EIP Feature
Where Should I Plant My Hedge or Trees to ALSO Benefit Water Quality?
The tree planting season (Mid-November – March) is upon us and more opportunities than ever exist for landowners and community groups to Agri-environment Scientist, IRD Duhallow plant trees and hedges. Many farmers are receiving payments for planting trees and hedgerows through ACRES, the new national agri-environment scheme. The Native Tree Area Scheme has been recently opened which will allow farmers to plant 1ha of native trees on their land without a licence or 2ha if they are adjacent to a watercourse (with generous payments in return). Many dairy co-ops are also offering suppliers trees to plant on their farms, for example through the KERRY Evolve Programme. This provides a great opportunity to harness the multiple benefits of trees, including for water quality, provided they are planted in the right place! a ‘riparian buffer’. This involves Benefits of Trees Planting The Right Tree In The Right planting trees in the riparian The benefits of trees and hedges Place (riverbank) area. However, a are multiple for both farm and Knowing where water flows off buffer does not have to be in environment. Hedgerows were a field, allows us to strategically the immediate riverbank area. A once the boundaries of fields and target where trees and hedges hedgerow planted in the right place should be planted to intercept towns and prickly whitethorns and will also slow down water as it blackthorns created stock-proof overland flow. The EPA have moves through a field, long before barriers. Today, trees and hedges created Pollution Impact Potential it can ever get to the river! still provide important shelter (PIP) maps that are openly for livestock from wind, rain and available on www.catchments.ie. sun. These benefits will become These show areas at higher risk more pronounced as we move of runoff, as well as how water into the future and climate change (potentially carrying phosphates) intensifies. In addition, there is a moves off the land (known as body of evidence to support the nutrient flow pathways) and where importance of shelterbelts for soil it enters a watercourse. While health. this is an important resource that Hedges and trees provide helps us to put the right measure obvious benefits to biodiversity and in the right place, nutrient flow climate, through providing a habitat pathways can often be identified and sucking up carbon. But the on the ground, and farmers will key focus of this article will be the often know the path water takes importance of hedges and trees for as it moves through a field during water quality! heavy rainfall and where it enters Planting trees along an a watercourse. excessively eroding stretch of a Planting a hedgerow through one A riparian buffer strip river or stream is a nature-based of these nutrient flow pathways solution to stabilising riverbanks. will disrupt the flow of water and Preventing this excessive erosion allow the hedge to take up more will save the farmer from losing phosphates before they can get land and will reduce the amount to the watercourse. Alternatively, of sediment that enters the river, trees can be planted in a block carrying phosphates with it and at the point where the overland smothering insects and fish eggs. flow enters the watercourse. This Creating a ‘buffer’ involves is a very effective way to reduce planting in a place that will phosphate runoff. Phosphate is the intercept water as it moves dominant nutrient that runs off into over the land. This is because rivers in poorly draining areas. It is phosphates are transported also much more efficient in terms overland by water (unlike nitrates of land-use than planting an entire which leach through free-draining riparian strip, if water is running off Planting an eroding riverbank soil). A common buffer would be the field at specific points.
By MIKE O CONNOR
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DiscoverDuhallow@irdduhallow.com
Issue 102 November 17th, 2023
