Budget for a €2,500/ha reforestation cost after clearfelling mature forest

William Merivale

August 13 2013 04:03 AM

Unless they have made the move towards continuous cover forestry, most owners and certainly those of even-aged plantations with one or two species will expect to clearfell the crop once it reaches maturity.

Economic maturity for forests planted on productive soils may well be from 30 to 35 years of age and, in some cases, even earlier.

Over the last few months I've been involved in two such clearfells and will share my experiences from the first of those.

The area in question is about ten hectares (25 acres) and was the most mature sub-compartment in a larger area of woodland. The felled area was 90pc Sitka spruce, 10pc larch, 44 years old and on top of an exposed hill. At yield class 18, the crop could have grown on for a few more years, but on this exposed site, some stems had already started to blow.

The crop had been well thinned in the past and the final harvest produced 4,325 tonnes, of which 64pc was sawlog, 24pc palletwood and the remaining 12pc mostly pulp, with a couple of loads of stakewood.

The felling licence stipulated that restocking species should include Sitka spruce and Douglas fir instead of larch. While the owner's objectives for the site remain principally commercial, his aim is to diversify and restructure as much of the woodland as possible.

Accordingly, while Sitka made up 66pc of the restocking, the other 34pc included Douglas fir, western red cedar, Scots pine, oak and birch. A few common alder were also planted in a wet corner.

The Scots pine was chosen to enhance an area on some of the highest ground where some retained specimens are still in good health.

They were planted in mixture with oak (three rows by three rows), and the balance of the oak was planted in clumps with the birch. The site is a prominent local landmark, so hopefully this approach will be seen to have enhanced the landscape in the years to come.

EXPERIMENT

Admittedly, the western red cedar is an experiment as it is not widely grown in Ireland.

However, it produces excellent construction timber as it is light, strong and, while it doesn't take preservative treatment well, is naturally very durable.

Thinnings make ideal fencing material – the logs can be split easily rather than sawn, and untreated they still last for years. They were planted in mixture with the Douglas fir and time will tell how they fare.

The brash, lop and top was windrowed with the rows 12m apart, making up most of the retained deadwood on the site, an important component for biodiversity. Standing deadwood, where it exists, should also be retained but in this instance there were no standing dead trees on the site.

Fortunately, fencing was not an issue as most of the boundaries are internal and the fence along the third-party boundary was, for the most part, still stockproof. However, rabbits are quite a problem so all the broadleaves are protected with plastic spiral guards.

Replanting commenced at the end of March and not long after the work finished we feared that the spell of cold, dry weather with that strong easterly wind would spell disaster as the site is exposed and dry.

There was a brief respite with a small amount of rainfall, followed by the exceptionally warm and dry six weeks in June and July. But, remarkably, the young trees have fared well, with very few losses so far of Sitka, Douglas and cedar, though the oak and Scots pine have not done so well, with losses of over 50pc in both species.

All the conifers were pre-treated against pine weevil. This was achieved at the nursery by dipping plants in a solution containing the pesticide Cypermethrin which gives protection for four-to-six months. So far, no weevils have been found.

Beating up will take place during the winter months and prior to that some weed control will be necessary, especially of briar where patches are starting to take over.

The table (below left) gives a summary of the reforestation costs, including VAT incurred to date.

By the time weed control, beating up, any further pine weevil treatment and costs of supervision are accounted for, it will probably be safe to budget on a total reforestation cost of about €2,500/ha.

William Merivale is national secretary of PEFC Ireland and a forestry consultant based in Cork. Email: william@cjandco.net