Frost resistance in alpine woody plants

Abstract

This report provides a brief review of key findings related to frost resistance in alpine woody plant species, summarizes data on their frost resistance, highlights the importance of freeze avoidance mechanisms, and indicates areas of future research. Freezing temperatures are possible throughout the whole growing period in the alpine life zone. Frost severity, comprised of both intensity and duration, becomes greater with increasing elevation and, there is also a greater probability, that small statured woody plants, may be insulated by snow cover. Several frost survival mechanisms have evolved in woody alpine plants in response to these environmental conditions. Examples of tolerance to extracellular freezing and freeze dehydration, life cycles that allow species to escape frost, and freeze avoidance mechanisms can all be found. Despite their specific adaption to the alpine environment, frost damage can occur in spring, while all alpine woody plants have a low risk of frost damage in winter. Experimental evidence indicates that premature deacclimation in Pinus cembra in the spring, and a limited ability of many species of alpine woody shrubs to rapidly reacclimate when they lose snow cover, resulting in reduced levels of frost resistance in the spring, may be particularly critical under the projected changes in climate. In this review, frost resistance and specific frost survival mechanisms of different organs (leaves, stems, vegetative and reproductive over-wintering buds, flowers, and fruits) and tissues are compared. The seasonal dynamics of frost resistance of leaves of trees, as opposed to woody shrubs, is also discussed. The ability of some tissues and organs to avoid freezing by supercooling, as visualized by high resolution infrared thermography, are also provided. Collectively, the report provides a review of the complex and diverse ways that woody plants survive in the frost dominated environment of the alpine life zone.

Species-environment interactions changed by introduced herbivores in an oceanic high-mountain ecosystem

“…Regarding plant regrowth, we found it to be lower at higher elevations, which we attribute to the fact that the severity and frequency of freezing temperatures significantly increase with elevation (Neuner 2014). The type of soil (pumice stones, Fig.…”

Environmental effects on fine‐scale spatial genetic structure in four Alpine keystone forest tree species

“…Since in Alpine conifers cambial activity occurs only above a mean daily temperature of 5.8–8.5°C (Rossi et al., ), we calculated CDD as the number of days with mean temperature between 0°C and 5°C in the period from 1 January to 31 March. Moreover, as Alpine trees only suffer damage from freezing below −10°C (Neuner, ), we computed FDD as the number of days with mean temperature below −10°C in the period from 1 November to the end of February (Greuell et al., ). CDD and FDD were calculated for each year and averaged for the period 2000–2010.…”

Perspectives on the Future of Ice Nucleation Research: Research Needs and Unanswered Questions Identified from Two International Workshops

“…Question 4.2 is focused on a potential ecological advantage conferred by the ice-nucleation phenotype. Ice nucleation plays an important role in frost injury in crops ( [122][123][124][125][126]; reviewed by [127]), and bacteria expressing ice-nucleating proteins may have a selective advantage as plant pathogens [108]. Ice-nucleating strains of Fusarium avenaceum [105] occupy a similar ecological niche (overwintering in cereal residues, and causing disease in small grains [128]) as non ice-nucleating strains of Fusarium graminearum [105], but the ecological role of the persistence of the ice-nucleating phenotype in these strains are presently unknown.…”