Restoration effects on water table depths and CO2 fluxes from climatically marginal blanket bog

Abstract

This study aimed to measure the effects of ecological restoration on blanket peat water table depths and CO2 fluxes. The flux of CO2 and water table depths were measured on eight sites for five years. Results suggest that sites with revegetation alongside slope stabilisation have the highest rates of photosynthesis and are the largest net (daylight hours) sinks of CO2. Bare sites are the largest net sources of CO2 and have the deepest water table depths. Sites with gully wall stabilisation are between 5-8 times more likely to be net CO2 sinks than the bare sites. Revegetation without gully flow blocking using plastic dams does not have a large effect on water table depths in and around the gullies investigated whereas a blocked gully has water table depths comparable to a naturally revegetating gully. A ten centimetre lowering in water table depth decreases the probability of observing a net CO2 sink, on a given site, by up to 30%. The most important conclusion of this research was that restoration interventions are effective at increasing the likelihood of net CO2 sink behaviour and raising water tables on degraded, climatically marginal blanket bog.