Genetic consequences of harvest in a mature second-growth stand of black walnut (Juglans nigra L.)

Rodney L. Robichaud , Jeffery C. Glaubitz , Olin E. Rhodes , Keith Woeste

This study investigated the short-term changes in neutral genetic variation that would occur if a mature, second-growth, black walnut (Juglans nigra L.) stand was harvested following either a diameter-limited or value-limited cutting regime. * This research tested whether or not the neutral genetic variation within a natural stand of black walnut was disproportionately distributed within the larger or more valuable cohort of trees. To test this hypothesis a complete census of 278 trees from a black walnut stand in Indiana was genotyped using 12 highly polymorphic microsatellites. * Two types of simulated harvests were performed: (1) diameter-limit cuts, where every tree above a given diameter was removed; and (2) selective harvests based on value, where subsets of the most valuable trees were removed. Allelic diversity of the remaining population after each simulated harvest was compared to a corresponding distribution of outcomes from 10000 random harvests of equal intensity. * None of the simulated harvests resulted in a reduction of allelic diversity significantly greater than that expected under random harvest, indicating that the allelic diversity of the population was evenly distributed across the entire population. * These results indicated that typical harvest scenarios do not per se lead to loss of allelic diversity among trees for this species.

Mots clés: forest genetics; allelic richness; genetic diversity; diameter-limit; high grading

Domaines: Sylviculture, foresterie

Rodney L. Robichaud, Jeffery C. Glaubitz, Olin E. Rhodes, Keith Woeste. Genetic consequences of harvest in a mature second-growth stand of black walnut (Juglans nigra L.). Annals of Forest Science, 2010, 67 (7), ⟨10.1051/forest/2010027⟩. ⟨hal-00883611⟩