Root morphology, stem growth and field performance of seedlings of two Mediterranean evergreen oak species raised in different container types M. Tsakaldimi 1 , T. Zagas, T. Tsitsoni & P. Ganatsas Department of Forestry and Natural Environment, Laboratory of Silviculture, Aristotle University of Thes- saloniki, University Campus, 54 124, P.O.Box 262, Thessaloniki, Greece. 1 Corresponding author* Received 8 October 2004. Accepted in revised form 17 February 2005 Key words: container seedlings, outplanting performance, Quercus coccifera, Quercus ilex, root morphology, stem growth Abstract Outplanting container-grown oak seedlings with undesirable shoot and root characteristics result in poor establishment and reduced field growth. The objective of this study was to determine the influence of container type on both above-and below-ground nursery growth and field performance of one-year old tap- rooted seedlings Quercus ilex L. and Quercus coccifera L. The experiment was conducted in an open-air nursery and the seedlings were grown in three container types. At the end of the nursery, growth period seedlingsÕ shoot height, diameter (5 mm above root collar), shoot and root biomass, root surface area, root volume and total root length were assessed. Then the seedlings were planted in the field and their survival and growth were recorded for two growing seasons after outplanting. The results showed a difference between the Quercus species in the effect of container type. Q. ilex seedlings raised in paper-pot had significantly greater height, diameter, shoot and root biomass and root volume than those raised in the other two container types. Similarly, Q. coccifera seedlings raised in paper-pot, had significantly greater above-and below-ground growth than those raised in the other two container types. Both oak species showed relatively low survival in the field; the mortality was mainly observed the first year after out- planting, especially after the summer dry period. However, 2 years after outplanting, the paper-pot seed- lings of the two oak species showed better field performance. Introduction In ecological studies, the evergreen sclerophylls are regarded as one of most typical compo- nents of the Mediterranean type vegetation (Saleo and LoGullo, 1990). Many restoration projects have established plantations of these evergreen resprouting species (Vallejo et al., 2000; Vilagrosa et al., 2003). Despite the great efforts in oak regeneration research, the suc- cessful planting of oaks is still fraught with uncertainty (Pope, 1993). Early attempts to introduce broad-leaved resprouting species to the Mediterranean basin (e.g., Quercus spe- cies) faced high seedling mortality, and until recently, nursery and field techniques were poorly developed for these two species (Pausas et al., 2004). In eastern Spain as well as in Greece, the field survival and growth of planted Mediterranean oaks are frequently very low (Hatzistathis et al., 1999; Pausas et al., 2004; Tsakaldimi, 2001; Vilagrosa et al., 2003; Villar- Salvador et al., 2004). The poor development of Quercus seedlings plantations, in some cases, could be attributed to the low quality of the planted seedlings. *E-mail: marian@for.auth.gr Plant and Soil (2005) 278:85–93 Ó Springer 2005 DOI 10.1007/s11104-005-2580-1