Chapter 2 - Threats to the Bog and Project Actions

Video produced by Tailored Films.

Please visit www.raisedbogrestoration.ie for more information.

Raised bogs are most common in the central lowlands of Ireland. At one time, they covered three hundred and ten thousand hectares. Over the last 200 years, about 92% of Ireland's raised bogs have been lost.

A wet bog is a happy bog. Any action that drains them or dries them out damages their habitat. Human activity is largely responsible for this, mainly through the commercial harvesting of peat for domestic use and to generate electricity. To a lesser extent, drainage, and afforestation, or the planting of trees, have damaged our bogs.

During the 20th century, the commercial harvesting of peat was very common and created a significant amount of rural employment. This is the single biggest threat to raised bog habitat and has led to widespread and sometimes total loss of our bogs. Coillte and the National Parks and Wildlife Service have taken an active role in raising awareness about the importance of conserving bogs, and the implications of exploiting them. Information stations have been placed along the board walk to communicate this to the public.

Along with peat harvesting, drainage has also caused immense damage to bogs. For many years, ditches were dug, which drained the water. A bog needs to be in waterlogged conditions in order to produce peat, so these ditches dried out the bog and almost completely destroyed them. One of Coillte's most important objectives is to restore the natural wetness of the bog so that it is able to produce peat. To do this, the drains need to be blocked. There are two methods which the project team have used to block drains, one is to install peat dams using machinery. In areas where the bogland is too wet for machinery to travel, plastic dams are installed manually.

Afforestation, or the planting of trees, have also damaged bogs, but on a much smaller scale. Afforestation was part of a government policy to create employment. About 2% of Ireland's raised bogs were planted with trees. Most of these afforested areas are owned by Coillte. Coillte and the National Parks and Wildlife Service have worked hard to remove plantation forests and re-wet dry areas.

Once the actions are carried out, the water levels and vegetation need to be monitored and recorded.

In order for a bog to be actively growing, the water levels need to be within 10 cm of the surface all year round.

As part of the project, dipwells were installed to compare water levels before and after tree removal. Before the trees were felled, water levels were at their lowest. Results have shown a very dramatic increase in water table levels within a year of tree removal. These dipwells are read on a monthly basis to record water levels.

Aside from human destruction, bogs face many other threats. Animal trespass is one of those. If a large number of animals graze on a bog, it can lead to overgrazing and damage of the bog's vegetation. In order to combat this problem, Coillte have fenced off sites where animal trespass is problematic.

Bogs are also at risk from fires. Fires cause damage to bog vegetation, which eliminates decades of Bog regeneration. Coillte install fire breaks around the perimeter of sites to help prevent fire damage.

Invasive species like lodgepole pine, laurel and rhododendron also slow down bog formation. Dense infestation of species like these take over certain areas of bogland and stop native bog vegetation from growing. The continuous growth of these invasive plants, as well as native plants like birch and willow, also dry out the bog because of their water absorption. Coillte have taken an active role in removing and controlling regeneration of these species on high raised bog.

Over the course of the project, there has been a huge improvement in the quality of raised bog habitat. It was found that once the trees were removed, and the drains blocked, the water levels rose quite rapidly, allowing the moss to grow and reclaim the bog. We can see this not only in the immediate restoration area, but the entire surrounding bog. The restoration area is the start of an ever increasing expanse of bog regeneration.