Response of Pinus sylvestris L. to recent climatic events in the French Mediterranean region

• Published in: Trees (Berlin, West) West), 2009, Vol.23 (4), p.843-853
• Main Authors: Thabeet, Ali, Vennetier, Michel, Gadbin-Henry, Claude, Denelle, Nicole, Roux, Maurice, Caraglio, Yves, Vila, Bruno
• Format: Article
• Language: English
• Subjects: Agricultural sciences; Agriculture; Biodiversity and Ecology; Biomedical and Life Sciences; Climatic conditions; Climatology; Development Biology; Drought; Earth Sciences; Environmental Sciences; Environmental studies; Evergreen trees; Forest productivity; Forestry; Forests; Global Changes; Humanities and Social Sciences; Life Sciences; Morphogenesis; Original Paper; Pine trees; Plant Anatomy/Development; Plant Pathology; Plant Physiology; Plant Sciences; Plant species; Sciences of the Universe; Silviculture, forestry
• ISSN: 0931-1890; 1432-2285
• DOI: 10.1007/s00468-009-0326-z

Exceptional climatic events from 2003 to 2005 (scorching heat and drought) affected the whole of the vegetation in the French Mediterranean region and in particular the Scots pine (Pinus sylvestris L.), one of the most important forest tree species in this area. To understand its response to these extreme conditions, we investigated its radial growth, branch length growth, architectural development and reproduction for the period 1995-2005, and linked these variables to climatic parameters. We used four plots situated in southeastern France and presenting different levels of site quality and potential forest productivity. The results show that: (1) the climatic episode 2003-2005 was highly detrimental to the growth (bole and branches), crown development, and cone production but favored the production of male flowers; (2) these variables depend on climatic factors of both the current and previous years; (3) the 2003 scorching heat impact was strong but was mainly apparent from 2004; it was part of a 6-year-long unfavorable cycle beginning in 2000, characterized by high minimum and maximum temperatures and very dry springs; (4) in spite of a significant effect of site quality, the Scots pine's response to extreme climatic conditions was homogeneous in the French Mediterranean area; and (5) the stress induced by poor site conditions generally resulted in the same consequences for tree growth, architecture, and reproduction as in unfavorable climatic conditions.