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Action 12. Overgrazing

The problem of overgrazing by sheep in blanket bogs in the west of Ireland was first highlighted in the early 1990's with reported damage to important game fisheries due to excessive amounts of peat silt from eroding peatlands (Huand & O'Connell 1992). Teagasc estimate that around 20% of the upland area (0.3million ha) may be affected by soil erosion to varying degrees. Overgrazing by sheep is one of the principal contributing factors, and this problem has arisen as a direct result of EU-funded incentives.

Overgrazing on blanket bog has resulted in a decrease in vegetation cover, a depletion of bog species, invasion by species alien to the bog habitat and erosion of peat surfaces (Bleasdale 1995, MacGowan & Doyle 1996 and 1997, and McKee et al 1998). The loss of characteristic and rare flora, such as heather, sedges and mosses, deprive wildlife of food and cover and numbers of fauna may also therefore be affected (Douglas 1998). 52 existing blanket bog NHAs have been degraded and sites are being lost without ever having been surveyed. In addition, eroded peat particles are washed into rivers and streams, choking up spawning beds. Acutely degraded blanket bog systems can be found in Mayo, West Galway and Kerry, areas which overlap with the main distribution of blanket bog NHAs and SACs (EPA 2000).

Geeling & Van Gestel (1997) estimated that as much as 27% of upland south Mayo and Connemara were extremely degraded (i.e. 40% bare peat). The Department of Agriculture are currently involved in assessing commonage areas to estimate the damage and to suggest optimum stocking densities for livestock. Measures to alleviate serious overgrazing problems will then be introduced via REPS (DOA 2000). An EU Life-funded project focusing on Cuilcagh Mountain Blanket Bog in Co. Fermanagh set about devising a grazing regime which is compatible with blanket bog conservation. The site was suffering badly from overgrazing until the agri-environment regime introduced a seasonal ban on sheep grazing during the winter months and a limit on stocking density to 2 ewe/ha. However, this reduction proved not to be enough to allow the degraded bog areas to recover. The land managers set up demonstration plots to experiment with different stocking levels. Through this and other experiments in the area it became clear that an average of 0.5 ewe/ha was the allowable limit (Raeymaekers 2000).

In the most badly damaged blanket bogs of the west of Ireland, initially a complete ban on grazing is required, which can then be followed by a low level of grazing once vegetation regeneration occurs (MacGowan 2000).

The recommended stocking density for sheep on bogs in Britain is even lower at rates of 0.25 to 0.37 ewe/ha in summer only (Rowell & Clarke 1988).

General Objective
To halt the degradation of blanket bogs from overgrazing and to restore bog vegetation to degraded areas.

IPCC have campaigned on the issue of overgrazing to Dúchas and the European Commission to have measures introduced to halt the degradation of conservation worthy blanket bogs. We monitor the effects of overgrazing on NHAs.

Actions
3.12.1 The Department of Agriculture should complete the Commonage Assessment Survey without delay and establish optimum stocking densities for overgrazed areas.

3.12.2 Department of Agriculture in conjunction with Dúchas should implement Commonage Framework Plans within blanket bog areas which will enforce strict guidelines on agricultural practices.

3.12.3 All areas of blanket bog should be subject to similar stocking densities as determined by the Commonage Assessment Survey.

3.12.4 Dúchas should undertake further research on restoration measures for overgrazed blanket bogs.

3.12.5 Dúchas and the Department of Agriculture should introduce guidelines and incentives for farmers to restore degraded blanket bog habitats to include training and demonstration projects.