Michael F. Billett

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This review summarizes data on exports of carbon from a large number of temperate and boreal catchments in North America, Europe and New Zealand. Organic carbon losses, usually dominated by dissolved organic matter, show relatively little variation, most catchments exporting between 10 and 100 kg C ha(-1) yr(-1). Inorganic carbon exports occur at a similar(More)
Peatland landscapes typically exhibit large variations in greenhouse gas (GHG) emissions due to microtopographic and vegetation heterogeneity. As many peatland budgets are extrapolated from small-scale chamber measurements it is important to both quantify and understand the processes underlying this spatial variability. Here we carried out a mesocosm study(More)
[1] Boreal streams represent potentially important conduits for the exchange of carbon dioxide (CO2) between terrestrial ecosystems and the atmosphere. The gas transfer coefficient of CO2 (KCO2) is a key variable in estimating this source strength, but the scarcity of measured values in lotic systems creates a risk of incorrect flux estimates even when(More)
The aquatic pathway is increasingly being recognized as an important component of catchment carbon and greenhouse gas (GHG) budgets, particularly in peatland systems due to their large carbon store and strong hydrological connectivity. In this study, we present a complete 5-year data set of all aquatic carbon and GHG species from an ombrotrophic Scottish(More)
[1] The stability of global soil carbon (C) represents a major uncertainty in forecasting future climate change. In the UK, substantial soil C losses have been reported, while at the same time dissolved organic carbon (DOC) concentrations in upland waters have increased, suggesting that soil C stocks may be destabilising in response to climate change. To(More)
Data on small-scale spatial variations in instantaneous fluxes and concentrations of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC) and free carbon dioxide (CO2) are presented for a small acidic headwater stream in NE Scotland. Chloride is used as a conservative element to estimate additional, diffuse inputs of water into the main stem of(More)
Carbon sequestration and storage in peatlands rely on consistently highwater tables. Anthropogenic pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of peat-forming vegetation and exposure of previously anaerobic peat to aerobic decomposition. This can shift peatlands from net CO2 sinks to(More)
Peatland streams typically contain high methane concentrations and act as conduits for the release of this greenhouse gas to the atmosphere. Radiocarbon analysis provides a unique tracer that can be used to identify the methane source, and quantify the time elapsed between carbon fixation and return to the atmosphere as CH4. Few studies – those that have(More)
Forest soil organic horizons from 15 profiles in NE Scotland originally sampled in 1949/50, were resampled in 1987. Analyses of both sets of soils for organic C and N show that although concentrations of the two elements have decreased with time, there has been a large increase in storage due to an increase in O horizon thickness. In most cases surface(More)
Quantifying the sink strength of northern hemisphere peatlands requires measurements or realistic estimates of all major C flux terms. Whilst assessments of the net ecosystem carbon balance (NECB) routinely include annual measurements of net ecosystem exchange and lateral fluxes of dissolved organic carbon (DOC), they rarely include estimates of evasion(More)