Final progress report ARWSL EPFL ECOS Andy Siegenthaler

Final progress report AR-WSL, EPFL ECOS Andy Siegenthaler Emanuela Samaritani, Edward Mitchell, Alexandre Buttler RECIPE meeting Aberdeen 29 -31 May 2006

Growing keystone species experiment June 2004 -July 2005 WP II A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006

D 20, D 21, D 23 Basal respiration WPII Effects of different keystone species on CO 2 and CH 4 production and emissions at various water levels. Gas CO 2 Water table E. angustifolium E. vaginatum Low 0 0 Intermediate + ++ CO 2 CH 4 CH 4 High Low Intermediate High Gas CO 2 Water table E. angustifolium E. vaginatum Low 0 0 Intermediate 0 0 CO 2 CH 4 High Low Intermediate High 0 0 0 0 0 +° 0 0 0 S. fallax 0 0 0 H 3 S. fallax 0 0 0 H 5 S. fallax 0 0 0 A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006 H 7

D 20, D 21, D 23 Resumed basal respiration WPII Design plot for the CO 2 production (µmol. d-1. dm-3) 260 H 3 240 220 200 Low 180 EA Intermed. 160 EV S High CT 140 H 5 120 H 7 WT Species Depth Factors A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006

D 20, D 21, D 23 Resumed basal respiration WPII High CT Intermed. EA 0. 1 0. 2 0. 3 H 7 S EV Low H 5 0. 0 CH 4 production (umol. d-1. dm-3) 0. 4 Design plot for the CH 4 production H 3 WT Species Depth Factors A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006

WPII: Active type II methanotrophs (FISH) in growing Sphagnum (H 3) DAPI FISH/DAPI D 11, D 14, D 20 A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006

Litter decomposition experiment August 2004 - November 2005 WP III A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006

D 16, D 20 Litter mass-loss (% d. wt/d. wt) EA EV Litter species S EA EV S Low Interm. High Litter species X water level A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006

D 20, D 21, D 23 In-situ surface fluxes (WPIII) 40 CH 4 30 CH 4 flux (µmol. d-1. m-2) CO 2 35 25 20 15 10 5 0 Low Interm. High Water level A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006

D 20, D 21, D 23 Litter type effect on CO 2 and CH 4 production A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006

D 20, D 21, D 23 Litter effect on basal respiration (WPIII) B. Effects of different litter types on on CO 2 and CH 4 production and emissions at various water levels. In all cases C 02 production is decreasing and CH 4 production to increase with decreasing water level. Gas CO 2 Water table Low E. angustifolium E. vaginatum 0 0 CO 2 Intermediate 0 0 0 CO 2 High + + 0 CH 4 Low 0 0 ++ CH 4 Intermediate 0 0 0 CH 4 High 0 0 0 Gas Water table CO 2 Low 0 0 0 CO 2 Intermediate 0 +° 0 CO 2 High - 0 0 CH 4 Low 0 0 0 CH 4 Intermediate 0 0 0 CH 4 High 0 0 0 Gas Water table CO 2 Low -- -- -° CO 2 Intermediate 0 0 0 CO 2 High 0 0 0 CH 4 Low Intermediate High 0 0 -0 0 E. angustifolium E. vaginatum S. fallax 0 H 4 S. fallax H 5 S. fallax H 7

D 20, D 21, D 23 Resumed basal respiration (WP III) Design plot for CO 2 production 600 Low 500 EV Interm. High CT S EA H 5 400 CO 2 production (umol. d-1. dm-3) 700 H 3 H 7 WT Species Depth Factors A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006

D 20, D 21, D 23 Resumed basal respiration (WP III) 8 10 H 7 High 2 4 6 CT Interm. EA EV S Low 0 CH 4 production (umol. d-1. dm-3) 12 Design plot for CH 4 production H 5 WT Species Factors H 3 Depth

D 20, D 21, D 23 Resumed surface respiration WPIII 5 Low CT 3 4 S Interm. EA EV 2 CO 2 production (mmol. d-1. m 2) 6 Design plot for CO 2 production High Water_level Litter_species Factors

D 20, D 21, D 23 Resumed surface respiration WPII 30 32 High 26 28 S EA EV CT 24 CH 4 production (µmol. d-1. m 2) 34 Design plot for CH 4 production Low Intermed. Water_level Litter_species Factors

WPIII: Active type II methanotrophs in Sphagnum litter 2 e+7 2 e+6 2 e+7 DAPI (ind. /g f. wt) Type II Methanotrophs (ind. /g f. wt) 3 e+6 2 e+7 2 e+6 1 e+7 1 e+6 5 e+5 0 e+0 Low Interm. Water level High 0 e+0 Low Interm. Water level D 11, D 14, D 20 A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006 High

D 11, D 14, D 16, D 20, D 21, D 23 Conclusions • In a situation with low water level, the presence of any kind of litter decreases the CO 2 production at -35 cm. • In a situation with low water level, the presence of any kind of litter decreases the methane production at -35 cm. • Under intermediate water level conditions Sphagnum litter drastically decreased the in-situ methane flux. • The Sphagnum litter turnover time is higher under intermediate water level conditions. • There are more methanotrophs where more methane is produced! ; -) • The surface CO 2 fluxes in WPIII are strongly positively correlated to the basal respiration at -15 cm depth and negatively correlated to the methanogenesis at -15 cm depth. And inversely! • The surface CH 4 fluxes are negatively correlated to the CO 2 production at -7. 5 cm depth. A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006

Achievements during 2005/06 Andy (A), Emanuela (Em) • • • Em: terminated the surface gas flux measurements (NEE, Rtot, PG) at la Chuax-d’Abel. A&Em: surface methane fluxes Chaux-d’Abel during 2005. FISH hybridisation for WPI - methodological improvement and counting of methanogens and eubacteria. Em: finished her master’s research and graduated in May 2006. A+all: WPII sampling and dispatching in July 2005. A&Em: WPIII surface fluxes, harvesting, sampling, dispatching, incubations in autumn 2005. A: WPII basal respiration for Baupt samples (monovette). A: re-analysed delta 13 C-CO 2 and delta 13 C-CH 4 of the surface samples using a supplementary cryogenic step to improve accuracy for methane. A: WPIII surface samples basal respiration for the short term decomposition experiment. A: recounting whole community in WPI with inverted microscopic (total 18 from the 27 samples. A&Em: WPII (FR): basal respiration (monovette) and FISH hybridisations for methanotrophs. A. Siegenthaler, RECIPE meeting Aberdeen 29 -31 May 2006