Birches on peatlands
2001
Pikk, J. (Estonian Agricultural Univ., Tartu (Estonia). Inst. of Forest Industry)
Area of birch stands forms 30.2 per cent of our forestland. This area will be increased in near future because the cultivation of coniferous has decreased. Two species birches (Betula pendula and Betula pubescens) are able to form stands in Estonia. Silver Birch (B. pendula) has hybrids and numerous species of populations. On drained eu- and mesotrophic peat soil the stand of B. pendula has quit high productivity. The stand productivity will considerably improve after drainage peatlands with thin peat, where peat layer thickness decreases per year up to 1.5 cm transformation of fertile forest site types (Filipendula, Equisetum, drained swamp) occurs. It is necessary to thin more in decades from mixed stands. White birch has low growth intensity in older age and lowers quality of timber compared with Silver Birch. High step of thinning caused windfall of trees on peatlands. For forest regeneration on drained birch fens and swamps must be used more natural distribution of B. pendula if it is possible. There is no need to cultivate conifer on cut-owe peatland if the possibility of seed distribution of B. pendula occur from nearby areas. For afforestation cut-owe peatlands will be guarantee for normal water regime and fertilisation with phosphorus is needful
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