2.5.1. Case Study 5: effects of harvesting on genetic
variation of Pinus strobus in Ontario
Genetic variation was assessed in two mature Pinus
strobus forests in Ontario, Canada at 13 SSR (microsatellite)
gene loci prior to and after partial cutting
aimed at promoting natural regeneration. Measures of
genetic variation referring to the preharvest and postharvest
situation are described in Table 3.
Harvesting resulted in a loss of allelic multiplicity
as shown by the reduced total number of observed
alleles in the postharvest situation. Most of the lost
alleles were rare (P < 0.05) in the preharvest stands.
The observed and expected heterozygosities were only
slightly reduced (1–5%). Similar results were previously
obtained based on variation at isozyme gene
loci.