Seasonal changes in wood formation of Ulmus pumila and U. minor and its relation with Dutch elm disease

Authors

  • A. Solla,

    1. Biología y Producción de los Vegetales, Centro Universitario de Plasencia, Ingeniería Técnica Forestal, Universidad de Extremadura, Avenida Virgen del Puerto 2, 10600-Plasencia, Spain;
    Search for more papers by this author
  • J. A. Martín,

    1. Anatomía, Fisiología y Genética Forestal, ETSI de Montes, Universidad Politécnica de Madrid, Paseo de las Moreras s/n, 28040-Madrid, Spain
    Search for more papers by this author
  • P. Corral,

    1. Biología y Producción de los Vegetales, Centro Universitario de Plasencia, Ingeniería Técnica Forestal, Universidad de Extremadura, Avenida Virgen del Puerto 2, 10600-Plasencia, Spain;
    Search for more papers by this author
  • L. Gil

    Corresponding author
    1. Anatomía, Fisiología y Genética Forestal, ETSI de Montes, Universidad Politécnica de Madrid, Paseo de las Moreras s/n, 28040-Madrid, Spain
      Author for correspondence: Luis Gil Tel: +34 91 3367113 Fax: +34 91 5439557 Email: lgil@montes.upm.es
    Search for more papers by this author

Author for correspondence: Luis Gil Tel: +34 91 3367113 Fax: +34 91 5439557 Email: lgil@montes.upm.es

Summary

  • • Elms containing narrow and scattered vessels have been reported to be more resistant to Ophiostoma novo-ulmi (Dutch elm disease pathogen) than elms with large and contiguous vessels. However, recent measurements in Ulmus pumila and U. minor showed a contrary trend.
  • • The pin method was applied to 4-yr-old branches of eight clones planted in Madrid. During 2002, radial growth increments and vessel diameters were measured monthly, and beetle trapping was undertaken weekly.
  • • U. minor formed larger vessels at the beginning of the season, coinciding with a peak of captured beetles, but, up to June 15, vessels were larger for U. pumila. The number of vessels per group, the transversal area per vessel group, and the mean theoretical hydraulic conductances were significantly higher for U. minor on most dates.
  • • Researchers should take into consideration the seasonal changes in vessel size. The results highlight that seasonal variation of vessel diameters and hydraulic parameters, in combination with beetle abundance, are the main factors that could explain the different susceptibility of both elm species to O. novo-ulmi.

Ancillary