Events hidden in winter warming: Effects of recurrent soil freeze-thaw cycles on ecosystem functions in the temperate zone
Zusammenfassung der Projektergebnisse
Winter air temperatures are projected to increase in the temperate zone, whereas snow cover is projected to decrease, leading to more extreme soil temperature variability and potentially to the complete absence of soil frost in formerly cold-temperate ecosystems. Here, we ran three field experiments exploring the ecological importance of (1) increased winter soil temperature variability, (2) a prolonged winter warm spell, and (3) complete absence of soil frost. All three subprojects comprised experimental evidence for the high ecological importance of winter climate change. In general, the plant responses to the applied winter climate change scenarios were species specific. Species composition, on the other hand, proved highly influential for cycling of nitrogen and carbon. Understanding the nitrogen and carbon cycle under changing climate therefore requires profound knowledge on concomitantly altered plant performance. With regard to the projected climate change, increasing variability in winter soil temperatures will be the rule, not an exception in the temperate zone. The observed transient effects in community composition might therefore translate into altered species distributions or shifts in community compositions in the long run despite high initial resilience in response to one single unusual winter. Our results further imply increased risk for frost damage and for nitrogen leaching due to increased winter soil temperature variability at colder temperate sites than at warmer temperate sites. The latter finding emphasizes the importance of multi-site experiments for the generation of generalizable results from field experiments.
Projektbezogene Publikationen (Auswahl)
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(2013): Absence of soil frost affects plant soil interactions in temperate grasslands. Plant and Soil 371: 559-572
Schuerings J, Grant K, Malyshev A, Beierkuhnlein C, Jentsch A, Kreyling J
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(2014) Winter warming pulses differently afftect plant performance in temperate heathland and grassland communities. Ecological Research 29: 561-570
Schürings J, Jentsch A, Kreyling J
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(2014): Recurrent winter warming pulses enhance nitrogen cycling and soil biotic activity in temperate heathland and grassland mesoscosm. In Special Issue: Climate extremes and biogeochemical cycles in the terrestrial biosphere: impacts and feedbacks across scales. Biogeosciences 11: 7051-7060
Schürings J, Jentsch A, Hammerl V, Lenz K, Kreyling J
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Nitrogen leaching is enhanced after a winter warm spell but mainly controlled by vegetation composition in temperate zone mesocosms. Plant and Soil (published online 06/07/2015)
Kreyling J, Schürings J, Malyshev A, Vogt L, Werner, CH, Jentsch A
