Farm Ireland

Sunday 16 December 2018

Forest valued at €22,000/ha

Drumod Beg Wood is being considered for clear felling in four years' time.
Drumod Beg Wood is being considered for clear felling in four years' time.

Drumod Beg Wood was thinned for the first time in 2006 by removing one line in four. This was followed eight years later in 2014 with a second thinning.

An inventory was carried out before and after the second thinning. Results from this inventory indicated a yield class of 24 with a top height of 20.3m and a mean diameter at breast height (DBH) of 21.6cm. Note that top height is the height of the tree with the largest DBH in a 0.01ha plot.

Before thinning took place, stocking density was 1,200 stems per hectare, with an average volume 385m3/ha. Poorer quality trees were individually selected and removed during the second thinning. This resulted after thinning in a mean DBH of 25.2cm and an average volume of 350m3/ha. The stocking density was reduced from 1,200stems/ha before the second thinning took place to 822stems/ha after the operation.

The 35m3 removed during the second thinning provided 32pc pulpwood, 20pc stakewood, 30pc boxwood and 17pc sawlog. The proportion of each timber assortment in the overall mix is crucial as prices vary widely across the different timber assortments and will determine the overall price paid to the owner.

Buyers should quote a price per cubic metre or tonne for each of the timber categories being purchased. A higher proportion of more valuable sawlog will push prices up while a higher percentage of pulp will drive the overall price down.

As pulpwood tend to fetch lower prices, it is advisable to reduce haulage costs by selling locally. The pulpwood was sold to McCauley Wood Fuels in nearby Mohill and to the Masonite plant in Drumsna. The stakewood was sold to McHugh Timber Products in Killeshandra, while Murray's sawmill took all the boxwood and sawlog. This gave the three owners an average profit of €27 per tonne from 2013's operation.

With a clearfell envisaged at the age of 30, Western Forestry estimates that by then 8pc pulp, 20pc box and 72pc sawlog will be produced. It was estimated about 800stems/ha would remain, with a top height of 22.5m, a mean DBH of 27.8cm, and an individual tree volume of 0.59m3. This would give a volume of 470m3/ha.

Keeping in mind my earlier remarks on timber assortments, it is interesting to compare the timber assortments at clearfell with the second thinning stage.

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The proportion of pulp has been reduced dramatically while the proportion of sawlog has increased significantly. This gives this 30-year-old forest an overall estimated value of €22,000/ha, or €733/ha over 30 years.

Indo Farming