Volume production patterns in six downy birch stands in Ireland.

  • Maarten Nieuwenhuis Department of Crop Science, Horticulture and Forestry, University College Dublin, Belfield, Dublin 4.
  • Frank Barrett Centroid Solutions Ltd., 3 Wellington Park, Malone Road, Belfast, BT9 6D.
Keywords: Betula pubescens (Ehrh.), downy birch, mean annual increment, mean periodic increment, volume production patterns, tree ring analysis.

Abstract

Six well-stocked, unthinned downy birch (Betula pubescens (Ehrh.)) stands in Cos. Wexford, Laois, Wicklow, Offaly and Westmeath were selected for study. A total of 100 sample trees were felled at the six sites. Tree ring data were collected from a total of 1333 tree discs. Using the ring data the historic growth patterns of the six stands were reconstructed, examined and analysed. Local volume equations (volume/basal area lines) expressing the relationship between sample tree over-bark volume (to tip) and basal area were fit to data from two 0.04 ha plots at each site. These were used to determine per ha over-bark standing volume estimates. For well-stocked, unthinned even-aged stands of downy birch the period of maximum radial growth occurred between the ages of 5 and 20 years. The fastest growing tree achieved a diameter of 25 cm in 32 years. Maximum height growth occurred before the trees were twenty years old; fast growing trees achieved a height growth of more than 1 m yr-1 during this period. The results showed that a well-stocked, unthinned downy birch stand could achieve a standing volume of 203 m3 ha-1 in 42 years. Comparison with Forestry Commission yield models showed that stands of downy birch in Ireland may achieve a potenti al yield class of 8 and, given the appropriate thinning regime, total recovered volume production could possibly be raised to that equivalent with yield class 10.
Published
2001-11-01
How to Cite
Nieuwenhuis, M. and Barrett, F. (2001) “Volume production patterns in six downy birch stands in Ireland.”, Irish Forestry. Available at: https://journal.societyofirishforesters.ie/index.php/forestry/article/view/9909 (Accessed: 28March2024).
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Articles

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