PARENT SESSION
Contributed Oral Session 121: Freshwater Wetlands
Thursday, August 11, 8:00 AM - 11:30 AM, Meeting Room 520 C, Level 5, Palais des congrès de Montréal
The response of four Sphagnum species to water level and temperature.
Robroek, Bjorn*,1, Limpens, Juul1, Schouten, Matthijs1, 2, 1 Wageningen University, Wageningen, The Netherlands2 State Forestry Service, Driebergen, The Netherlands
ABSTRACT- Bryophytes from the genus Sphagnum play a crucial role in the ecology of raised bogs; they regulate the hydrological conditions to a high degree and are largely responsible for the primary production. The extent to which these bryophytes influence their environment, however, differs among species. Effects of climate change, such as changing rates of precipitation and rising temperatures, may affect the species composition in bogs, and ultimately the functioning of the whole ecosystem. We investigated the effects of two temperatures and two water tables on evaporation, water content and production in four Sphagnum species that differ in their geographic distribution over Europe: S. magellanicum and S. rubellum extend further southward than S. fuscum and S. imbricatum. Volumetric water content and evaporation of S. magellanicum and S. rubellum decreased with the water table, together with decreased biomass production of S. magellanicum. For S. fuscum and S. imbricatum we found no differences between the water tables. Temperature enhanced dry weight production of both S. magellanicum and S. rubellum, but S. fuscum and S. imbricatum remained unaffected. On average, biomass production of S. magellanicum was three times lower than that of the other species. Our results show that the effects of global climate change may differ between Sphagnum species. This may result in changes in important ecosystem processes such as water loss and production. We conclude that species composition and changes therein should be taken into account when evaluating global climate change effects on raised bog ecosystems.
Key words: Global change, Peatlands, Sphagnum, Production