First frost: Effects of single and repeated freezing events on acclimation in Picea abies and other boreal and temperate conifers |
| |
Authors: | G Richard Strimbeck Trygve D Kjellsen |
| |
Institution: | 1. Department of Biology, Norwegian University of Science and Technology, Realfagbygget, Høgskoleringen 5, 7491 Trondheim, Norway;2. StatoilHydro Research Centre, 7005 Trondheim, Norway |
| |
Abstract: | In experiments with needles of Picea abies, we tested the specific hypothesis that a single night of freezing acts as a signal that triggers a rapid increase in low temperature (LT) tolerance, and the more general hypothesis that repeated or prolonged freezing stimulates increased LT acclimation. In three growth chamber experiments involving acclimation under early- to mid-autumn light and temperature conditions followed by one or more freezing treatments, we found no significant effect of a single night of freezing on LT tolerance, and only limited and inconsistent effects of repeated and prolonged freezing. We also tested the effect of prolonged storage at −5 °C on LT tolerance on samples of three boreal and three temperate conifer species during acclimation under field conditions, and again found no consistent enhancement of LT tolerance attributable to freezing in either group. In agreement with our own and others’ anecdotal observations that some species can attain nearly maximal LT tolerance in the absence of freezing under field conditions, we conclude that freezing is neither required nor a major influence in LT acclimation, at least in well-studied boreal conifer species, while the effects of freezing on temperate conifers are not as well-documented. We conclude that freezing treatment of conifer seedlings to ensure sufficient hardiness for late planting seems to offer little practical advantage. |
| |
Keywords: | Conifer Frost Freezing Cold Tolerance Hardiness Acclimation |
本文献已被 ScienceDirect 等数据库收录! |
|