While many forests and woodlands may be at increasing risk of climate-induced dieback, significant knowledge gaps remain in our understanding of the causes of climate-induced tree mortality. Recent publications underscore the critical importance of understanding the mechanisms that trigger plant mortality (Adams et al., 2009), particularly regarding features and traits that could be used as physiological indicators of tree death (McDowell et al., 2008). Alterations in wood formation and structure often occur prior to visual symptoms of crown decline. Thus, physiological, morphological, and anatomical traits related to xylem ('water-conducting pipes') may provide early-warning signals of drought-induced dieback. A better mechanistic understanding of drought-induced forest dieback would improve our ability to predict tree mortality and future changes in forest composition and coverage. The project aims at studying how drought episodes promote dieback via changes in xylem structure. Different genotypes of aspen (parkland region and the southern boundary of the boreal forest in western Canada), oak (Southern Europe) and pine (experiment) will be studied along gradients of moisture availability. Xylem-related traits that will be measured include ring-width, number of missing rings, quantitative wood anatomical structures (diameter and frequency of vessels/ tracheids, inter-vessel pit structure) as well as cavitation resistance, hydraulic conductivity, and water potentials.
Martínez-Sancho E., Dorado-Liñán I., Hacke, UG, Seidel, H.,& Menzel, A. (2017): "Contrasting Hydraulic Architectures of Scots Pine and Sessile Oak at Their Southernmost Distribution Limits". Front Plant Sci, 8(598).
Dorado-Liñán , I., Zorita, E., Martínez-Sancho, E. et al (2017): "Large -scale atmospheric circulation enhances the Mediterranean East-West tree growth contract at rear-edge deciduous forests", Agricultural and Forest Meteorology, 239(5).
Martínez-Sancho, E. et al. (2017): "Xylem adjustment of sessile oak at ist southern distribution limits", Tree Phisiology, 1-12(4).
Martínez-Sancho, E. et al. (2017): "Contrasting Hydraulic Architectures of Scots Pine and Sessile Oak at Their Southernmost Distribution Limits", Frontiers in Plant Science, 8(4).
Seidel, H., Schunk, C., Matiu, M., & Menzel, A. (2016): "Diverging Drought Resistance of Scots Pine Provenances Revealed by Infrared Thermography". Front Plant Sci, 7(1247).
Seidel, H., & Menzel, A. (2016): "Above-Ground Dimensions and Acclimation Explain Variation in Drought Mortality of Scots Pine Seedlings from Various Provenances". Front Plant Sci, 7(1014).