Evidence for the enhanced lability of dissolved organic matter following permafrost slope disturbance in the Canadian High Arctic

Woods, Gwen C.; Simpson, Myrna J.; Pautler, Brent G.; Lamoureux, Scott F.; Lafrenière, Melissa J.; Simpson, André J.

doi:10.1016/j.gca.2011.08.013

Cited by 45 publications

(64 citation statements)

References 81 publications

(145 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The predominance of terrestrial inputs in DOM has also been shown in CBAWO in the main river streams and riverine sediments (Woods et al 2011;Grewer et al 2015). Woods et al (2011) highlighted that plant-derived organic matter originated from primarily non-woody angiosprem vegetation and reported that CBAWO streams exhibited average lignin-derived phenol content relative to total DOC much lower than typical freshwater, with values close to those from heavily glaciated Arctic watersheds.…”

Section: Linking Optical Properties To Dom Compositionmentioning

confidence: 78%

Seasonal hydrology and permafrost disturbance impacts on dissolved organic matter composition in High Arctic headwater catchments

et al. 2017

View full text Add to dashboard Cite

Arctic landscapes are experiencing intense warming and modification of precipitation regimes with climate change. Permafrost disturbances and climate change impacts on hydrology of Arctic watersheds are likely to modify the quantity and composition of exported dissolved organic matter (DOM). In July 2007, intense rainfall and active layer thickening caused widespread active layer detachments at Cape Bounty, Melville Island (Canada). This study investigates the impacts of seasonal hydrology and permafrost disturbance on DOM composition exported from High Arctic headwater catchments. In 2012, streams were sampled from three disturbed catchments and one undisturbed catchment. The composition of DOM was characterized using absorbance and fluorescence spectroscopy. DOM was mostly exported during the spring freshet. Throughout this period, the undisturbed catchment exported humified DOM with high humic-like fluorescence that likely originated from runoff through shallow organic rich soil. In contrast, DOM exported from disturbed catchments was fresher, less humified with a high proportion of low molecular weight humic acid. We demonstrate that disturbed catchments delivered likely more labile DOM derived from either thawed permafrost or enhanced microbial activity. If this labile DOM comes from an ancient pool, as indicated by other studies at this site, disturbances may strengthen the permafrost carbon feedback on climate change.Key words: active layer detachments, dissolved organic matter, fluorescence, High Arctic, parallel factor analysis, PARAFAC.Résumé : Avec le changement climatique, les paysages arctiques connaissent un réchauffe-ment intense et une modification des régimes de précipitation. Les impacts des perturbations du pergélisol et du changement climatique sur l'hydrologie des bassins hydrographiques arctiques vont probablement modifier la quantité et la composition de matière organique dissoute (MOD) exportée. En juillet 2007, des averses intenses et l'épaississement de la couche active ont causé des décollements généralisés de la couche active à Cape Bounty, île Melville (Canada). Cette étude examine les impacts de l'hydrologie saisonnière et de la perturbation du pergélisol sur la composition de la MOD exportée des bassins versants d'amont du HautArctique. En 2012, on a échantillonné des cours d'eau de trois bassins versants perturbés et d'un bassin versant non perturbé. La composition de la MOD a été analysée en utilisant la spectroscopie à fluorescence et l'absorptiométrie. La MOD a surtout été exportée pendant la crue printanière. Pendant cette période, le bassin versant non perturbé a exporté de la MOD humifiée à haute fluorescence telle humique qui provenait probablement de ruissellement par sol riche organique mince. En revanche, la MOD exportée de bassins versants perturbés était plus fraîche, moins humifiée avec une haute proportion d'acide humique à Mots-clés : décollements de la couche active, matière organique dissoute, fluorescence, Haut-Arctique, analyse de facteurs parallèles...

show abstract

Section: Linking Optical Properties To Dom Compositionmentioning

confidence: 78%

Seasonal hydrology and permafrost disturbance impacts on dissolved organic matter composition in High Arctic headwater catchments

et al. 2017

View full text Add to dashboard Cite

show abstract

“…However, due to the complexity of environmental processes, the intensity of this feedback remains unclear (Schaefer et al, 2014;Schuur et al, 2015). Besides being released as greenhouse gases, OM can be redeposited on land or transported to aquatic systems where it can be further mineralized in the water column or buried in sediments (Cory et al, 2013;Letscher et al, 2011;Vonk et al, 2014;Woods et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Transformation of terrestrial organic matter along thermokarst-affected permafrost coasts in the Arctic

Tanski

Lantuit

Ruttor

et al. 2017

Science of The Total Environment

View full text Add to dashboard Cite

“…The WEOM C: N values did not differ between mineral and organic soils (Table 3), which suggest that the WEOM characteristics were similar between both types of soil. However, WEOM C:N values cannot be used as a stand-alone measurement, and a better knowledge of WEOM characteristics (e.g., labile and aromatic structures of WEOM) is still needed (Woods et al, 2011). For mineral surface soils, WSOC values did not significantly differ among sites, whereas WSON 94 / ARCTIC, ANTARCTIC, AND ALPINE RESEARCH values were slightly higher for Truelove (Table 3).…”

Section: Water-extractable Organic Mattermentioning

confidence: 99%

Optimum liquid density in separation of the physically uncomplexed organic matter in Arctic soils

Paré

Bedard‐Haughn

2011

Can. J. Soil. Sci.

View full text Add to dashboard Cite

Paré, M. C. and Bedard-Haughn, A. 2011. Optimum liquid density in separation of the physically uncomplexed organic matter in Arctic soils. Can. J. Soil Sci. 91: 65–68. Using an appropriate density to separate the soil light fraction (LF) and heavy fraction (HF) is an important aspect of the density fractionation technique. The effect of liquid density when separating the physically uncomplexed Arctic soil organic matter (SOM) was tested on three Arctic sites: High-Arctic, Low-Arctic, and Sub-Arctic. Our results showed that selecting the right density to use for Arctic soils is not unequivocal. Nevertheless, based on these two criteria: (1) the difference between the C:N values of the LF and HF needs to be as large as possible, and (2) the C:N value of the whole soil needs to be different from the C:N values of the LF and HF, the optimum density for all of our Arctic sites was between 1.49 and 1.55 g mL−1. We concluded that 1.55g mL−1 was the conservative optimum liquid density to use to separate Arctic SOM light and heavy fractions.

show abstract

Evidence for the enhanced lability of dissolved organic matter following permafrost slope disturbance in the Canadian High Arctic

Cited by 45 publications

References 81 publications

Seasonal hydrology and permafrost disturbance impacts on dissolved organic matter composition in High Arctic headwater catchments

Seasonal hydrology and permafrost disturbance impacts on dissolved organic matter composition in High Arctic headwater catchments

Transformation of terrestrial organic matter along thermokarst-affected permafrost coasts in the Arctic

Optimum liquid density in separation of the physically uncomplexed organic matter in Arctic soils

Contact Info

Product

Resources

About