@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}
}
@article{RiglingBiglerEilmannetal.2012,
  author    = {Rigling, Andreas and Bigler, Christof and Eilmann, Britta and Feldmeyer-Christe, Elisabeth and Gimmi, Urs and Ginzler, Christian and Graf, Ulrich and Mayer, Phillip and Vacchiano, Giorgio and Weber, Pascal and Wohlgemuth, Thomas and zweifel, Roman and Dobbertin, Matthias},
  title     = {Driving factors of a vegetation shift from Scots pine to pubescent oak in dry Alpine forests},
  series = {Global Change Biology},
  volume    = {19},
  journal   = {Global Change Biology},
  number    = {1},
  publisher = {Wiley-Blackwell},
  address   = {Oxford},
  issn      = {1354-1013 (Print)},
  doi       = {10.1111/gcb.12038},
  pages     = {229 -- 240},
  year      = {2012},
  abstract  = {An increasing number of studies have reported on forest declines and vegetation shifts triggered by drought. In the Swiss Rhone valley (Valais), one of the driest inner-Alpine regions, the species composition in low elevation forests is changing: The sub-boreal Scots pine (Pinus sylvestris L.) dominating the dry forests is showing high mortality rates. Concurrently the sub-Mediterranean pubescent oak (Quercus pubescens Willd.) has locally increased in abundance. However, it remains unclear whether this local change in species composition is part of a larger-scale vegetation shift. To study variability in mortality and regeneration in these dry forests we analysed data from the Swiss national forest inventory (NFI) on a regular grid between 1983 and 2003, and combined it with annual mortality data from a monitoring site. Pine mortality was found to be highest at low elevation (below 1000 m a.s.l.). Annual variation in pine mortality was correlated with a drought index computed for the summer months prior to observed tree death. A generalized linear mixed-effects model indicated for the NFI data increased pine mortality on dryer sites with high stand competition, particularly for small-diameter trees. Pine regeneration was low in comparison to its occurrence in the overstorey, whereas oak regeneration was comparably abundant. Although both species regenerated well at dry sites, pine regeneration was favoured at cooler sites at higher altitude and oak regeneration was more frequent at warmer sites, indicating a higher adaptation potential of oaks under future warming. Our results thus suggest that an extended shift in species composition is actually occurring in the pine forests in the Valais. The main driving factors are found to be climatic variability, particularly drought, and variability in stand structure and topography. Thus, pine forests at low elevations are developing into oak forests with unknown consequences for these ecosystems and their goods and services.},
  language  = {en}
}