Ecophysiological variables influencing Aleppo pine seed and cone production: a review

Abstract

The most interesting factors associated with seed and cone production of Aleppo pine were largely reviewed to identify broad patterns and potential effectiveness of reforestation efforts and planning. Aleppo pine cone production and seed yields are relatively variable, with differences between spatial and temporal influences. These differences are considered, mainly between (i) year, (ii) stand characteristics and (iii) individual tree measurements. Annual variability among populations was recorded for cone production per tree, based on influencing factors such as genetic characteristics, wetness, nutrient availability, insect pests and disease. In addition, some factors may affect Aleppo pine tree growth directly but may be affecting seed and cone production indirectly. Therefore, reduced stand density results in less competition among Aleppo pine trees and accompanying understory flora, which subsequently increases the stem diameter and other tree dimensions, including seed production. This review suggests that reforestation planning, particularly thinning, will result in improved tree morphology that will increase Aleppo pine seed and cone crops. Wildfire intensity and stand conditions such as light and soil nutrient status are also examined.

Keywords: cone crops; forest productivity; fruit development; physiological responses; regulation factors; seed yields.