Sammanfattning

Climate change is predicted to have far reaching consequences for the mobility of carbon in arctic landscapes. On a regional scale, carbon cycling is highly dependent on interactions between terrestrial and aquatic parts of a catchment. Despite this, studies that integrate the terrestrial and aquatic systems and study entire catchments using site-specific data are rare. In this work, we use data partly published by Lindborg et al. (2016a) to calculate a whole-catchment carbon mass-balance budget for a periglacial catchment in West Greenland. Our budget shows that terrestrial net primary production is the main input of carbon (99% of input), and that most carbon leaves the system through soil respiration (90% of total export/storage). The largest carbon pools are active layer soils (53% of total carbon stock or 13 kg C m (2)), permafrost soils (30% of total carbon stock or 7.6 kg C m (2)) and lake sediments (13% of total carbon stock or 10 kg C m (2)). Hydrological transport of carbon from the terrestrial to aquatic system is lower than in wetter climates, but the annual input of 4100 kg C yr (1) (or 3.5 g C m (2) yr (1)) that enters the lake via runoff is still three times larger than the eolian input of terrestrial carbon. Due to the dry conditions, the hydrological export of carbon from the catchment is limited (5% of aquatic export/storage or 0.1% of total export/storage). Instead, CO2 evasion from the lake surface and sediment burial accounts for 57% and 38% of aquatic export/storage, respectively (or 0.8% and 0.5% of total export/storage), and Two-Boat Lake acts as a net source of carbon to the atmosphere. The limited export of carbon to downstream water bodies make our study system different from wetter arctic environments, where hydrological transport is an important export pathway for carbon. (C) 2019 The Author(s). Published by Elsevier B.V.

Nyckelord

Carbon-budget; Whole catchment; Dry periglacial landscape; Terrestrial; Aquatic

Publicerad i

Science of the Total Environment
2020, Volym: 711, artikelnummer: 134561
Utgivare: ELSEVIER

SLU författare

• Lindborg, Tobias

  • Institutionen för skogens ekologi och skötsel, Sveriges lantbruksuniversitet
    
  • Svensk Kärnbränslehantering AB (SKB)

• Laudon, Hjalmar

  • Institutionen för skogens ekologi och skötsel, Sveriges lantbruksuniversitet
    

Globala målen

Vidta omedelbara åtgärder för att bekämpa klimatförändringarna och dess konsekvenser


UKÄ forskningsämne

Klimatforskning
Oceanografi, hydrologi, vattenresurser
Fysisk geografi


Publikationens identifierare

DOI: https://doi.org/10.1016/j.scitotenv.2019.134561

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/104655