TY - JOUR

T1 - Non-methane biogenic volatile organic compound emissions from boreal peatland microcosms under warming and water table drawdown

AU - Faubert, P

AU - Tiiva, P

AU - Nakam, TA

AU - Holopainen, JK

AU - Holopainen, T

AU - Rinnan, Riikka

PY - 2011

Y1 - 2011

N2 - Abstract Boreal peatlands have significant emissionsof non-methane biogenic volatile organiccompounds (BVOCs). Climate warming is expectedto affect these ecosystems both directly, with increasingtemperature, and indirectly, through water tabledrawdown following increased evapotranspiration.We assessed the combined effect of warming andwater table drawdown on the BVOC emissions fromboreal peatland microcosms. We also assessed thetreatment effects on the BVOC emissions from thepeat soil after the 7-week long experiment. Emissionsof isoprene, monoterpenes, sesquiterpenes, otherreactive VOCs and other VOCs were sampled usinga conventional chamber technique, collected onadsorbent and analyzed by GC–MS. Carbon emittedas BVOCs was less than 1% of the CO2 uptake andup to 3% of CH4 emission. Water table drawdownsurpassed the direct warming effect and significantlydecreased the emissions of all BVOC groups. Onlyisoprene emission was significantly increased bywarming, parallel to the increased leaf number of thedominant sedge Eriophorum vaginatum. BVOCemissions from peat soil were higher under thecontrol and warming treatments than water tabledrawdown, suggesting an increased activity of anaerobicmicrobial community. Our results suggest thatboreal peatlands could have concomitant negativeand positive radiative forcing effects on climatewarming following the effect of water table drawdown.The observed decrease in CH4 emission causesa negative radiative forcing while the increase in CO2emission and decrease in reactive BVOC emissions,which could reduce the cooling effect induced by thelower formation rate of secondary organic aerosols,both contribute to increased radiative forcing.

AB - Abstract Boreal peatlands have significant emissionsof non-methane biogenic volatile organiccompounds (BVOCs). Climate warming is expectedto affect these ecosystems both directly, with increasingtemperature, and indirectly, through water tabledrawdown following increased evapotranspiration.We assessed the combined effect of warming andwater table drawdown on the BVOC emissions fromboreal peatland microcosms. We also assessed thetreatment effects on the BVOC emissions from thepeat soil after the 7-week long experiment. Emissionsof isoprene, monoterpenes, sesquiterpenes, otherreactive VOCs and other VOCs were sampled usinga conventional chamber technique, collected onadsorbent and analyzed by GC–MS. Carbon emittedas BVOCs was less than 1% of the CO2 uptake andup to 3% of CH4 emission. Water table drawdownsurpassed the direct warming effect and significantlydecreased the emissions of all BVOC groups. Onlyisoprene emission was significantly increased bywarming, parallel to the increased leaf number of thedominant sedge Eriophorum vaginatum. BVOCemissions from peat soil were higher under thecontrol and warming treatments than water tabledrawdown, suggesting an increased activity of anaerobicmicrobial community. Our results suggest thatboreal peatlands could have concomitant negativeand positive radiative forcing effects on climatewarming following the effect of water table drawdown.The observed decrease in CH4 emission causesa negative radiative forcing while the increase in CO2emission and decrease in reactive BVOC emissions,which could reduce the cooling effect induced by thelower formation rate of secondary organic aerosols,both contribute to increased radiative forcing.

U2 - 10.1007/s10533-011-9578-y

DO - 10.1007/s10533-011-9578-y

M3 - Journal article

VL - 106

SP - 503

EP - 516

JO - Biogeochemistry

JF - Biogeochemistry

SN - 0168-2563

IS - 3

ER -