Evaluating Different Wetland Creation Approaches for Irish Cutaway Peatlands Using Water Chemical Analysis

Abstract

By 2030, 75,000 ha of raised bog owned by Ireland’s largest peat producer, Bord na Mona, are expected to be exhausted. In an effort to rehabilitate Irish cutaway peatlands to maximise their conservation value, large areas have been converted to wetlands using three alternative approaches: total peat removal (TPR), partial peat removal (PPR), and simple rewetting (SR). This paper assesses the success, to date, of the three wetland creation approaches using hydrochemistry as a measure of restoration success and identifies the key variables influencing hydrochemistry in the created wetlands. Chemical analysis suggests major differences between the TPR and SR wetlands while the PPR wetlands exhibited intermediate characteristics. Additionally, principal component analysis highlighted nitrite, conductivity, turbidity, chlorophyll-a, colour, and soluble reactive phosphorus as important hydrochemical factors determining differences among the three wetland creation approaches. This research shows that wetlands underlain by peaty substrates (PPR and SR) may take longer than 10 years to stabilise hydrochemically compared to those wetlands underlain by solely alkaline sediments (TPR) which stabilise quickly. Although wetland ecosystem development may be slower in the PPR and SR wetlands they hold the greatest potential to develop peat forming habitats. Wetland creation represents a viable and valuable post-harvesting land-uses option for cutaway peatlands.