Metla Project 3247
Regeneration of birch (Betula pubescens Ehrh.) stands in drained peatlands of Ostrobothnia
Duration: 1999-2003
Keywords: Betula pubescens, artificial regeneration, drainage, natural regeneration, peat nutrients, site preparation, under storey
Objectives
This work studied the effects of the density of a pubescent birch nurse crop and fertilization on the height growth of the spruce understorey, as well as the effects of equalizing the height of spruce seedling stand on its annual height growth on a drained peatland.
Results
The density of the birch nurse crop proved to have a major impact on the height growth of spruce undergrowth, on both the naturally established and the planted seedlings. Even the slight thinning of the nurse crop improved the seedlings growth. Fertilization alone did not substitute the effect of the nurse crop thinning and the greatest height growths were attained on the fertilized plots where the nurse crop had been removed. The height growth improved already during the first half of the 10-year study and was even greater during the second half of the study period. Due to height equalization the growth of the spruce seedlings first slowed down, but towards the end of the study period the height growth of the equalized and non-equalized spruce undergrowths were almost the same.
The results proved that the growth of the spruce seedlings was significantly greater on the managed than on the unmanaged areas. Still, the nurse crop is needed to shelter spruce seedlings during their early development against frost. The judicious timing of nurse crop management may enable the growth of pubescent birch pulpwood using a rotation of about 40 years on fertile peatlands and still maintain the spruce undergrowth in a vigorous state. The need of fertilization has to be judged according to nutritional stage of trees and the site fertility prior to managements.
Project leader:
Tillman-Sutela, Eila
The Finnish Forest Research Institute,
Muhos Research Unit,
Kirkkosaarentie 7, 91500 Muhos
Phone: +358 10 211 3719 Telefax: +358 10 211 3701
E-mail: eila.tillman@metla.fi
Other researchers:
Hytönen, Jyrki, KA (1999-2001), Moilanen, Mikko, MU (2000-01), Nurmi, Juha, KA (1999), Piiroinen, Marja-Leena, MU (2001), Päätalo, Marja-Leena, MU (2003)
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Updated 30.12.2006
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