The Open UniversitySkip to content

Acid rain links to CH4 emissions from wetlands

Gauci, Vincent (2001). Acid rain links to CH4 emissions from wetlands. PhD thesis. The Open University.

Full text available as:
PDF (Version of Record) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (16MB) | Preview
Google Scholar: Look up in Google Scholar


A variety of approaches, spanning a range of spatial and temporal scales, were applied to the investigation of the effects of low dose SO42- deposition, at rates comparable to those experienced in acid rain impacted areas, on methane (CH4) emissions from natural wetlands.

Over two years of experimental manipulation of SO42- deposition to a peatland in northeast Scotland, CH4 emissions were suppressed by around 40%. There was no significant difference in suppression of CH4 flux within the sol- deposition range of 25-100 kg-S ha-1yr-1. In a similar short-term controlled environment SO42- manipulation experiment, the suppressive effect of SO42- was found to be independent of the simulated SO42- deposition rate within a range of 15-100 kg-S ha-1yr-1. The possibility that suppression of CH4 fluxes may have been the result of a 'salt effect' was ruled out. Both temperature and water table controlled the extent of CH4 flux suppression in acid rain impacted wetlands.

Sulfate reduction potential in SO42- treatments were found to be 10 times larger than in control plots, suggesting that long-term suppression of CH4 fluxes is the result of the formation of an enlarged population of competitively superior sulfate reducing bacteria.

SO42- concentrations were smaller in peat pore water from SO42- treatments than from controls. This is possibly the result of a stimulated SO42- reducing community scavenging available SO42-, thereby decreasing concentrations to below ambient levels. In northern peatlands (>50°) the effect of SO42- deposition at 1990 rates may have been sufficient to reduce emissions from these systems by around 15% annually. Globally, the effect of acid rain SO42- deposition may be sufficient to reduce CH4 emissions by as much as 22-28 Tg by 2030, which places this interaction within the same size category as many other components of the global CH4 budget that have received far greater attention.

Item Type: Thesis (PhD)
Copyright Holders: 2000 The Author
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Environment, Earth and Ecosystem Sciences
Item ID: 58051
Depositing User: ORO Import
Date Deposited: 30 Nov 2018 08:28
Last Modified: 05 Jul 2019 03:55
Share this page:

Download history for this item

These details should be considered as only a guide to the number of downloads performed manually. Algorithmic methods have been applied in an attempt to remove automated downloads from the displayed statistics but no guarantee can be made as to the accuracy of the figures.

Actions (login may be required)

Policies | Disclaimer

© The Open University   contact the OU