Timo Penttilä , Mikko Moilanen

Lannoituksen vaikutus hieskoivikoiden kasvuun ja ravinnetilaan ojitetuilla turvemailla Pohjois-Suomessa

Penttilä T., Moilanen M. Lannoituksen vaikutus hieskoivikoiden kasvuun ja ravinnetilaan ojitetuilla turvemailla Pohjois-Suomessa.

Tiivistelmä

The effects of fertilization and refertilization on the growth of pubescent birch (Betula pubescens) stands growing on drained peatlands in northern Finland were studied in eight field experiments. The treatments were: (i) control with no fertilization, (ii) fertilization with nitrogen (N), (iii) fertilization with phosphorus and potassium (PK), and (iv) fertilization with nitrogen, phosphorus, and potassium (NPK). The sites represented four different mesotrophic to eutrophic site types with stand median heights ranging from 7 m to 13 m. Tree growth was monitored at stand level during periods of five to eleven years following the setting up of the experiments and during periods of 4 to 7 years following the repetition of the treatments in 1985. At the end of the second period, sun-exposed leaves were sampled from two stands in August 1990 for the purpose of conducting foliar nutrient analyses. The first-time fertilization treatments did not affect tree growth on any of the site types. Following the repetition of the treatments, the stands responded positively to NPK or PK fertilization on all site types except on the shallow-peated herb-rich peatland forest. There was no response to mere N-fertilization on any of the site types. The growth responses observed were weaker than those reported for Scots pine in similar climatic conditions. Key words: Betula pubescens, foliar nutrients, growth responses, nitrogen, peatland, phosphorus, potassium

Avainsanat
nitrogen; phosphorus; potassium; peatland; Foliar nutrients; Betula pubescens; growth responses

Vastaanotettu 31.10.2017 Julkaistu 1.1.1997

Katselukerrat 1521

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