Metsänparannustoimenpiteiden vaikutuksesta suoekosysteemin kasvibiomassaan ja perustuotantoon
Reinikainen A. Metsänparannustoimenpiteiden vaikutuksesta suoekosysteemin kasvibiomassaan ja perustuotantoon.
Tiivistelmä
On the basis of case material collected in the studies of Kosonen (1976), Ouni (1977), Vasander (1981a) and Solmari (unpubl.) and with references to Paavilainen's (1980) material a review was made on the primary production patterns of mires ameliorated for forestry (Fig. 1). The available data represented poorly the variation of mire types, fertility classes, improvements and succession time. As first examples from c. 5,3 million hectares of ameliorated mires in Finland the results were published. The total biomass and tree-biomass increased parallelly being dependent on site type, original tree stand, treatment and time (Fig. 1, Table 1). The biomass of lower vegetation layers developed more irregularly. The field layer with changing species composition maintained its biomass better than the ground layer, which suffered most from the decreasing moisture and increasing canopy shadow. Along all the succession the proportions of lower vegetation in biomass decreased steeply. In 40—60 years the biomass distribution reached appr. the state of pine forests on mineral soils. Higher biomass of field layer was a reminder of mire succession. Above ground production (Fig. 1, Table 1) changed less than the biomass, but mainly increased. The total efficiency of the community was after drainage 103— 187 %, and after additional NPK fertilization 150— 230 %, of that in virgin mire type. The distribution of primary production changed so that the proportion of tree biomass increased. However, the amount of stem growth did not increase in the same degree.
Vastaanotettu 31.10.2017 Julkaistu 1.1.1981
Katselukerrat 1120
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