@article{EilmannWeberRiglingetal.2006, author = {Eilmann, Britta and Weber, Pascale and Rigling, Andreas and Eckstein, Dieter}, title = {Growth reactions of Pinus sylvestris L. and Quercus pubescens Willd. to drought years at a xeric site in Valais, Switzerland}, series = {Dendrochronologia}, volume = {23}, journal = {Dendrochronologia}, number = {3}, issn = {1612-0051 (Online)}, doi = {doi:10.1016/j.dendro.2005.10.002}, pages = {121 -- 132}, year = {2006}, language = {en} } @article{WeberRiglingEilmannetal.2008, author = {Weber, Pascale and Rigling, Andreas and Eilmann, Britta and Mayer, Phillip and Wohlgemuth, Thomas and Dobbertin, Matthias}, title = {Verj{\"u}ngung und Konkurrenz der Flaumeiche im Wallis}, series = {Informationsblatt Wald}, journal = {Informationsblatt Wald}, number = {22}, issn = {1661-5859 (Online)}, pages = {1 -- 3}, year = {2008}, language = {de} } @article{EilmannZweifelBuchmannetal.2009, author = {Eilmann, Britta and Zweifel, Roman and Buchmann, Nina and Fonti, Patrick and Rigling, Andreas}, title = {Drought-induced adaptation of the xylem in Scots pine and pubescent oak}, series = {Tree Physiology}, volume = {29}, journal = {Tree Physiology}, number = {8}, publisher = {Heron}, address = {Victoria, BC}, issn = {0829-318X (Print)}, doi = {10.1093/treephys/tpp035}, pages = {1011 -- 1020}, year = {2009}, 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{EilmannBuchmannSiegwolfetal.2010, author = {Eilmann, Britta and Buchmann, Nina and Siegwolf, Rolf and Saurer, Matthias and Cherubini, Paolo and Rigling, Andreas}, title = {Fast response of Scots pine to improved water availability reflected in tree-ring width and δ13C}, series = {Plant, Cell and Environment}, volume = {33}, journal = {Plant, Cell and Environment}, number = {8}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1365-3040 (Online)}, doi = {10.1111/j.1365-3040.2010.02153.x}, pages = {1351 -- 1360}, year = {2010}, abstract = {Drought-induced forest decline, like the Scots pine mortality in inner-Alpine valleys, will gain in importance as the frequency and severity of drought events are expected to increase. To understand how chronic drought affects tree growth and tree-ring δ13C values, we studied mature Scots pine in an irrigation experiment in an inner-Alpine valley. Tree growth and isotope analyses were carried out at the annual and seasonal scale. At the seasonal scale, maximum δ13C values were measured after the hottest and driest period of the year, and were associated with decreasing growth rates. Inter-annual δ13C values in early- and latewood showed a strong correlation with annual climatic conditions and an immediate decrease as a response to irrigation. This indicates a tight coupling between wood formation and the freshly produced assimilates for trees exposed to chronic drought. This rapid appearance of the isotopic signal is a strong indication for an immediate and direct transfer of newly synthesized assimilates for biomass production. The fast appearance and the distinct isotopic signal suggest a low availability of old stored carbohydrates. If this was a sign for C-storage depletion, an increasing mortality could be expected when stressors increase the need for carbohydrate for defence, repair or regeneration.}, language = {en} } @article{EgliAyerPeteretal.2010, author = {Egli, Simon and Ayer, Fran{\c{c}}ois and Peter, Martina and Eilmann, Britta and Rigling, Andreas}, title = {Is forest mushroom productivity driven by tree growth? Results from a thinning experiment}, series = {Annals of Forest Science}, volume = {67}, journal = {Annals of Forest Science}, number = {5}, publisher = {Springer}, address = {Paris}, issn = {1286-4560 (Print)}, doi = {10.1051/forest/2010011}, pages = {509}, year = {2010}, abstract = {• Most of the edible forest mushrooms are mycorrhizal and depend on carbohydrates produced by the associated trees. Fruiting patterns of these fungi are not yet fully understood since climatic factors alone do not completely explain mushroom occurrence. • The objective of this study was to retrospectively find