Survival of frosts below -38°C

Introduction
Survival of frosts below -38°CThe ability to determine winter frost resistance of woody plants is limited for two reasons: (1) Assessment of frost damage in midwinter is extremely difficult because results yielded by the currently available viability assays deviate greatly and (2) powerful and suitable freezing equipment that allows plants to be frozen at controlled freezing and thawing rates down to below the midwinter frost resistance of most Northern Hemisphere woody plants is not available. To overcome these limitations we developed a novel low temperature freezing system (LTFS) that makes it possible to conduct in situ freezing experiments in midwinter with full control of cooling and thawing rates down to -70°C. Frost resistance can be determined unequivocally by the re-growth test.

Research Questions

  • Development of a field portable low temperature freezing system (LTFS)
  • Reassessment of midwinter frost resistance of alpine timberline conifers in the field by the re-growth test
  • Freezing characteristics of conifers under field conditions
  • Survival of ultra low temperatures: Dipping of twigs still attached to the tree into liquid nitrogen (LN2 quenching)

Publications
BUCHNER, O., NEUNER, G.: A Low Temperature Freezing System to study effects of freezing temperatures down to -70°C on trees in situ. Tree Physiology, 29, 313-320. DOI 10.1093/treephys/tpn038 (2009).
BUCHNER, O., NEUNER, G.: Freezing cytorrhysis and critical temperature thresholds for photosystem II in the peat moss Sphagnum capillifolium. Protoplasma, 243(1), 63-71. DOI 10.1007/s00709-009-0053-8 (2010).
BUCHNER, O., NEUNER, G.: Winter frost resistance of Pinus cembra measured in situ at the alpine timberline as affected by temperature conditions. Submitted

Funding
2005-2010 FWF-Project P17992-B06 (PI: Gilbert NEUNER)

Personnel involved
Othmar BUCHNER
Gilbert NEUNER

Survival of frosts below -38°C