Precipitation and net ecosystem exchange are the most important drivers of DOC flux in upland boreal catchments

Pumpanen, Jukka; Lindén, Aki; Miettinen, Heli; Kolari, Pasi; Ilvesniemi, Hannu; Mammarella, Ivan; Hari, Pertti; Nikinmaa, Eero; Heinonsalo, Jussi; Bäck, Jaana; Ojala, Anne; Berninger, Frank; Vesala, Timo

doi:10.1002/2014jg002705

Cited by 33 publications

(38 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pumpanen et al, 2014). These upstream-of-slump results are consistent with work from other undisturbed permafrost and boreal regions, where precipitation and catchment runoff have been shown to control DOC flux in streams (Prokushkin et al, 2005;Pumpanen et al, 2014) and increasing temperature has been shown to increase DOC production in soils (Christ and David, 1996;Neff and Hooper, 2002;Prokushkin et al, 2005;Yanagihara et al, 2000). They are also consistent with the concept that the permafrost barrier forces runoff to travel through the shallow active layer, where high hydraulic conductivity leads to the rapid transport of carbon into fluvial systems (O'Donnell et al, 2010;Striegl et al, 2005).…”

Section: 3supporting

confidence: 84%

“…However, upstream DOC concentration was positively related to temperature (Table 4), suggesting a link between biological activity and within-soil DOC production (cf. Pumpanen et al, 2014). These upstream-of-slump results are consistent with work from other undisturbed permafrost and boreal regions, where precipitation and catchment runoff have been shown to control DOC flux in streams (Prokushkin et al, 2005;Pumpanen et al, 2014) and increasing temperature has been shown to increase DOC production in soils (Christ and David, 1996;Neff and Hooper, 2002;Prokushkin et al, 2005;Yanagihara et al, 2000).…”

Section: 3supporting

confidence: 83%

See 1 more Smart Citation

Retrogressive thaw slumps temper dissolved organic carbon delivery to streams of the Peel Plateau, NWT, Canada

2017

View full text Add to dashboard Cite

Abstract. In Siberia and Alaska, permafrost thaw has been associated with significant increases in the delivery of dissolved organic carbon (DOC) to recipient stream ecosystems. Here, we examine the effect of retrogressive thaw slumps (RTSs) on DOC concentration and transport, using data from eight RTS features on the Peel Plateau, NWT, Canada. Like extensive regions of northwestern Canada, the Peel Plateau is comprised of thick, ice-rich tills that were deposited at the margins of the Laurentide Ice Sheet. RTS features are now widespread in this region, with headwall exposures up to 30 m high and total disturbed areas often exceeding 20 ha. We find that intensive slumping on the Peel Plateau is universally associated with decreasing DOC concentrations downstream of slumps, even though the composition of slump-derived dissolved organic matter (DOM; assessed using specific UV absorbance and slope ratios) is similar to permafrost-derived DOM from other regions. Comparisons of upstream and downstream DOC flux relative to fluxes of total suspended solids suggest that the substantial fine-grained sediments released by RTS features may sequester DOC. Runoff obtained directly from slump rill water, above entry into recipient streams, indicates that the deepest RTS features, which thaw the greatest extent of buried, Pleistocene-aged glacial tills, release low-concentration DOC when compared to paired upstream, undisturbed locations, while shallower features, with exposures that are more limited to a relict Holocene active layer, have within-slump DOC concentrations more similar to upstream sites. Finally, fine-scale work at a single RTS site indicates that temperature and precipitation serve as primary environmental controls on above-slump and below-slump DOC flux, but it also shows that the relationship between climatic parameters and DOC flux is complex for these dynamic thermokarst features. These results demonstrate that we should expect clear variation in thermokarst-associated DOC mobilization across Arctic regions. However, they also show that within-region variation in thermokarst intensity and landscape composition is critical for determining the biogeochemical response. Geological and climate legacy shape the physical and chemical composition of permafrost and thermokarst potential. As such, these factors must be considered in predictions of land-to-water carbon mobilization in a warming Arctic.

show abstract

Section: 3supporting

confidence: 84%

Section: 3supporting

confidence: 83%

Retrogressive thaw slumps temper dissolved organic carbon delivery to streams of the Peel Plateau, NWT, Canada

2017

View full text Add to dashboard Cite

show abstract

“…Therefore temperature could not explain the residual variations. Precipitation also was shown to be of great importance for DOC dynamics in boreal peatlands (for example Olefeldt et al, 2013;Pumpanen et al, 2014). Discharge during flood events can mobilize large quantities of pre-event water stored in the riparian zone (Kirchner, 2003;Winterdahl et al, 2011), and both the time interval of two successive rainfalls and the quantity of the antecedent rainfall could influence DOC concentrations in the second flood.…”

Section: Discharge and Doc Exportmentioning

confidence: 99%

Hydrological processes and permafrost regulate magnitude, source and chemical characteristics of dissolved organic carbon export in a peatland catchment of northeastern China

