The age of black pine (Pinus nigra Arn. ssp. salzmannii (Dunal) Franco) mother trees has no effect on seed germination and on offspring seedling performance

Abstract

Key message: We sampled Pinus nigra cones in 29 trees in an age range of 90 to 725 years. The mother tree age did not significantly influence the pinecone or pine seed size, seed germination capacity, or plant size or vigor displayed during the first year of growth in the nursery. Context: Pinus nigra Arn. ssp. salzmannii is a long-lived Mediterranean species, with millenary trees residing in an old-growth forest in the Cazorla Mountain Range in SE Spain which is home to the oldest known trees in the Iberian Peninsula. Aims: This study aimed to assess how the mother tree age in Pinus nigra influences seed viability, germination capacity, and the seedling survival and growth during the first year under nursery conditions. Methods: Twenty-nine trees aged 90 to 725 years were selected and 60 cones were harvested per tree to study the cone characteristics (size and weight), seed viability, and germination capacity in relation to the mother tree age. Eighty germinated seeds per tree were transferred to the nursery and seedling survival and growth were measured after the first growing season. Results: Significant between-tree differences were detected for cone characteristics (cone and seed weight, number of seeds per cone), as well as for germination capacity. Notably, however, the mother tree age did not significantly influence the aforementioned parameters. Conclusion: Forest management and regeneration practices of Pinus nigra should take into account that trees of this species up to at least 725 years old produce seeds with a fairly high reproductive capacity.