Catchment News

Mending a ragged blanket bog: room for improvement?

Raymond Flynn and Francis Mackin from Queens University Belfast tell us about how their research is helping us understand the relationship between ecology and hydrology in Ireland’s blanket bogs, and how their search for intact blanket bogs had startling results…

It will come as no surprise to some readers of the Catchments Newsletter that many of Ireland’s wetlands are in a bad way. Mechanised peat harvesting has resulted in the loss of extensive areas of bogland over the last 60 years. So much so that once common habitats, such as the active raised bog (ARB), which supports peat accumulating plant communities, have now become rare, with coverage estimated at less than one percent of its original area. What’s more these activities continue, even in many protected areas.

The on-going damage to Irish peatlands has motivated the European Commission to raise the possibility of imposing annual €9,000,000 fines on Ireland to force us to address this issue. The particularly acute situation of raised bogs has prioritised their assessment, done by pulling together botanical and hydrological knowledge accumulated over the past 30 years. This information has allowed National Parks and Wildlife Service (NPWS) to develop a scientific basis for raised bog conservation and restoration programmes for each site in Ireland’s network of raised bog special areas of conservation (SAC) and national heritage areas (NHAs). These programmes now form part of Ireland’s National Peatland Management Plan.

Progress made by NPWS has been accompanied by a wider recognition of the need for peatland conservation and restoration. On the coattails of the NPWS survey, raised bog conservation and restoration has received further boosts through the EU-funded Living Bog Project, and smaller community-based initiatives, such as those at Abbeyleix, Co. Laois, and Mount Allen, Co. Roscommon. In all cases, scientific knowledge and expertise help identify causes of habitat loss, aiming to reverse year on year trends, and although the situation is far from ideal, there have been some successes, such as Lisnagerragh, Co. Galway where restoration measures have resulted in the area containing ARB more than doubling between surveys completed in 1994 and those carried out in 2012.

But of course, raised bogs form only part of the equation. What about other peatland types? Research into fen ecohydrology has been reasonably detailed, with findings from elsewhere allowing Irish researchers to better understand fen dependence on hydrology. As a result, we have a reasonable understanding of how water supports fen ecosystems.

By contrast, the situation with blanket bogs is not so rosy. Although there is a widespread consensus that water forms a crucial supporting element for blanket bog ecosystems, a review of the scientific literature reveals that almost all hydrological research focuses on sites that have been damaged, often through burning or overgrazing.

The motivation for most blanket bog hydrological research is the development of restoration plans. But to what? In the case of severely damaged areas, where vegetation may be thin to absent, colonising the surface with plant cover is considered a success; but is that really good enough? Shouldn’t we be aiming to bring back the blanket bog that was there in the first place, and all the benefits/ecosystem services this entails?

One of the aims of the EPA-funded research project Towards the Quantification of Blanket Bog Ecosystem Services (QUBBES), is to better understand the relationship between blanket bog ecology and hydrology in intact blanket bog catchments. To this end, QUBBES researchers undertook a survey of blanket bog catchments, searching for those areas where there was no evidence of physical disturbance, including drainage, peat cutting, burning, overgrazing, forestry or wind turbine developments.

The results proved startling. Of the 341 candidate catchments considered least disturbed, and thus included in the survey, 11 showed no sign of physical disturbance. Even more surprisingly, of the four sites considered most suitable as undamaged sites, all displayed evidence of physical disturbance, including burning, overgrazing and/or drainage, when inspected on the ground.

Findings underscored the need to abandon the idea that large areas of Irish blanket bog remain intact; scientific data clearly suggest otherwise.

Looking at this another way, the results highlight an even greater need to understand ecohydrological processes in these if appropriate restoration targets are to be established. By following this approach, and combining lessons learnt in developing raised bog conservation plans, realistic restoration targets may be established, and scarce resources most effectively applied to maximise benefits to society and the wider environment.

Raymond Flynn and Francis Mackin, School of the Natural and Built Environment, Queen’s University Belfast.

Learn more:

www.qub.ac.uk/schools/NBE/Research/ResearchCentres/qubbes/