Guo

Song

Tan

et al. 2018

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Permafrost thawing in peatlands has the potential to alter the catchment export of dissolved organic carbon (DOC), thus influencing the carbon balance and cycling in linked aquatic and ocean ecosystems. Peatlands along the southern margins of the Eurasian permafrost are relatively underexplored despite the considerable risks associated with permafrost degradation due to climate warming. This study examined dynamics of DOC export from a permafrost peatland catchment located in northeastern China during the 2012 to 2014 growing seasons. The estimated annual DOC loads varied greatly between 3211 and 19 022 kg yr −1 , with a mean DOC yield of 4.7 g m −2 yr −1 . Although the estimated DOC yield was in the lower range compared with other permafrost regions, it was still significant for the net carbon balance in the studied catchment. There were strong linkages between daily discharge and DOC concentrations in both wet and dry years, suggesting a transport-limited process of DOC delivery from the catchment. Discharge explained the majority of both seasonal and interannual variations of DOC concentrations, which made annual discharge a good indicator of total DOC load from the catchment. As indicated by three fluorescence indices, DOC source and chemical characteristics tracked the shift of flow paths during runoff processes closely. Interactions between the flow path and DOC chemical characteristics were greatly influenced by the seasonal thawing of the soil active layer. The deepening of the active layer due to climate warming likely increases the proportion of microbial-originated DOC in baseflow discharge.

show abstract

“…Surface water DOC concentrations are also increasing in many lakes across the boreal zone (Jennings et al, ; Vuorenmaa et al, ), especially in the southern regions of the zone (Monteith et al, ). Rising rainfall may enhance the transport of organic carbon fixed by the terrestrial system to freshwaters (Pumpanen et al, ; Tranvik & Jansson, ). Changing discharge patterns, along with shorter soil frost periods, would be expected to significantly alter the seasonal dynamics of the export of total organic carbon (TOC) from boreal catchments (Blenckner et al, ; Mattsson et al, ).…”

Section: Introductionmentioning

confidence: 99%

Effects of Climate Change on CO₂ Concentration and Efflux in a Humic Boreal Lake: A Modeling Study

et al. 2018

Self Cite

View full text Add to dashboard Cite

Climate change may have notable impacts on carbon cycling in freshwater ecosystems, especially in the boreal zone. Higher atmospheric temperature and changes in annual discharge patterns and carbon loading from the catchment affect the thermal and biogeochemical conditions in a lake. We developed an extension of a one-dimensional process-based lake model MyLake for simulating carbon dioxide (CO 2 ) dynamics of a boreal lake. We calibrated the model for Lake Kuivajärvi, a small humic boreal lake, for the years 2013-2014, using the extensive data available on carbon inflow and concentrations of water column CO 2 and dissolved organic carbon. The lake is a constant source of CO 2 to the atmosphere in the present climate. We studied the potential effects of climate change-induced warming on lake CO 2 concentration and air-water flux using downscaled air temperature data from three recent-generation global climate models with two alternative representative concentration pathway forcing scenarios. Literature estimates were used for climate change impacts on the lake inflow. The scenario simulations showed a 20-35% increase in the CO 2 flux from the lake to the atmosphere in the scenario period 2070-2099 compared to the control period 1980-2009. In addition, we estimated possible implications of different changes in terrestrial inorganic and organic carbon loadings to the lake. The scenarios with plausible increases of 10% and 20% in CO 2 and dissolved organic carbon loadings, respectively, produced increases of 2.1-2.5% and 2.2-2.3% in the annual CO 2 flux.Boreal inland waters must be considered in assessing the effects of climate change on global carbon cycle because of their significant role in carbon cycling (Battin et al., 2009;Downing et al., 2006). Air temperature KIURU ET AL.2212

show abstract

Precipitation and net ecosystem exchange are the most important drivers of DOC flux in upland boreal catchments

Cited by 33 publications

References 52 publications

Retrogressive thaw slumps temper dissolved organic carbon delivery to streams of the Peel Plateau, NWT, Canada

Retrogressive thaw slumps temper dissolved organic carbon delivery to streams of the Peel Plateau, NWT, Canada

Hydrological processes and permafrost regulate magnitude, source and chemical characteristics of dissolved organic carbon export in a peatland catchment of northeastern China

Effects of Climate Change on CO₂ Concentration and Efflux in a Humic Boreal Lake: A Modeling Study

Contact Info

Product

Resources

About

Precipitation and net ecosystem exchange are the most important drivers of DOC flux in upland boreal catchments

Cited by 33 publications

References 52 publications

Retrogressive thaw slumps temper dissolved organic carbon delivery to streams of the Peel Plateau, NWT, Canada

Retrogressive thaw slumps temper dissolved organic carbon delivery to streams of the Peel Plateau, NWT, Canada

Hydrological processes and permafrost regulate magnitude, source and chemical characteristics of dissolved organic carbon export in a peatland catchment of northeastern China

Effects of Climate Change on CO2 Concentration and Efflux in a Humic Boreal Lake: A Modeling Study

Contact Info

Product

Resources

About

Effects of Climate Change on CO₂ Concentration and Efflux in a Humic Boreal Lake: A Modeling Study