Aleppo Pine Seed Production of Several Tunisian Ecotypes Planted in a Coastal Forest Stand

Abstract

The demand of Aleppo pine seeds has risen largely to reach the Mediterranean countries necessities in the last decades. To study seed cone production of the species, 33 blocs (12x10m; 120m2) were planted with a limited number of Tunisian Aleppo pine ecotypes where only twelve are selected here to be surveyed. During plantations all ecotypes are spaced two meter each other. Selected ecotypes are evaluated for their survival rates, measured for their epidometric variables (total height (Ho) and their diameter at breast height (DBH)). Therefore, the average tree characteristic for each ecotype is defined as a representing tree and then an overall of 40 trees were used for cones harvesting. Consequently, seed and cone production variability between Aleppo pine ecotypes is detected using simple regression analysis. Results showed an overall survival rate of 82.9% within the site since 1963. High significant (p<0.01) linear positive relationship (Ho-DBH was recorded across ecotypes. Ecotypes variability is noticed for all the measured parameters including seed cone production parameters. However, coastal forest Aleppo pine stand showed an overall produced seed cone number less than the half (50 Cones/tree) in comparison to non-coastal forest within Tunisia. Similarly, in the coastal forest, the produced cones size and weight are often smaller and have less seeds contents than those produced within non-coastal forests. Likewise, we thought that cone traits are a major factor influencing seed yield in coastal forest stands. Finally, obtained results can be used as a scientific support to reach futures investigations research work in others Aleppo pine planted zones in Tunisia.