out if changing tree growth following an increment thinning has influenced the diversity patterns and productivity of associated forest mushrooms in the fungus reserve La Chan{\´e}az, Switzerland. • The results reveal a clear temporal relationship between the thinning, the growth reaction of trees and the reaction of the fungal community, especially for the ectomycorrhizal species. The tree-ring width of the formerly suppressed beech trees and the fruit body number increased after thinning, leading to a significantly positive correlation between fruit body numbers and tree-ring width. • Fruit body production was influenced by previous annual tree growth, the best accordance was found between fruit body production and the tree-ring width two years previously. • The results support the hypothesis that ectomycorrhizal fruit body production must be linked with the growth of the associated host trees. Moreover, the findings indicate the importance of including mycorrhizal fungi as important players when discussing a tree as a carbon source or sink.}, 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} } @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{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{RiglingElkinDobbertinetal.2012, author = {Rigling, Andreas and Elkin, Ch{\´e} and Dobbertin, Matthias and Eilmann, Britta and Giuggiola, Arnaud and Wohlgemuth, Thomas and Bugmann, Harald}, title = {Wald und Klimawandel in der inneralpinen Trockenregion Visp}, series = {Schweizerische Zeitschrift f{\"u}r Forstwesen}, volume = {163}, journal = {Schweizerische Zeitschrift f{\"u}r Forstwesen}, number = {12}, publisher = {Schweizerischer Forstverein}, address = {Z{\"u}rich}, issn = {2235-1469 (Online)}, doi = {10.3188/szf.2012.0481}, pages = {481 -- 492}, year = {2012}, abstract = {Der Temperaturanstieg der vergangenen Jahrzehnte war in Gebirgsregionen besonders ausgepr{\"a}gt. Sollte sich dieser Temperaturtrend im 21. Jahrhundert fortsetzen, dann d{\"u}rf-ten sich auch die H{\"a}ufigkeit und Intensit{\"a}t von Niederschl{\"a}-gen und Trockenperioden ver{\"a}ndern, was die Waldwirtschaft vor grosse Herausforderungen stellen wird. Trockenheit ist ein entscheidender Faktor f{\"u}r die Wald{\"o}kosysteme der inner-alpinen T{\"a}ler, wo seit Jahren trockenheitsbedingtes Baum-sterben festgestellt wird. Der vorliegende Beitrag hat zum Ziel, die Sensitivit{\"a}t der verschiedenen Wald{\"o}kosysteme ge-gen{\"u}ber Klimawandel und alternative, teilweise extreme Bewirtschaftungsvarianten in der Region Visp zu testen. Me-thodische Ans{\"a}tze wie Monitoring, Feldexperimente und dy-namische Modellierung wurden kombiniert, und es wurden verschiedene {\"O}kosystemleistungen ber{\"u}cksichtigt, so Holz-produktion, Schutz vor Naturgefahren, Kohlenstoffspeiche-rung und Aspekte der Biodiversit{\"a}t. Die Resultate deuten da-rauf hin, dass auf den Trockenstandorten der Tieflagen die einheimischen Baumarten an ihre physiologischen Grenzen stossen und l{\"a}ngerfristig {\"u}ber alternative Baumarten nach-gedacht werden sollte. In den mittleren Lagen d{\"u}rften Tro-ckenheit und Schadinsekten wie die Borkenk{\"a}fer die zuk{\"u}nf-tige Waldentwicklung steuern. In den Hochlagen hingegen werden sich die W{\"a}lder ausdehnen und besser wachsen als heute. Alle untersuchten {\"O}kosystemleistungen werden ge-bietsweise starken Ver{\"a}nderungen unterworfen sein. Die dis-kutierten Bewirtschaftungsvarianten scheinen dazu geeignet, die Wasserverf{\"u}gbarkeit der Best{\"a}nde, haupts{\"a}chlich in tief-eren Lagen, zu erh{\"o}hen und dadurch die Widerstandskraft der B{\"a}ume gegen{\"u}ber Trockenperioden vor{\"u}bergehend zu st{\"a}rken. Es ist aber davon ausgehen, dass nur verh{\"a}ltnism{\"a}s-sig starke Eingriffe wesentliche Effekte erzielen k{\"o}nnen. Die Verkn{\"u}pfung von Umweltmonitoring, Feldexperimenten und Modellierung unter Miteinbezug von {\"O}kosystemleistungen ist vielversprechend, da sie eine differenzierte Absch{\"a}tzung des zuk{\"u}nftigen Landschaftswandels und seiner Effekte auf die Waldleistungen erm{\"o}glicht.}, language = {de} }