Ackzell L, Elfving B, Lindgren D
Occurrence of Naturally Regenerated and Planted Main Crop Plants in Plantations in Boreal Sweden
Forest Ecology and Management: 1994 65:105-113
In all plantations established in 1983 by a company operating in northern Sweden, representative fixed Plots were identified where all Planted seedlings were mapped. After ten growing seasons (1992), 282 fixed plots on 97 clear-felled, scarified and planted sites were monitored. For Pinus contorta Dougl., 80% of the planted seedlings were alive, while for Pinus sylvestris L. and Picea abies (L) Karst., survival was 66%. Living planted seedlings exceeded 1600 ha-1 (fully stocked) on half of the plots, but were below 1000 on 20% of the plots. Naturally regenerated seedlings were classified in terms of their potential to serve as main crop plants. If all healthy naturally regenerated seedlings growing more than 0. 6 m apart are accepted as main crop plants, 99% of the plots were fully stocked. Full stocking was more often achieved by naturally regenerated seedlings alone than by planted seedlings alone. Of all naturally regenerated main crop plants, 55% were conifers. Naturally regenerated conifer main crop plants exceeded 1600 ha-1 on 20% of the plots. The occurrence of naturally regenerated conifers was positively correlated with low altitude and proximity to seed source. Planted seedlings were taller than natural. The results demonstrate that natural regeneration is important for artificially regenerated forests.
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