our findings deviate from the prevailing paradigm that northern lakes are hotspots of terrestrial OC processing. The shallow and hydrologically disconnected nature of lakes in many arid circumpolar landscapes isolates them from terrestrial carbon processing under current climatic conditions.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Negligible cycling of terrestrial carbon in many lakes of the arid circumpolar landscape
Series title Nature Geoscience
DOI 10.1038/s41561-019-0299
Volume 12
Year Published 2019
Language English
Publisher Springer Nature
Contributing office(s) WMA - Earth System Processes Division
Description 6 p.
First page 180
Last page 185