Download (PDF 376 KB): https://research.fs.usda.gov/download/treesearch/28392.pdf
Abstract
During 1989 in east-central San Luis Obispo County, California, we studied the relationship of valley oak (
Quercus lobata) and blue oak (
Q. douglasii) acorn planting depth and number of acorns per planting site to acorn depredation, seedling emergence, survival, and height. Acorns were planted at three depths (1.3, 5.1, and 10.2 cm) at each of 960 planting sites with one or three acorns per site. Animal depredation of acorns was significantly (P < 0.05) greater for valley oak and seedling emergence and survival were significantly higher for blue oak. depredation of valley oak acorns decreased significantly with deeper planting; depredation of blue oak acorns was significantly greater at the most shallow planting depth than at the two deeper depths where it was about the same. although between depth differences were not significant (
P > 0.05), seedling emergence and survival of valley oak seedlings at the two deepest planting depths were better and almost identical. Conversely, blue oak seedling emergence and survival were significantly better at the two most shallow planting depths, and there was a strong, but insignificant, trend toward the best blue oak emergence and survival at the 5.1-cm depth. Regardless of planting depth, planting several acorns per planting site significantly decreased depredation and increased seedling emergence and survival for both oaks, and height for valley oak. Study results indicate that under the environmental conditions at the study site, the 5.1 cm (2 in) planting depth provided the best balance between lesser acorn depredation and greater seedling emergence and survival for blue oak; the 5.1 cm and 10.3 cm (4 in) depths provided the best balance for valley oak.
Parent Publication
Citation
Tietje, William D.; Nives, Sherryl L.; Honig, Jennifer A.; Weitkamp, William H. 1991. Effect of Acorn Planting Depth on Depredation, Emergence, and Survival of Valley and Blue Oak. In: Standiford, Richard B., tech. coord. 1991. Proceedings of the symposium on oak woodlands and hardwood rangeland management; October 31 - November 2, 1990; Davis, California. Gen. Tech. Rep. PSW-GTR-126. Berkeley, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; p. 14-20
