Fieldwork on biogenic volatile organic compounds
by Riikka Rinnan
Throughout the summer 2013, we measured emissions of biogenic volatile organic compounds (VOCs) in several locations in Greenland (Nuuk, SW Greenland, Zackenberg, NE Greenland, Disko Island, W Greenland) and in northern Finland (Kuusamo and Kilpisjärvi). Emissions of VOCs are affected by climate change, but these compounds also have an effect on the lifetime of greenhouse gases in the atmosphere and thus, they also have an impact on the climate themselves.
The focus of our group is to map the emissions of VOCs and to find out which parameters affect the emission signatures. Emissions have been measured on ecosystem scale from different ecosystem types but also from soil, individual plants and decomposing litter in litter bags. Manipulations include litter additions/removal, increased temperature, reduced light intensity, shortening/extension of the growing season. On Disko Island, we have been working on the snow fence experiment to see how winter warming with and without warming during the growing season and shrub removal affect the emissions. In addition, dark measurements has been performed to see which compounds are emitted in darkness, and 24 hour measurements campaign to see how much, if any, VOCs are emitted during the nightless night of the summer in the Arctic.
In Finland, the measurements have been carried out in two long-term International Tundra EXperiment (ITEX)-sites established in 1994. Both sites have similar set-ups including control, warming, herbivory treatment and herbivory combined with warming. The herbivory treatment simulating reindeer grazing has been done annually since 1994. From individual Vaccinium myrtillus plants both VOCs and CO2-exchange were measured over the growing season. Leaf samples were collected for microscopy.
After the field season the work continues in the laboratory, where leaf structure will be studied. We expect that morphological adaptations in leaves may explain differences in VOC emission spectra from different species. Furthermore, laboratory measurements of VOCs will be performed on litter collected from different localities in Greenland.
The BVOC group: Frida Lindwall, Sarah Hagel Svendsen, Hanna Valolahti, Michelle Scholler, and Riikka Rinnan.
If you want to know more, please contact Riikka Rinnan.