title: Local adaptations to frost in marginal and central populations of the dominant forest tree Fagus sylvatica L. as affected by temperature and extreme drought in common garden experiments.
abstract: Local adaptations to environmental conditions are of high ecological importance as they determine distribution ranges and likely affect species responses to climate change. Increased environmental stress (warming, extreme drought) due to climate change in combination with decreased genetic mixing due to isolation may lead to stronger local adaptations of geographically marginal than central populations. We experimentally observed local adaptations of three marginal and four central populations of Fagus sylvaticaL., the dominant native forest tree, to frost over winter and in spring (late frost). We determined frost hardiness of buds and roots by the relative electrolyte leakage in two common garden experiments. The experiment at the cold site included a continuous warming treatment; the experiment at the warm site included a preceding summer drought manipulation. In both experiments, we found evidence for local adaptation to frost, with stronger signs of local adaptation in marginal populations. Winter frost killed many of the potted individuals at the cold site, with higher survival in the warming treatment and in those populations originating from colder environments. However, we found no difference in winter frost tolerance of buds among populations, implying that bud survival was not the main cue for mortality. Bud late frost tolerance in April differed between populations at the warm site, mainly because of phenological differences in bud break. Increased spring frost tolerance of plants which had experienced drought stress in the preceding summer could also be explained by shifts in phenology. Stronger local adaptations to climate in geographically marginal than central populations imply the potential for adaptation to climate at range edges. In times of climate change, however, it needs to be tested whether locally adapted populations at range margins can successfully adapt further to changing conditions.
authors.affiliation: Biogeography, BayCEER, University of Bayreuth Bayreuth, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Kreyling
authors.affiliation: Geoecology/Physical Geography, University of Landau Landau, Germany.
authors.forename: Constanze
authors.initials: C
authors.lastname: Buhk
authors.affiliation: Disturbance Ecology, BayCEER, University of Bayreuth Bayreuth, Germany.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Backhaus
authors.affiliation: Landscape Ecology, University of Greifswald Greifswald, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Hallinger
authors.affiliation: Bavarian Institute for Forest Seeding and Planting (ASP) Teisendorf, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Huber
authors.affiliation: Geoecology/Physical Geography, University of Landau Landau, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Huber
authors.affiliation: Disturbance Ecology, BayCEER, University of Bayreuth Bayreuth, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Jentsch
authors.affiliation: Bavarian Institute for Forest Seeding and Planting (ASP) Teisendorf, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Konnert
authors.affiliation: Bavarian Institute for Forest Seeding and Planting (ASP) Teisendorf, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Thiel
authors.affiliation: Landscape Ecology, University of Greifswald Greifswald, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Wilmking
authors.affiliation: Biogeography, BayCEER, University of Bayreuth Bayreuth, Germany.
authors.forename: Carl
authors.initials: C
authors.lastname: Beierkuhnlein
keywords: Common garden experiment; European beech; frost; local adaptation; minimum temperature; mortality