Comparison of the impacts of elevated CO2 soil gas concentrations on selected European terrestrial environments. (November 2015)

• Record Type: Journal Article
• Authors: West, J.M.; Jones, D.G.; Annunziatellis, A.; Barlow, T.S.; Beaubien, S.E.; Bond, A.; Breward, N.; Coombs, P.; de Angelis, D.; Gardner, A.; Gemeni, V.; Graziani, S.; Green, K.A.; Gregory, S.; Gwosdz, S.; Hannis, S.; Kirk, K.; Koukouzas, N.; Krüger, M.; Libertini, S.; Lister, T.R.; Lombardi, S.; Metcalfe, R.; Pearce, J.M.; Smith, K.L.; Steven, M.D.; Thatcher, K.; Ziogou, F.
• Is Part Of: International journal of greenhouse gas control. Volume 42(2015:Nov.)
• Page Start: 357
• Page End: 371
• Publication Date: 2015-11
• Subjects: CO2 storage -- Leakage -- Site monitoring -- Leakage detection -- Natural systems -- Controlled injection -- Environmental impacts; Greenhouse gases -- Environmental aspects -- Periodicals; Air -- Purification -- Technological innovations -- Periodicals; Gaz à effet de serre -- Périodiques; Gaz à effet de serre -- Réduction -- Périodiques; Air -- Purification -- Technological innovations; Greenhouse gases -- Environmental aspects; Periodicals; 363.73874605
• DOI: 10.1016/j.ijggc.2015.07.020
• Languages: English
• ISSNs: 1750-5836

Abstract

Highlights: Effects of CO2 on pasture land compared at different natural and test injection sites. Natural sites adapted to CO2 whilst test site has not previously experienced CO2 . 10–15% CO2 in root zone appears to be threshold for seeing changes in plant coverage. Tolerant indicator species present at CO2 root zone concentrations above about 35%. Microbiological changes are seen at soil gas CO2 contents above 15–40%. Abstract: Selected European studies have illustrated the impacts of elevated CO2 concentrations in shallow soils on pasture. For the first time, general unified conclusions can be made, providing CO2 thresholds where effects on plants and soil microbiology are observed and making recommendations on how this information can be used when planning projects for CO2 storage. The sites include those where CO2 is being naturally released to the atmosphere from deep geological formations; and a non-adapted site, with no previous history of CO2 seepage, where CO2 has been injected into the unsaturated soil horizon. Whilst soil gas concentrations will be influenced by flux rates and other factors, the results suggest that a concentration of between 10% and 15% CO2 soil gas at 20 cm depth, which is within the root zone, is an important threshold level for observing changes in plant coverage. Site-specific plant 'indicators' are also observed for CO2 concentrations at ≥35%. Microbiological changes are seen where CO2 soil gas concentrations are between 15% and 40%. As part of site characterisation, an evaluation of the risks of leakage and their potential environmental impacts should be undertaken.