The effect of stratification and shade on germination of Nothofagus cliffortioides (Hook.f.) Oerst seeds

ABSTRACT

Seed stratification can substantially improve germinability. In glasshouse settings, knowledge of stratification requirements is critical for allowing effective control of germination. In addition, for species that seed irregularly, understanding how to break dormancy of aged seeds is important. This study tests whether moisture is required as well as cold conditions to stratify Nothofagus cliffortioides (Hook.f.) Oerst. (mountain beech) seeds, and whether shading during the germination period improves germination and survival. The seeds tested had been collected during a heavy mast year and stored dry for c. 2 years at −20°C. Dry cold stratification failed to break dormancy, with average germination (3.3%) not significantly different from unstratified controls (5.3%). In contrast, average germination of moist cold stratified seeds was at least four times higher (21.7%), with most germination occurring within 30 days. Hessian covers on trays had no impact on germination or survival. These results provide useful information for growing N. cliffortioides from seed and raise the possibility that lengthened drought periods under future climate regimes could affect natural Nothofagus regeneration by reducing the effectiveness of natural winter conditions for breaking seed dormancy.

KEYWORDS:

• Fuscospora
• New Zealand
• mast seeding
• Nothofagaceae
• restoration
• seed dormancy
• southern beech

Acknowledgements

We thank Jessica Paull and Adrian Smith-Beech for their assistance with the experimental setup.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data is provided as Supplementary Data S1.

Additional information

Funding

This work was supported by the Ministry for Primary Industries/Te Uru Rakau One Billion Trees Partnership under Grant 1BT-00062.