title: Survival of Norway spruce remains higher in mixed stands under a dryer and warmer climate.
abstract: Shifts in tree species distributions caused by climatic change are expected to cause severe losses in the economic value of European forestland. However, this projection disregards potential adaptation options such as tree species conversion, shorter production periods, or establishment of mixed species forests. The effect of tree species mixture has, as yet, not been quantitatively investigated for its potential to mitigate future increases in production risks. For the first time, we use survival time analysis to assess the effects of climate, species mixture and soil condition on survival probabilities for Norway spruce and European beech. Accelerated Failure Time (AFT) models based on an extensive dataset of almost 65,000 trees from the European Forest Damage Survey (FDS)--part of the European-wide Level I monitoring network--predicted a 24% decrease in survival probability for Norway spruce in pure stands at age 120 when unfavorable changes in climate conditions were assumed. Increasing species admixture greatly reduced the negative effects of unfavorable climate conditions, resulting in a decline in survival probabilities of only 7%. We conclude that future studies of forest management under climate change as well as forest policy measures need to take this, as yet unconsidered, strongly advantageous effect of tree species mixture into account.
authors.affiliation: Institute of Forest Management, Center of Life and Food Sciences Weihenstephan, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, Freising, 85354, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Neuner
authors.forename: Axel
authors.initials: A
authors.lastname: Albrecht
authors.forename: Dominik
authors.initials: D
authors.lastname: Cullmann
authors.forename: Friedrich
authors.initials: F
authors.lastname: Engels
authors.forename: Verena C
authors.initials: VC
authors.lastname: Griess
authors.forename: W Andreas
authors.initials: WA
authors.lastname: Hahn
authors.forename: Marc
authors.initials: M
authors.lastname: Hanewinkel
authors.forename: Fabian
authors.initials: F
authors.lastname: Härtl
authors.forename: Christian
authors.initials: C
authors.lastname: Kölling
authors.forename: Kai
authors.initials: K
authors.lastname: Staupendahl
authors.forename: Thomas
authors.initials: T
authors.lastname: Knoke
mesh_terms: D044822:Biodiversity; D057231:Climate Change; D003247:Conservation of Natural Resources; D055864:Droughts; D029964:Fagus / Q000502:physiology*; D065928:Forests; D005858:Germany; D006358:Hot Temperature; D008136:Longevity; D028222:Picea / Q000502:physiology*
keywords: climate effects; forest management; risk; soil conditions; survival probability; tree species mixture