@article{EilmannSterckWegneretal.2014, author = {Eilmann, Britta and Sterck, Frank J. and Wegner, L. and de Vries, Sven M. G. and von Arx, G. and Mohren, Godefridus M. J. and den Ouden, Jan and Sass-Klaassen, Ute G. W.}, title = {Wood structural differences between northern and southern beech provenances growing at a moderate site}, series = {Tree Physiology}, volume = {34}, journal = {Tree Physiology}, number = {8}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1758-4469 (Online)}, doi = {10.1093/treephys/tpu069}, pages = {882 -- 893}, year = {2014}, language = {en} } @article{EilmannRigling2012, author = {Eilmann, Britta and Rigling, Andreas}, title = {Tree-growth analyses to estimate tree species' drought tolerance}, series = {Tree Physiology}, volume = {32}, journal = {Tree Physiology}, number = {2}, editor = {Abrams, Marc}, publisher = {Oxford University Press}, address = {Oxford}, issn = {0829-318X (Print)}, doi = {10.1093/treephys/tps004}, pages = {178 -- 187}, year = {2012}, abstract = {Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species.}, language = {en} } @article{EilmannZweifelBuchmannetal.2011, author = {Eilmann, Britta and Zweifel, Roman and Buchmann, Nina and Graf Pannatier, Elisabeth and Rigling, Andreas}, title = {Drought alters timing, quantity, and quality of wood formation in Scots pine}, series = {Journal of Experimental Botany}, volume = {62}, journal = {Journal of Experimental Botany}, number = {8}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1460-2431 (Online)}, doi = {10.1093/jxb/erq443}, pages = {2763 -- 2771}, year = {2011}, language = {en} } @article{DobbertinEilmannBleuleretal.2010, author = {Dobbertin, Matthias and Eilmann, Britta and Bleuler, Peter and Giuggiola, Arnaud and Graf Pannatier, Elisabeth and Landolt, Werner and Schleppi, Patrick and Rigling, Andreas}, title = {Effect of irrigation on needle morphology, shoot and stem growth in a drought-exposed Pinus sylvestris forest}, series = {Tree Physiology}, volume = {30}, journal = {Tree Physiology}, number = {3}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1758-4469 (Online)}, doi = {10.1093/treephys/tpp123}, pages = {346 -- 360}, year = {2010}, abstract = {In Valais, Switzerland, Scots pines (Pinus sylvestris L.) are declining, mainly following drought. To assess the impact of drought on tree growth and survival, an irrigation experiment was initiated in 2003 in a mature pine forest, approximately doubling the annual precipitation. Tree crown transparency (lack of foliage) and leaf area index (LAI) were annually assessed. Seven irrigated and six control trees were felled in 2006, and needles, stem discs and branches were taken for growth analysis. Irrigation in 2004 and 2005, both with below-average precipitation, increased needle size, area and mass, stem growth and, with a 1-year delay, shoot length. This led to a relative decrease in tree crown transparency (-14\%) and to an increase in stand LAI (+20\%). Irrigation increased needle length by 70\%, shoot length by 100\% and ring width by 120\%, regardless of crown transparency. Crown transparency correlated positively with mean needle size, shoot length and ring width and negatively with specific leaf area. Trees with high crown transparency (low growth, short needles) experienced similar increases in needle mass and growth with irrigation than trees with low transparency (high growth, long needles), indicating that seemingly declining trees were able to 'recover' when water supply became sufficient. A simple drought index before and during the irrigation explained most of the variation found in the parameters for both irrigated and control trees.}, language = {en} } @article{RiglingEilmannKoechlietal.2010, author = {Rigling, Andreas and Eilmann, Britta and Koechli, Roger and Dobbertin, Matthias}, title = {Mistletoe-induced crown degradation in Scots pine in a xeric environment}, volume = {30}, number = {7}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1758-4469 (Online)}, doi = {10.1093/treephys/tpq038}, pages = {845 -- 832}, year = {2010}, abstract = {Increasing Scots pine (Pinus sylvestris L.) mortality has been recently observed in the dry inner valleys of the European Alps. Besides drought, infection with pine mistletoe (Viscum album ssp. austriacum) seems to play an important role in the mortality dynamics of Scots pines, but how mistletoes promote pine decline remains unclear. To verify whether pine mistletoe infection weakens the host via crown degradation, as observed for dwarf mistletoes, we studied the negative effects of pine mistletoe infestation on the photosynthetic tissues and branch growth of pairs of infested and non-infested branches. Pine mistletoe infection leads to crown degradation in its host by reducing the length, the radial increment, the ramification, the needle length and the number of needle years of the infested branches. This massive loss in photosynthetic tissue results in a reduction in primary production and a subsequent decrease in carbohydrate availability. The significant reduction in needle length due to mistletoe infection is an indication for a lower water and nutrient availability in infested branches. Thus, mistletoe infection might lead to a decrease in the availability of water and carbohydrates, the two most important growth factors, which are already shortened due to the chronic drought situation in the area. Therefore, pine mistletoe increases the risk of drought-induced mortality of its host when growing in a xeric environment.}, language = {en} }