Title: Ecosystem services provided by turloughs
Researchers: Fabio Delle Grazie, Prof. Laurence Gill, Dr Owen Naughton
Turloughs are topographic depressions in karst, which are intermittently flooded on an annual cycle via groundwater sources and have substrate and/or communities characteristic of wetlands. The WFD requires the protection of the water-bodies supporting Ground Water Dependent Terrestrial Ecosystems GWDTEs) and so this requires knowledge of whether the status of the groundwater body is impacting on the functioning of the GWDTE and if so, what measures can be introduced to mitigate it.
Turloughs provide a habitat for many protected flora and fauna species and are designated a Priority Habitat in Annex 1 of the EU Habitats Directive (92/43/EEC) as well as GWDTEs under the Water Framework Directive (WFD). There are an estimated 483 turloughs in Ireland. Indeed, the majority of turloughs globally occur within Ireland and so the State has an international obligation to protect them. Hydrology is the primary driver of these unique ecosystems and so a rigorous understanding of the hydrological regime is required in order to assess their conservation and future sustainability.
The development of chemical and quantitative status tests for GWDTEs (including turloughs) within the context of groundwater body classification under the WFD and associated Groundwater Directive was carried out by Kimberly and Coxon (2013). An alternative way of evaluating the status of a GWDTE is the concept of defining the ecosystem service provided by the wetland.
- Identify and quantify the ecosystem services associated with turloughs, particularly in relation to the need for habitat conservation in the face of external pressures associated with agriculture, road drainage schemes, water supply and wastewater disposal.
- Evaluate the ecosystem services of turloughs and develop a framework that outlines the methodology and actions to be undertaken when attempting to assess damage from external pressures.
- Quantify the ecosystem functions responsible for producing terrestrial hydrologic and climatic services, as well as intrinsic biodiversity services
- Use this context to lay out a blueprint for a more detailed ecosystem service assessment.
The ecosystem services will be quantified in appropriate units (ecological, socio-cultural and economic indicators as well as monetary values), based on actual or potential sustainable use levels. Available data and field studies will be used to assess the hydrological conditions necessary to sustain the biodiversity of vegetation as well as to better understand the connections between hydrology and biogeochemical cycles. Field studies will be carried out at a minimum of six different turloughs to capture a range of different hydrological types: from rapid filling and emptying to slow single peak duration. Soil sampling by cores as well as closed chamber gas measurements will be carried out to estimate carbon sequestration and emissions. Subsequent modelling will then be used to predict the impacts of changes in land use, hydrological regime and climate change on greenhouse gas emissions from organic soil. Once the ecosystem services of the turloughs have been defined a series of test cases will be compared to assess real or potential damage. These will mainly focus on road schemes through karst areas, in collaboration with the TII, for both existing schemes (e.g. Gort bypass in South Galway) as well as proposed schemes (e.g. N5 realignment through Roscommon).