 |
| Titel |
Short term response of a peatland to warming and drought – climate manipulation experiment in W Poland |
| VerfasserIn |
Radoslaw Juszczak, Bogdan Chojnicki, Marek Urbaniak, Jacek Leśny, Hanna Silvennoinen, Mariusz Lamentowicz, Anna Basińska, Maciej Gąbka, Marcin Stróżecki, Mateusz Samson, Dominika Łuców, Damian Józefczyk, Mathias Hoffmann, Janusz Olejnik |
| Konferenz |
EGU General Assembly 2016
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250133895
|
| Publikation (Nr.) |
 EGU/EGU2016-14558.pdf |
|
|
|
|
|
| Zusammenfassung |
| Central European peatlands are highly vulnerable as potential sources of carbon (C) to the
atmosphere under anticipated climate changes, namely warming and drought (Fenner &
Freeman 2011). We carried out a field manipulation experiment at Rzecin peatland in Poland
to assess how those changes impact carbon balance, vegetation and water chemistry. The field
site consists of three times replicated treatments (control, CO; simulated warming,
W; prolonged drought, D and warming & drought, W+D). Temperature (T) was
increased year around with infrared heaters (400W × 4 per site, approx. 60 W⋅m−2
addition of LW radiation, Kimball 2005) and precipitation was reduced with automatic
curtain during growth seasons at night. The manipulation was successful yielding
up to 0.4 oC and 1.0 oC T increases in air (30 cm height) and soil (5 cm depth),
respectively, as well as a 35 % lower precipitation (in 2015). To study the C exchange we
developed an automatic mobile platform for measuring CO2/CH4/H2O fluxes (LGR) as
well as for 13CO2 and 13CH4 fluxes (PICARRO CRDS G2201-i) with dynamic
ecosystem chambers (for NEE and Reco) and for simultaneous measurements of surface
optical properties. Gap filling of the fluxes was done according to Hoffmann et al.
2015.
In the very dry 2015, Rzecin peatland was a net source of CO2to the atmosphere (80
gC⋅m−2yr−1). Warming and drought considerably diminished the source strength (7
gC⋅m−2yr−1at the W+D site), due to lower cumulative respiration (Reco the smallest, 610 gC
m−2yr−1, at W+D site). The highest CO2 emissions were measured from the site that was
only warmed (W site, Reco 680 gC⋅m−2yr−1), emphasizing the importance of drought in
inhibiting respiration. Temperature increase also provoked the productivity (highest GPP at
W site, -620 gC⋅m−2yr−1), while drought yielded the lowest productivity (lowest GPP at D
site, -550 gC⋅m−2yr−1). Different vegetation parameters further support the C exchange
estimates. Generally, warmer conditions led to increases in NDVI and LAI, whilst the site
exposed to only drought exhibited the lowest LAI. Warming shifted the vegetation species
composition by promoting vascular plants (mainly Carex rostrata and C. limosa), which
result also correlates positively with nutrient (Ptot, Mn, F, Na, Zn) availability in the peat
water.
Here, we report short-term responses to increased temperature and diminished
precipitation, showing that the combination of these to stressors leads to very different
scenario than their individual impacts. Our results further emphasize the need for
long term records from field manipulation site on peatland response to climate
changes.
The Research was co-founded by the Polish National Centre for Research and
Development within the Polish-Norwegian Research Programme within the WETMAN
project (Central European Wetland Ecosystem Feedbacks to Changing Climate – Field
Scale Manipulation, Project ID: 203258, contract No. Pol-Nor/203258/31/2013
(www.wetman.pl).
References
Fenner N., Freeman Ch. (2011). Nature Geoscience, 4, 895-900
Hoffmann M., et al. (2015). Agricultural and Forest Meteorology, 200, 30-45
Kimball BA. (2005). Global Change Biology, 11, 2041-2056 |
|
|
|
|
|
|