title: Change of plant phenophases explained by survival modeling.
abstract: It is known from many studies that plant species show a delay in the timing of flowering events with an increase in latitude and altitude, and an advance with an increase in temperature. Furthermore, in many locations and for many species, flowering dates have advanced over the long-term. New insights using survival modeling are given based on data collected (1970-2010) along a 3000-km long transect from northern to eastern central Europe. We could clearly observe that in the case of dandelion (Taraxacum officinale) the risk of flowering time, in other words the probability that flowering occurs, is higher for an earlier day of year in later decades. Our approach assume that temperature has greater influence than precipitation on the timing of flowering. Evaluation of the predictive power of tested models suggests that Cox models may be used in plant phenological research. The applied Cox model provides improved predictions of flowering dates compared to traditional regression methods and gives further insights into drivers of phenological events.
authors.affiliation: Department of Plant Systematics, Ecology and Theoretical Biology, Eötvös Loránd University, H-1117, Budapest, Hungary. barbara.a.templ@gmail.com.
authors.forename: Barbara
authors.initials: B
authors.lastname: Templ
authors.affiliation: Statistics Austria, A-1110, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fleck
authors.affiliation: Department of Statistics and Mathematical Methods in Economics, Vienna University of Technology, A-1040, Vienna, Austria.|Zurich University of Applied Sciences, Institute of Data Analysis and Process Design, CH-8400, Winterthur, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Templ
mesh_terms: D005060:Europe; D035264:Flowers / Q000502:physiology*; D053208:Kaplan-Meier Estimate; D016016:Proportional Hazards Models; D011891:Rain; D012621:Seasons; D031205:Taraxacum / Q000502:physiology*; D013696:Temperature
keywords: Biogeographical regions of Europe; Cox model with time dependent covariates; Taraxacum officinale; Timing of flowering