The effects of bog restoration in formerly afforested peatlands on water quality and aquatic carbon fluxes

Student thesis: Doctoral ThesisDoctor of Philosophy (awarded by OU/Aberdeen)

Abstract

The restoration of drained, afforested blanket bogs (forest-to-bog restoration) is an increasing management practice, due to recognition of both the nature conservation and carbon sequestration services provided by peatlands. Forest-to-bog restoration involves conifer felling (and harvesting) along with blocking of forestry drains. Research from conifer felling and drain blocking on open peatlands shows significant effects on pore- and stream- water quality, when practised separately. However, there is very little knowledge of the combination of both these practices in forest-to-bog restoration.
This research investigated the effects of forest-to-bog restoration on pore-, surface-, stream- and river water quality in the short-term (0-1) years post-restoration, where the effects of restoration are disturbance-related. We also investigated restoration progress across a chronosequence of restoration sites using pore- and surface-water chemistry.
Our results showed significant increases in DOC, phosphate, K and NH4+ (2-99 fold) in pore- and surface- water in the first year post-restoration, which may have implications for the recovery of bog vegetation. In streams significant increases in Fe (1.5 fold) and phosphate (4.4 fold) were found, with no significant impacts on concentrations in rivers or pass rates for drinking water or WFD standards. We also found no significant effects on aquatic carbon exports. However, as more restoration is carried out within the catchments and the proportion felled increases, greater impacts on streams and rivers may be observed. From our results, we recommend felling small percentages (3-23%) of stream and river catchments and the use of drain blocking and silt traps to retain sediment.
We observed progress in recovery towards bog conditions across a chronosequence of restoration sites (aged 0-17 years); incomplete recovery of WTD and elevated NH4+ in porewater appeared the main barriers to restoration. Therefore, enhancements such as brash and needle removal and plough furrow blocking may be able to accelerate restoration.
Date of Award19 Jul 2017
Original languageEnglish
Awarding Institution
  • The University of Edinburgh
SupervisorRoxane Andersen (Supervisor), Mark Taggart (Supervisor), Mark Hancock (Supervisor) & Ruth Robinson (Supervisor)

Cite this

The effects of bog restoration in formerly afforested peatlands on water quality and aquatic carbon fluxes
Gaffney, P. P. J. (Author). 19 Jul 2017

Student thesis: Doctoral ThesisDoctor of Philosophy (awarded by OU/Aberdeen)