ABSTRACT

Understanding how tree species respond to drought in their natural environment is needed to predict forest adaptation and management practices under global environmental changes. This study was carried out to determine physiological and biochemical responses to variations in environmental conditions of three provenance of Pinus halepensis. Our study consists in particularly to determine the intra-specific variability in water deficit responses of Aleppo pine using gas exchange measurements and biochemical markers such as proline, soluble sugars content, and chlorophyll pigments. The results showed a significant difference between the three provenances of Aleppo pine. The considerable decrease in photosynthetic capacity during the summer season coincides not only with the reduction of stomatal closure but also with a gradual decline in the content of chlorophyll pigments. In addition, a very important accumulation of proline and sugars in the aerial organs was recorded during the summer season, especially in the Italian provenance. Gas exchange exhibited significant differences (p < .05) among the months studied, with the highest values being for March (with greater water availability). Our results underscore the need to consider seasonal drought tolerance when selecting tree species for specific reforestation sites.

摘要

需要了解树种如何应对其自然环境中的干旱，以预测全球环境变化下的森林适应和管理实践。本研究旨在确定黑松三个种源对环境条件变化的生理和生化反应。. 我们的研究特别包括使用气体交换测量和生化标记（如脯氨酸、可溶性糖含量和叶绿素色素）确定阿勒颇松的水分亏缺反应的种内变异性。结果表明，阿勒颇松的三个种源之间存在显着差异。夏季光合能力的显着下降不仅与气孔关闭的减少相吻合，而且与叶绿素色素含量的逐渐下降相吻合。此外，在夏季，特别是在意大利产地，地上器官中脯氨酸和糖的积累非常重要。气体交换表现出显着差异（p< .05) 在研究的月份中，最高值出现在 3 月份（可用水量更大）。我们的结果强调在为特定的重新造林地点选择树种时需要考虑季节性耐旱性。