Pacific Southwest

Title: Germination Characteristics of Engelmann Oak and Coast Live Oak from the Santa Rosa Plateau, Riverside County, California

Author: Snow, Gerald E.

Date: 1991

Source: 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. 360-365

Station ID: GTR-PSW-126

Description: Over 2,000 acorns of Quercus agrifolia (coast live oak) and over 500 acorns of Q. engelmannii (Engelmann oak) were collected in the Jim Knight pasture area of the Santa Rosa Plateau. These were used to test for temperature and moisture conditions on germination of viable acorns in the laboratory under controlled environmental conditions. At 24°C Q. engelmannii had almost 90 percent germination after 6 days, while Q. agrifolia had about 20 percent (96 percent after 20 days). At 14°C completeness and speed of germination of Q. engelmannii was reduced to about 80 percent after 36 days, while Q. agrifolia had over 90 percent at 30 days. At 4°C Q. engelmannii had about 60 percent germination at 72 days, while Q. agrifolia had over 90 percent at 72 days. At varying degrees of moisture stress from field capacity to -100 bar atmosphere (at 20°C) Q. engelmannii had at least 70 percent germination of viable acorns after 36 days, while Q. agrifolia did not germinate in a-100 bar atmosphere, reached complete germination in a -10 bar PEG-vermiculite mixture after 60 days and took 132 days for complete germination under 100 percent relative humidity conditions. Drying (20°C, 45 percent RH) acorns for up to 3 weeks with 24 percent moisture loss had no effect on Q. engelmannii but Q. agrifolia lost 42,58 and 75 percent of their initial moisture after 1, 2 and 3 weeks drying and all the seeds were dead after 2 weeks. The "self-rooting" of Q. engelmannii is also discussed. These germination characteristics are related to the distribution of these two oak species in the field.

Keywords: 

View and Print this Publication (506 KB)

Publication Notes: 

• We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
• This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
• You may send email to pubrequest@fs.f ed.us to request a hard copy of this publication. (Please specify exactly which publication you are requesting and your mailing address.)

 Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

Citation

Snow, Gerald E.  1991.  Germination Characteristics of Engelmann Oak and Coast Live Oak from the Santa Rosa Plateau, Riverside County, California.   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. 360-365.