The shift in plant species composition in a subarctic mountain birch forest floor due to climate change would modify the biogenic volatile organic compound mission profile

TY - JOUR

T1 - The shift in plant species composition in a subarctic mountain birch forest floor due to climate change would modify the biogenic volatile organic compound mission profile

AU - Faubert, Patrick

AU - Tiiva, Päivi

AU - Michelsen, Anders

AU - Rinnan, Åsmund

AU - Ro-Poulsen, Helge

AU - Rinnan, Riikka

PY - 2012/3

Y1 - 2012/3

N2 - Background and aims: Mountain birch forests dominate in the Subarctic but little is known of their non-methane biogenic volatile organic compound (BVOC) emissions. The dwarf shrubs Empetrum hermaphroditum, Vaccinium myrtillus and Vaccinium uliginosum co-dominate in the forest floors of these forests. The abundance of these three dwarf shrubs relative to each other could be affected by climate warming expected to increase nutrient availability by accelerating litter decomposition and nutrient mineralization. We 1) compared the BVOC emission profiles of vegetation covers dominated by E. hermaphroditum and V. myrtillus plus V. uliginosum in a subarctic mountain birch forest floor, 2) distinguished the BVOCs emitted from plants and soil and 3) measured how the BVOC emissions from the different vegetation covers differed under darkness. Methods: BVOCs were sampled during two growing seasons using a conventional ecosystem chamber-based method, collected on adsorbent and analyzed with gas chromatography-mass spectrometry. Results: High abundance of E. hermaphroditum increased the sesquiterpene emissions. Soil released fewer different BVOCs than controls (i. e. natural vegetation) but the total emission rates were similar. Darkness did not affect the emissions. Carbon emitted as BVOCs was less than 0.2% of the CO 2 exchange. Conclusions: Our results suggest that sesquiterpene emissions from subarctic mountain birch forest floors would be reduced following an increased abundance of V. myrtillus and V. uliginosum with climate change because these species respond rapidly to increased nutrient availability.

AB - Background and aims: Mountain birch forests dominate in the Subarctic but little is known of their non-methane biogenic volatile organic compound (BVOC) emissions. The dwarf shrubs Empetrum hermaphroditum, Vaccinium myrtillus and Vaccinium uliginosum co-dominate in the forest floors of these forests. The abundance of these three dwarf shrubs relative to each other could be affected by climate warming expected to increase nutrient availability by accelerating litter decomposition and nutrient mineralization. We 1) compared the BVOC emission profiles of vegetation covers dominated by E. hermaphroditum and V. myrtillus plus V. uliginosum in a subarctic mountain birch forest floor, 2) distinguished the BVOCs emitted from plants and soil and 3) measured how the BVOC emissions from the different vegetation covers differed under darkness. Methods: BVOCs were sampled during two growing seasons using a conventional ecosystem chamber-based method, collected on adsorbent and analyzed with gas chromatography-mass spectrometry. Results: High abundance of E. hermaphroditum increased the sesquiterpene emissions. Soil released fewer different BVOCs than controls (i. e. natural vegetation) but the total emission rates were similar. Darkness did not affect the emissions. Carbon emitted as BVOCs was less than 0.2% of the CO 2 exchange. Conclusions: Our results suggest that sesquiterpene emissions from subarctic mountain birch forest floors would be reduced following an increased abundance of V. myrtillus and V. uliginosum with climate change because these species respond rapidly to increased nutrient availability.

U2 - 10.1007/s11104-011-0989-2

DO - 10.1007/s11104-011-0989-2

M3 - Journal article

SN - 0032-079X

VL - 352

SP - 199

EP - 215

JO - Plant and Soil

JF - Plant and Soil

IS - 1-2

ER -