Growth, Photosynthesis, and Cold Tolerance of Eucalyptus benthamii Planted in the Piedmont of North Carolina


Inadequate cold tolerance of Eucalyptus spp. has limited a broader deployment beyond subtropical regions of the United States. We examined growth, photosynthetic rate, and cold tolerance of a cold-hardy Eucalypt (Eucalyptus benthamii) planted in North Carolina and compared the results with native Pinus taeda. After two growing seasons, E. benthamii surpassed P. taeda in both height (5.06 m, 1.34 m) and diameter (5.0 cm, 0.7 cm) growth, respectively. From April through November, E. benthamii’s mean photosynthetic rate (Ps) (13.82 µmol CO2 m−2s−1) was more than twice that of P. taeda (6.21 µmol CO2 m−2s−1). Similarly, mean Ps during winter months was 6.09 µmol CO2 m−2s−1 for E. benthamii compared to 2.73 µmol CO2 m−2s−1 for P. taeda. Laboratory assessments of cold tolerance demonstrated that, unlike P. taeda, E. benthamii had a limited ability to acclimate to seasonal temperature changes. The coldest temperature (Tm) where >50% of the tissue was damaged and recovery unlikely for E. benthamii was −13.4°C for leaves and −14.3°C for stems, whereas for P. taeda it was −29.9°C for leaves and −36.5°C for stems. The exceptional productivity of E. benthamii was not without trade-offs as all trees died after experiencing air temperatures of −12.8°C on January 7, 2014.

  • Citation: Butnor, John R; Johnsen, Kurt H; Anderson, Peter H; Hall, Kevin B; Halman, Joshua M; Hawley, Gary J; Maier, Christopher A; Schaberg, Paul G. 2019. Growth, Photosynthesis, and Cold Tolerance of Eucalyptus benthamii  planted in the Piedmont of North Carolina . Forest Science. 65(1): 59-67.
  • Keywords: freezing injury, relative electrolyte leakage, plantation, exotic
  • Posted Date: February 12, 2019
  • Modified Date: February 20, 2019
  • Requesting Print Publications

    Publication requests are subject to availability. Fiscal responsibility limits the hardcopies of publications we produce and distribute. Electronic versions of publications may be downloaded, distributed and printed.

    Please make any requests at

    Publication Notes

    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
    • Our online publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS webmaster if you notice any errors which make this publication unusable.
    • To view this article, download the latest version of Adobe Acrobat Reader.