Differentiation and preservation status of wet meadows of the Calthion palustris alliance in areas covered by the agri-environmental scheme

The research subject is the differentiation of plant communities and the preservation status of wet meadows of the Calthion palustris alliance at sites included in subsidy packages 4 and 5 of the agri-environmental scheme. The habitat was studied on 697 agri-environmental plots located in different areas of Poland. The obtained results show high differentiation of the plant communities, which could be considered as representative of the Calthion palustris alliance meadows in Poland. Disturbances in the habitat conditions were observed on most of the plots and they included: disappearance of characteristic species of the Calthion palustris alliance, encroachment of native, expansive species as well as desiccation of the habitat and the associated eutrophication, caused mostly by unidirectional land drainage systems. The study also attempted to determine the conservation prospects of the habitat considering measures implemented under the agri-environmental scheme

Understanding the long term ecosystem stability of a fen mire by analyzing subsurface geology, eco-hydrology and nutrient stoichiometry - Case study of the Rospuda valley (NE Poland)

We explored the background of differences in long-term stability between two parts in an undisturbed mire system (Rospuda fen, NE Poland). We re-constructed the Holocene history of the mire and compared it with current vegetation, water level dynamics, water chemistry and nutrient availability in two basins: A, where the mire terrestrialised a deep gyttja-filled lake, and B, where peatland developed directly on fluvial sands. The current vegetation of sedge-moss fens was described in 10 relevés from each basin, groundwater was sampled from piezometers and analysed for major ions, while its relative water level was recorded during three years. N and P content was measured in above ground vascular plant samples collected within the relevés. Fens in basin A were stable in the past, whereas fens in basin B switched between open and wooded or reed-dominated phases. In basin B, where trees are more abundant, we found higher water fluctuations, occurrence of river floods and a higher N:P ratio than in basin A. Our interpretation follows that the subsurface geology of fen basin may govern mire stability by determining its hydrological-buffering capacity, which may affect N:P ratios. Our results suggest that P-limited fens are more vulnerable for changes in water level