Alder Improvement Programme

Alnus glutinosa is a native species, also known as common alder, black alder or European alder. It is widespread across all of Europe from mid-Scandinavia to the Mediterranean countries, including northern Morocco and Algeria.  Alders can grow on a wide range of soil types as well as on soils with varying nutrient status. They can also be found on soils ranging in values between 4.2 and 7.5 pH. Alders are tolerant of sites prone to periodic flooding as well as having the ability to adapt and live in habitats with high water tables. The characteristics of black alder wood make it very suitable for many different uses.  Apart from alder making very good firewood its fibre is ideal for paper making and good quality alder is an excellent timber for joinery as a solid wood or veneer. 

In Ireland, alder represents 4.9% of the forest area and 9.7% of the total broadleaf area (National Forest Inventory). In response to the increased demand for seed and plants especially during the years 1997 to 2007 an alder working group was set up in 2004 by CoFoRD. The group consisted of interested parties from commercial nurseries, regulatory personnel, foresters, researchers and forestry advisers. A nationwide survey was conducted by the group in 2004 to identify healthy, vigorous and quality plantations.  As a result an Alder Improvement Programme was initiated in 2005 with the aim of providing genetically improved alder tree germplasm for deployment in farm forestry. Eighty-eighty plus trees were selected from seventeen sites throughout the country.

Seed was collected from the plus trees, germinated and plants used to establish three progeny field trials, Cavan and Clare in 2008 and Sligo in 2009.

Also:

• Scion material was collected from the plus trees for grafting
• A clonal gene bank was established at Teagasc Oak Park, Co Carlow
• An indoor alder clonal seed orchard was established in 2009 at Teagasc Kinsealy and later relocated to Teagasc Ashtown
• The indoor alder seed orchard received ‘qualified’ status in 2013

The indoor alder clonal seed orchard is located in a new, purpose-built polytunnel at Teagasc Ashtown Food Research Centre, Dublin 15. It is hoped that the indoor seed orchard will produce sufficient seed to establish progeny trials to assess the value of the trees as parents.

The existing field trials established in Cavan, Clare and Sligo were assessed and growth data recorded in 2008, 2009, 2010, 2015, 2017 and the Cavan trial again in 2020. These trials will continue to be assessed and growth data recorded on a regular basis.

The objectives of this breeding work are to:

• Identify poorer performing parents and rogue from the seed orchard
• To estimate their respective breeding values
• To establish new tested clonal seed orchards composed of the best parents following evaluation of the progeny trials
• Provide genetically improved tree germplasm for deployment in farm forestry