The Occurrence of Creeping Plants in Plantations: A Dilemma of Cork Oak Forest Regeneration in Tunisia

Boutheina STITI ¹, Ali KHORCHANI ², Amar ELHAJ³, Abdelhamid KHALDI ⁴

National Research Institute of Rural Engineering, Water and Forestry, University of Carthage, BP10, 2080, Ariana, Tunisia.

Abstract: As natural regeneration and direct sowing have been considered difficult, planting was adopted as a solution to attenuate the decline of cork oak forest. However, Tunisian planted cork oaks showed a troublesome phenomenon characterized by the presence of creeping plants which has a negative influence on height growth and cork production. This study aimed to estimate, for the first time in Tunisia, the percent of creeping cork oaks among those planted between 1995 and 2008 and to make a diagnosis in order to propose solutions to this problem. The percentage of creeping plants was determined in 2014 within 35 plots installed in 13 perimeters, situated in northern Tunisia. Crown diameter and total height were measured for the whole plants. Moreover, the creeping plants were were distinghished and inventoried in categories according to shoot ramification. The average survival rate, estimated at 55±30%, varied between 0% and 100% depending on perimeter. The average percentage of creeping plants reached 82% ranging between 0 and 100%, which reflects the extent of this phenomenon. Furthermore, 64.3% of creeping plants were classified in category I (1 main stem) where as 12.41% and 23.29% were classified in categories II (2 ramifications) and III (3 or more ramifications), respectively. The percent of creeping plants was negatively correlated to altitude and positively correlated to soil hardnes; indicateing high grazing and low possibility for plants to grow.

Keywords: cork oak, creeping plants, shoot growth, overgrazing, Mediteranean climate.

Pages: 36 – 46 | Full PDF Paper