Description
Predicted climate warming may lead to changes of the highly vulnerable wetland ecosystems by changing the hydrology, biodiversity, plant and microbial structure and therefore the overall C dynamics. The objective is to assess the impact of predicted increased temperature and reduced precipitation on peatland. The outputs will increase our understanding of potential climate change impact on peatland ecosystem functioning. This would support: the global estimations of greenhouse gases exchange on peatlands exposed to extreme conditions; knowledge about potential biodiversity changes and their impact on C balances; knowledge about the usefulness of remote sensing in assessment of climate related impact on peatland vegetation. This project will benefit the researchers and politicians dealing with climate change issues. The bilateral relations between project partners will be strengthened by collaborative laboratory analyses, workshops and common papers in peer-review journals. Beside publications, the established long term cooperation bridge between Polish and Norwegian institution will be the most important achievement of the partnership.
Summary of project results
Peatlands are highly vulnerable ecosystems, due to their potential to be major carbon (C) sources to the atmosphere after anticipated changes in climate. In situ climate manipulation experiment was carried out within the WETMAN project (2013-2017) in Poland at a Sphagnum peatland. We studied the impacts of increased peat temperature and reduced precipitation on: 1) C exchange 2) stability and allocation of the C 3) radiation balance 4) biodiversity and microbial activity 5) biogeochemistry 6) structure of vegetation and primary production, 6) optical and biophysical properties of vegetation. WETMAN site consisted of four blocks: control; warming (W) reduced precipitation and warming (W+RP) & reduced precipitation(RP). The site and the unique climate manipulation infrastructure were developed in 2014 and active manipulations were applied in 2015-2016. We measured C fluxes with a novel automatic closed chamber system developed in the project (patent application submitted in 2017). Warming increased both emission (Reco) and assimilation of CO2 (GPP). Combined effect of W+RP, resulted in decreased net CO2 assimilation (NEE) in both years, specifically due to reduced Reco. RP had no effect on Reco, but significantly reduced GPP. Climate manipulations had no significant effects on C flow and C allocation to vegetation, as measured with 13C labelling methods. Results from the labelling experiment mildly indicate that seasonal differences in C turnover may be of higher importance than those caused by short term climate manipulations. Manipulation increased CH4 fluxes by 34%, mainly due to temperature raise, but also due to increase in the coverage of vascular plants. NEE, GPP, but also the net carbon ecosystem balance and greenhouse gas balances were significantly correlated with NDVI index, which highlighted the potential of remote sensing in assessing C balances from peatlands and extrapolation of our results. The abundance of vascular plants, mainly Carex rostrata substantially changed in relation to warming. Manipulations also had a clear effect on microorganisms. Testate amoeba were the most sensitive for manipulation and reacts stronger to mix manipulation of W+RP. This result confirmed that testate amoeba can be a good proxy of peatland dryness. W+RP also clearly affected the biogeochemistry of the peatland.
Summary of bilateral results
Partnership with Norwegian partner was crucial and important for our group from many reasons; 1) without Norwegian partner we would never apply for the project 2) without partnership and involvement of Norwegian world-wide recognized scientists the quality of the proposal would never be so high, hence the chance to receive funds would also be smaller 3) we would never perform isotopic studies within the project, and as the effect we would not be able to assess the carbon turnover, allocation and flux partitioning, which was one of the main objective of the project. Currently, thanks to the partnership with NIBIO researchers we are able to apply pulse chase labeling technique (PCL) by ourselves, as PULS researchers and PhD students were well trained and get necessary experience and knowledge needed to conduct such studies. Within the project duration know-how related to PCL was transferred from Norway to Poland and thanks to this a new expertise was developed in our group, new experiments were carried out and more strength new project proposal were prepared. We do believe that quality of research and prepared papers are much higher thanks to the bilateral cooperation and involvement of Norwegian researchers. They have great experience in interpretation of the results and writing very good papers and hence we are sure that this will help us to increase significance of the results and in the consequence also our project visibility. As an effect of bilateral cooperation we submitted two joined proposals – one in Norway (not funded) and second in Poland (funded) while the next project proposal was recently submitted with Norwegian researchers involved as external experts. What is also important to mention, is that two PhD students of PULS took part in the short term scientific missions funded by the COST Action CLimMani and worked with Norwegian Partner for a few weeks. Besides, two MSc students of PULS took part in a 6-month scientific fellowship in Norway funded by our Partner. One of this student is currently a PhD student at the University of Helsinki, Finland.