Peatland pools are tightly coupled to the contemporary carbon cycle.

Peatlands are globally important stores of soil carbon (C) formed over millennial timescales but are at risk of destabilization by human and climate disturbance. Pools are ubiquitous features of many peatlands and can contain very high concentrations of C mobilized in dissolved and particulate organic form and as the greenhouses gases carbon dioxide (CO ) and methane (CH ). The radiocarbon content ( C) of these aquatic C forms tells us whether pool C is generated by contemporary primary production or from destabilized C released from deep peat layers where it was previously stored for millennia.

Aquatic export of young dissolved and gaseous carbon from a pristine boreal fen: Implications for peat carbon stock stability.

The stability of northern peatland's carbon (C) store under changing climate is of major concern for the global C cycle. The aquatic export of C from boreal peatlands is recognized as both a critical pathway for the remobilization of peat C stocks as well as a major component of the net ecosystem C balance (NECB). Here, we present a full year characterization of radiocarbon content ( C) of dissolved organic carbon (DOC), carbon dioxide (CO ), and methane (CH ) exported from a boreal peatland catchment coupled with C characterization of the catchment's peat profile of the same C species.

Ancient dissolved methane in inland waters revealed by a new collection method at low field concentrations for radiocarbon (C) analysis.

Methane (CH) is a powerful greenhouse gas that plays a prominent role in the terrestrial carbon (C) cycle, and is released to the atmosphere from freshwater systems in numerous biomes globally. Radiocarbon (C) analysis can indicate both the age and source of CH in natural environments. In contrast to CH present in bubbles released from aquatic sediments (ebullition), dissolved CH in lakes and streams can be present in low concentrations compared to carbon dioxide (CO), and therefore obtaining sufficient aquatic CH for radiocarbon (C) analysis remains a major technical challenge.

Regional variation in the biogeochemical and physical characteristics of natural peatland pools.

Natural open-water pools are a common feature of northern peatlands and are known to be an important source of atmospheric methane (CH4). Pool environmental variables, particularly water chemistry, vegetation community and physical characteristics, have the potential to exert strong controls on carbon cycling in pools. A total of 66 peatland pools were studied across three regions of the UK (northern Scotland, south-west Scotland, and Northern Ireland).

Biogeochemistry of "pristine" freshwater stream and lake systems in the western Canadian Arctic.

Climate change poses a substantial threat to the stability of the Arctic terrestrial carbon (C) pool as warmer air temperatures thaw permafrost and deepen the seasonally-thawed active layer of soils and sediments. Enhanced water flow through this layer may accelerate the transport of C and major cations and anions to streams and lakes. These act as important conduits and reactors for dissolved C within the terrestrial C cycle.

Annual variability in the radiocarbon age and source of dissolved CO2 in a peatland stream.

Radiocarbon dating has the capacity to significantly improve our understanding of the aquatic carbon cycle. In this study we used a new passive sampler to measure the radiocarbon ((14)C) and stable carbon (δ(13)C) isotopic composition of dissolved CO(2) for the first time in a peatland stream throughout a complete year (May 2010-June 2011). The in-stream sampling system collected time-integrated samples of CO(2) continuously over approximately 1 month periods.

Stream water hydrochemistry as an indicator of carbon flow paths in Finnish peatland catchments during a spring snowmelt event.

Extreme hydrological events are known to contribute significantly to total annual carbon export, the largest of which in Arctic and boreal catchments is spring snowmelt. Whilst previous work has quantified the export of carbon during snowmelt, the source of the carbon remains unclear. Here we use cation hydrochemistry to trace the primary flowpaths which govern the export of carbon during the snowmelt period; specifically we aim to examine the importance of snowpack meltwater to catchment carbon export.