Ackzell L, Lindgren D
Some Genetic-Aspects of Human Intervention in Forest Regeneration - Considerations Based on Examples from an Experiment in Northern Sweden
Forestry: 1994 67:133-148
Some genetic consequences of forest regeneration methods are discussed based on results from an 11-year-old experiment with Scots pine in northern Sweden. The experiment comprises two environments (seed-trees and clear-felling), two regeneration methods (planting and sowing) and four seed sources (local seeds from the seed trees, northern stand seeds and two seed orchard crops). Seed source was important compared with environment and regeneration method for the occurrence of empty cultivation quadrats (2 x 2 m). In relative terms it was less important for growth. There was no indication that progenies of the local trees were best suited for the locality. There was no evident positive effect of the higher selection caused by higher.mortality and release thinning in some entries compared with others. Hence, a higher selection after sowing than after planting could not be shown to have positive effects. The variance between half sib families was a small share of the total variance, and thus the number of parents is probably unimportant for variance of tree height or seedling survival in a forest. Progenies from the seed orchards grew fast, but the mortality was higher than for the stand progenies. There was no significant genotype X environment interaction. There was a significant genotype x method interaction, seed orchard progeny were better for sowing than for planting.
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