Comparing growth and form of coast redwood selfs and outcrosses

Abstract

We now report 22 years of new data and observations from the third of three small projects evaluating the effects of inbreeding in coast redwood (Sequoia sempervirens (D. Don) Endl.). We also briefly summarize previously-reported effects of inbreeding on redwood’s cone production, seed set, germination percentage, nursery growth and survival, rooting of juvenile cuttings, and their growth and survival in field plantings. Offspring resulting from self-pollinations were compared to offspring from controlled outcrosses of the same seed-parents. Milder forms of inbreeding, likely among offspring of wind-pollinated redwoods, are likely to exhibit performances intermediate between those of selfs and outcrosses. Effects of self-level inbreeding were found to be small or absent in favorable conditions, increasing to serious or disastrous when the redwoods encounter competition or are grown in unfavorable or stressful environments. Deploying clones of outcrossed offspring will eliminate the possibility of inbreeding-caused poor performance of planted redwoods.

Parent Publication

• Coast redwood science symposium—2016: Past successes and future direction

Citation

Berrill, John-Pascal; Libby, William J. 2017. Comparing growth and form of coast redwood selfs and outcrosses. In: Standiford, Richard B.; Valachovic, Yana, tech cords. Coast redwood science symposium—2016: Past successes and future direction. Proceedings of a workshop. Gen. Tech. Rep. PSW-GTR-258. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 229-240.