Growth and community responses of alpine dwarf shrubs to in situ CO2 enrichment and soil warming
Article first published online: 19 APR 2011
© 2011 WSL Institute for Snow and Avalanche Research SLF. New Phytologist © 2011 New Phytologist Trust
Volume 191, Issue 3, pages 806–818, August 2011
How to Cite
Dawes, M. A., Hagedorn, F., Zumbrunn, T., Handa, I. T., Hättenschwiler, S., Wipf, S. and Rixen, C. (2011), Growth and community responses of alpine dwarf shrubs to in situ CO2 enrichment and soil warming. New Phytologist, 191: 806–818. doi: 10.1111/j.1469-8137.2011.03722.x
- Issue published online: 20 JUL 2011
- Article first published online: 19 APR 2011
- Received: 3 February 2011, Accepted: 13 March 2011
- alpine treeline;
- dwarf shrub;
- elevated CO2;
- Empetrum hermaphroditum (crowberry);
- free air CO2 enrichment (FACE);
- soil warming;
- Vaccinium gaultherioides (northern bilberry);
- Vaccinium myrtillus (bilberry)
- •Rising CO2 concentrations and the associated global warming are expected to have large impacts on high-elevation ecosystems, yet long-term multifactor experiments in these environments are rare.
- •We investigated how growth of dominant dwarf shrub species (Vaccinium myrtillus, Vaccinium gaultherioides and Empetrum hermaphroditum) and community composition in the understorey of larch and pine trees responded to 9 yr of CO2 enrichment and 3 yr of soil warming at the treeline in the Swiss Alps.
- •Vaccinium myrtillus was the only species that showed a clear positive effect of CO2 on growth, with no decline over time in the annual shoot growth response. Soil warming stimulated V. myrtillus growth even more than elevated CO2 and was accompanied by increased plant-available soil nitrogen (N) and leaf N concentrations. Growth of Vaccinium gaultherioides and E. hermaphroditum was not influenced by warming. Vascular plant species richness declined in elevated CO2 plots with larch, while the number of moss and lichen species decreased under warming.
- •Ongoing environmental change could lead to less diverse plant communities and increased dominance of the particularly responsive V. myrtillus in the studied alpine treeline. These changes are the consequence of independent CO2 and soil warming effects, a result that should facilitate predictive modelling approaches.