1. GENETIC/PYSIOLOGICAL ADAPTIVE TRAITS
FACTORS ASSOCIATED WITH COLD HARDINESS
OTHER FACTORS

2. CONIFER COLD HARDINESS
(Bannister and Neuner 2001)

3. CONIFER COLD HARDINESS
CONIFER SEEDS
Temperature resulting in 50% survival (LT50)
Germination subject to freezing: -196°C
(Hawkins et al. 2003)

4. CONIFER COLD HARDINESS
NEEDLES
WHOLE ROOT SYSTEM
(Bigras et al. 2001)

5. ANTHOCYANIN ACCUMULATION
Anthocyanin ~ natural sunscreen against high visible irradiance and UV-B radiation
Characteristic ‘purpling’
Accumulation in needle surface epidermal cells
Onset: shortened photoperiod and low temperature
(Oquist et al. 2001)

6. AMINO ACIDS AND PROTEINS
CRYOPROTECTION
Enhance cold tolerance by preserving and stabilizing cell structures
Increases water deficit resistance and reduces amount of free water
CARBOHYDRATES
AMINO ACIDS AND PROTEINS
LIPIDS
(Zwiazek et al. 2001)

7. CRYOPROTECTION
(Zwiazek et al. 2001, Hawkins et al )

8. . WINTER CAVITATION Cavitation = nucleation of xylem water
Lodgepole % loss of conductivity (representing cavitation) in shoot xylem over winter months .
(Sperry and Robson 2001)

9. Wheras spruce and fir did
SUPERCOOLING
Supercooling = winter survival mechanism in many tree species especially hardwoods
Supercooling:
Prevents dessication
Inhibits water loss to extracelluar spaces
Lodgepole and Poderosa pine did not exhibit freezing of supercooled water beyond -40C
Wheras spruce and fir did
(Sutinen et al. 2001)

10. TEMPORAL ASSOCIATIONS OF COLD HARDINESS
Hardening and Dehardening

11. CONIFER COLD HARDINESS
Hardening onset:
(Bigras et al. 2001)

12. HARDENING AND DEHARDENING
Lodgepole vs. Spruce
Later growth cessation
Later hardeneing
Tendancy to deharden in winter
earlier dehardening
Earlier growth
(Nilsson 2001)

13. OTHER GENETIC/PYSIOLOGICAL TRAITS
HEAT RESISTANCE
DROUGHT RESISTANCE
Salt resistance
Water Use Efficiency (WUE)

14. NON-COLD HARDINESS/ OTHER TRAITS
HEAT RISISTANCE
Lodgepole - lower mortality rates than those of aspen (Populus
tremuloides Michx.), Engelmann spruce (Picea engelmannii Parry ex Engelm.), and Douglas-fir (Pseudotsuga menziesii
Ability to withstand surface fires over spruce
(Dickinson and Johnson 2004)

15. NON-COLD HARDINESS/ OTHER TRAITS
DROUGHT RESISTANCE
SALT RESISTANCE
DRY BIOMASS PRODUCTION: 
lodgepole pine
jack pine
white spruce 
OVERALL SURVIVAL: 
jack pine
lodgepole pine
white spruce 
(Khasa et al. 2002)

16. NON-COLD HARDINESS/ OTHER TRAITS
DROUGHT RESISTANCE
WATER USE EFFICIENCY (WUE)
Lodgelpole WUE increases with availability of water
WUE and drought – tradeoff b/t survivability and competition
(Guy and Holowachuck 2001)

17. REFERENCES
Aitken, S Adapting Forest Gene Resource Management to Climate Change. Forest Genetics Council of B.C., Canada.
Bannister, P. and Neuner, G Frost Resistance and the Distribution of Conifers. In Conifer cold hardiness. Edited by F.J. Bigras and S.J. Columbo. Kluwer Academic Publishers, Dordrecht, The Netherlands. pp
Dickinson, M.B., and Johnson, E.A Temperature-dependent rate models of vascular cambium cell mortality. Canadian Journal of Forest Research. 34: 546–559.
Fries, A., Lindgren, D., Ying, C.C., Ruotsalainen, S., Lindgren, K., Elfving, B., and Karlmats, U The effect of temperature on site index in western Canada and Scandinavia estimated from IUFRO Pinus contorta provenance experiments. Canadian Journal of Forest Research. 30: 921–929.
Guy, R.D., and Holowachuk, D.L Population differences in stable carbon isotope ratio of Pinus contorta Dougl. ex Loud.: relationship to environment, climate of origin, and growth potential. Canadian Journal of Botany. 79: 274–283.
Hawkins, B.J., Guest, H.J., and Kolotelo, D Freezing tolerance of conifer seeds and germinants. Tree Physiology. 23: 1237–1246.
Khasa, P.D., Hambling, B., Kernaghan, G., Fung, M., and Ngimbi, E Genetic variability in salt tolerance of selected boreal woody seedlings. Forest Ecology and Management. 165: 257–269.
Nilsson, J.E Seasonal Changes in Phenological Traits and C-populations from Plus-trees of Pinus sylvestris and Pinus contorta of Various Geographical Origins. Scandinavian Journal of Forest Research. 16: 7-20.
Oquist, G., Gardestrom, P., and Huner, N.P.A Metabolic Changes During Cold Acclimation and Subsequent Freezing and Thawing. In Conifer cold hardiness. Edited by F.J. Bigras and S.J. Columbo. Kluwer Academic Publishers, Dordrecht, The Netherlands. pp
Rehfeldt, G.E., Ying, C.C., Spittlehouse, D.L, and Hamilton, D.A Genetic Response to Climate in Pinus contorta: Niche Breadth, Climate Change, and Reforestation. Ecological Monographs. 69(3):
Sperry, J.S., and Robson, D.J Xylem Cavitation and Freezing in Conifers. In Conifer cold hardiness. Edited by F.J. Bigras and S.J. Columbo. Kluwer Academic Publishers, Dordrecht, The Netherlands. pp
Zwiazek, J.J., Renault, S., Croser, C., Hansen, J., and Bech, E Biochemical and Biophysical Changes in Relation to Cold Hardiness. In Conifer cold hardiness. Edited by F.J. Bigras and S.J. Columbo. Kluwer Academic Publishers, Dordrecht, The Netherlands. pp