Taher Mechergui;Marta Pardos;Naceur Boussaidi;Brahim Hasnaoui;Douglass F. Jacob

Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), Centro de Investigacion Forestal, Madrid, Spain;Institut Sylvo-Pastoral de Tabarka, Tabarka, Tunisie;Faculté des Sciences de Bizerte (FSB), Jarzouna, Tunisie;Department of Forestry and Natural Resources, Purdue University, West Lafayette, US

Quercus suber L.;afforestation;tree shelter;mulching;seedling growth;polycyclism;WEED-CONTROL STRATEGIES;POLYETHYLENE MULCH;SHOOT GROWTH;ESTABLISHMENT;PLANTATIONS;DECOMPOSITION;TREESHELTERS;PROTECTION;SURVIVAL;HEIGH

The need for reforestation in cork oak （Quercus suber L.） areas is challenged by difficulties. Principal among these is herbivory of young plants, vegetative competition, and slow growth rates of cork oak seedlings. We evaluated the early development of cork oak seedlings treated using tree shelters and mulching in northwestern Tunisia. We tested three tree shelter treatments （non-vented, vented, and control） to shield seedlings from animal damage and five mulch types to control competing vegetation （Italian Stone Pine, Lentisk, combination of Italian Stone Pine and Lentisk （organic mulches）, gravel （inorganic mulch） and no mulch）. At the end of the two-year experiment, sheltered seedlings were 89-99% taller than unshelteredseedlings and had higher numbers and lengths of shoot growth flushes. In contrast, both stem diameter growth and dry weight biomass （from samples extracted after two years） were significantly reduced inside tree shelters. Root-to-shoot ratio was not significantly different in sheltered vs. unsheltered seedlings, suggesting that tree shelters do not adversely affect this parameter. Mulching alone did not favour growth, but could be beneficial when combined with tree shelters. The combination of vented tree shelters and gravel mulch was the most effective treatment for promoting diameter, height and stem volume growth.