Juhani Päivänen

Männyn istutuksen ajankohta ojitetuilla avosoilla pääteinventoinnin tuloksia

Päivänen J. Männyn istutuksen ajankohta ojitetuilla avosoilla pääteinventoinnin tuloksia.

Tiivistelmä

This study is a sequel to papers previously published on the possibilities of extending the period of planting Scots pine (Pinus silvestris L.) on drained open peatlands over the entire growing season (Päivänen 1968, 1971), The study was carried out using the same plots as in the experiments described in the above-mentioned papers. This final investigation was carried out in order to find ou t whether the differences recorded in the previous studies had been leveled out or accentuated when 9—11 growing seasons in the field had elapsed since planting. As the smallest unit which the study was based on was a single row of young trees, the study must be considered as being completed by now. This is because the interactions between adjacent tree rows will become significant as soon as the crowns and root systems get closed. Mortality still increased by a few per cent units during the last 5—6 growing seasons. This increase, however, was of similar magnitude irrespective of the planting date. In the mean height of the trees, on the other hand, the differences caused by differences in the planting date were clearly visible in the final inventory (Figs. 1—3). The differences in height development had even become accentuated by the time of the final inventory, 9—11 growing seasons after planting. A clear correlation was observed, in the case of all experimental members, between the mean heights recorded in the final inventory and that carried out after the trees had spent four growing seasons in the field (Fig. 5). According to the results obtained the season-alness of planting work can be decreased on drained peatlands by extending the planting season of pine till the turn of the month between July and August. Plantings performed in the fall usually proved slightly less successful than those carried out in June and July. The nursery ought to be situated close to the areas to be planted since the handling and transportation of unrooted plants during the growing season must take place with extreme care.

Vastaanotettu 31.10.2017 Julkaistu 1.1.1975

Katselukerrat 454

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