Overwintering of herbaceous plants in a changing climate. Still more questions than answers

• Published in: Plant science (Limerick) Vol. 225; pp. 34 - 44
• Main Authors: Rapacz, Marcin, Ergon, Åshild, Höglind, Mats, Jørgensen, Marit, Jurczyk, Barbara, Østrem, Liv, Rognli, Odd Arne, Tronsmo, Anne Marte
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01.08.2014
• Subjects: Adaptation, Physiological; Climate; Climate Change; Forage grasses; Freezing tolerance; Plant breeding; Plant Diseases; Plant Physiological Phenomena; Plants; Seasons; Snow; Snow-mould fungi; Stress, Physiological; Temperature; Winter hardiness; Climate change; Freezing tolerance; RCPs; Plant breeding; IPCC; Winter hardiness; Snow-mould fungi; Forage grasses
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2014.05.009

•The increase in temperature will decrease the risk of extreme frost during winter.•The risk of plant winterkill will not necessarily be lower.•Overwintering will be affected by complex environmental interactions.•The final effect is unpredictable, but may be very significant.•Understanding climate change effects on overwintering is crucial in plant breeding. The increase in surface temperature of the Earth indicates a lower risk of exposure for temperate grassland and crop to extremely low temperatures. However, the risk of low winter survival rate, especially in higher latitudes may not be smaller, due to complex interactions among different environmental factors. For example, the frequency, degree and length of extreme winter warming events, leading to snowmelt during winter increased, affecting the risks of anoxia, ice encasement and freezing of plants not covered with snow. Future climate projections suggest that cold acclimation will occur later in autumn, under shorter photoperiod and lower light intensity, which may affect the energy partitioning between the elongation growth, accumulation of organic reserves and cold acclimation. Rising CO2 levels may also disturb the cold acclimation process. Predicting problems with winter pathogens is also very complex, because climate change may greatly influence the pathogen population and because the plant resistance to these pathogens is increased by cold acclimation. All these factors, often with contradictory effects on winter survival, make plant overwintering viability under future climates an open question. Close cooperation between climatologists, ecologists, plant physiologists, geneticists and plant breeders is strongly required to predict and prevent possible problems.