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RECIPE M ü nchen Progress meeting 17-20/05/2005. UK progress Rebekka Artz Stephen Chapman Colin Campbell. I. WP01 UK Field site data. Middlemuir Moss, between Strichen and New Pitsligo, NE Scotland
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RECIPE München Progress meeting 17-20/05/2005 UK progress Rebekka Artz Stephen Chapman Colin Campbell
I. WP01 UK Field site data • Middlemuir Moss, between Strichen and New Pitsligo, NE Scotland • Data collection finished, modelling in progress – meeting with Mika and Harri (20-22/04) to kick this off
Dark CO2 production Bare peat, total respiration models (r2 = 0.6 (WT), 0.82 (T @ -5 cm)
CO2 fluxes 2 – PGCO2 E. angustifolium + S. auric. collar, r2 = 0.72
Modelling problems • Not enough data to model per collar, trying to overcome this by pooling data from replicate collars (Mika found that this doesn’t always work well…) • Rtot modelling produces very low r2 values – a lot of data had to be excluded as either missed dark measurements or negative dark fluxes • PGCO2 modelling ok, but lack of LAI data forces use of other seasonality index, both air and -5 cm temps seem to work ok
II. WP2 Progress • Problems with negative dark fluxes (i.e. CO2 uptake) since july 2004 – these appear to have been at least partially caused by our large chambers and an overly sensitive IRGA system (when checking data all these fluxes had low r2 values, i.e <0.8) • Data collection since new (much smaller) chambers/PPsystems IRGA (february 2005) much more stable and no more uptake in the dark! • Methane analyses have been hampered by GC breakdown at the start of this year and lack of tech support (back log/loss of 2 or 3 sampling points this year). • Data analysis lagging behind….will try to keep running the remaining replicates beyond june harvest!
Further work: • 1st harvest starting 6.06 (pending decision) • Clare Trinder is using the field site for litter bag experiments, 5 species (E. ang/vag; S. subnitens?; Calluna vulgaris, spruce) and will look at decomposition rates and microbial diversity in the litter bags. Litter quantities in the field estimates by traps around small plants • Also being set up by Clare: decomposition experiments with added live plants, also involving 14C labelling of the plants to chase carbon
Fungal community structure as Indicators of change? FR CH FI • fungal ITS clone library from SC set , 150 clones sequenced. Most sequences showed < 70 % homology with any sequence in Genbank. Paper is now in prep. EARLY LATE
12 Saccharomyces ? (60) 851 Cordyceps bassiana (99) 164 Cortinarius sp (90) 312 Sebacina endomycorrhiza (88)
476 Hymenoscyphus (75) 562 Malassezia globosa (98) 625 + 637 Mycena (92)
Includes Polyporales & Thelephorales Chaeto/Lasiosphaera & Cercophora Hymenoscyphus etc, & Peziculales Cordyceps, Cephalosporium, Fusarium etc. Exidiopsis etc/ Cryptococcus etc.
IV. Community level physiological profiling • paper submitted to Environmental Microbiology detailing the adapted peat MicroResp method and validation data • validated the method in three experiments: 1) optimum incubation time 2) sample moisture content and 3) sample ageing due to sample transport and storage • needs to be re-submitted to EM (hopefully mid june)
CVA scores SD (n = 3) of Moss (filled squares), Decaying moss (open squares), Newly formed peat (filled triangles) and Old catotelm peat (open triangles) after 4h (plot A), 20h (Plot B), 48h (Plot C) and 120h (Plot D) of incubation.
Effect of adjustment of moisture content on CLPP-SIP patterns. Peat samples were adjusted to 80 (filled squares), 85 (open squares), 90 (filled triangles) and 95 % GWC (open triangles). Data show the mean CV scores SD (n = 3)
Samples of different degrees of decomposition were stored at 4ºC for 7 d (filled squares), 28 d (open squares), 49 d (filled triangles), 70 d (open triangles) and 103 d (open diamonds). Data show the mean CV scores SD (n = 3)
V. FTIR and a request… • Now in the process of working up the WP1 FTIR data. We found some interesting patterns in the carbohydrate signal region that may tie up with the vegetation structure – our FTIR specialist would be very interested in some clean homocellulose or other (sugar?) fractions for FTIR…. • another region indicating free acids ties up closely with pH values in the SC set, more environmental data are needed to check this for all WP1 data • a combination of the free acid, carbohydrate and ‘lignin’-marker regions may be useful as an index for humification – still in progress