title: Meteorological Drivers of Extremes in Daily Stem Radius Variations of Beech, Oak, and Pine in Northeastern Germany: An Event Coincidence Analysis.
abstract: Observed recent and expected future increases in frequency and intensity of climatic extremes in central Europe may pose critical challenges for domestic tree species. Continuous dendrometer recordings provide a valuable source of information on tree stem radius variations, offering the possibility to study a tree's response to environmental influences at a high temporal resolution. In this study, we analyze stem radius variations (SRV) of three domestic tree species (beech, oak, and pine) from 2012 to 2014. We use the novel statistical approach of event coincidence analysis (ECA) to investigate the simultaneous occurrence of extreme daily weather conditions and extreme SRVs, where extremes are defined with respect to the common values at a given phase of the annual growth period. Besides defining extreme events based on individual meteorological variables, we additionally introduce conditional and joint ECA as new multivariate extensions of the original methodology and apply them for testing 105 different combinations of variables regarding their impact on SRV extremes. Our results reveal a strong susceptibility of all three species to the extremes of several meteorological variables. Yet, the inter-species differences regarding their response to the meteorological extremes are comparatively low. The obtained results provide a thorough extension of previous correlation-based studies by emphasizing on the timings of climatic extremes only. We suggest that the employed methodological approach should be further promoted in forest research regarding the investigation of tree responses to changing environmental conditions.
authors.affiliation: Research Domain IV-Transdisciplinary Concepts and Methods, Potsdam Institute for Climate Impact ResearchPotsdam, Germany; Institute of Earth and Environmental Science, University of PotsdamPotsdam, Germany.
authors.forename: Jonatan F
authors.initials: JF
authors.lastname: Siegmund
authors.affiliation: Thünen Institute of Forest Ecosystems Eberswalde, Germany.
authors.forename: Tanja G M
authors.initials: TG
authors.lastname: Sanders
authors.affiliation: Department 5 Geoarchives, Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences Potsdam, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Heinrich
authors.affiliation: Institute of Botany and Landscape Ecology, University of Greifswald Greifswald, Germany.
authors.forename: Ernst
authors.initials: E
authors.lastname: van der Maaten
authors.affiliation: Department 5 Geoarchives, Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences Potsdam, Germany.
authors.forename: Sonia
authors.initials: S
authors.lastname: Simard
authors.affiliation: Department 5 Geoarchives, Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences Potsdam, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Helle
authors.affiliation: Research Domain IV-Transdisciplinary Concepts and Methods, Potsdam Institute for Climate Impact Research Potsdam, Germany.
authors.forename: Reik V
authors.initials: RV
authors.lastname: Donner
keywords: climate extremes; dendrometer measurements; event coincidence analysis; growth response