ASSESSMENT OF THE DEGREE OF SODDING AND FLORISTIC COMPOSITION OF THE SLOPES OF THE RACIBÓRZ DOLNY DRY RESERVOIR

Kamila Musiał; Beata Grygierzec

doi:10.37660/aspagr.2021.20.4.1

Kamila Musiał National Research Institute of Animal Production, Department of Production Systems and Environment, Krakowska 1, 32-083 Balice, Poland http://orcid.org/0000-0002-6713-341X
Beata Grygierzec University of Agriculture in Krakow, Department of Agroecology and Plant Production, Mickiewicza 21, 31-120 Kraków, Poland http://orcid.org/0000-0003-2403-8735

DOI: http://dx.doi.org/10.37660/aspagr.2021.20.4.1

Abstract

Background. The Racibórz Dolny reservoir is a polder located in the Odra Valley in the Silesian Province. It covers area of 26.3 km² and its capacity is estimated to reach 185 million m³. It was under construction between 2013 and 2020, when it became operational. It currently operates as part of the passive and active flood protection system. An important part of flood control reservoirs is the slope, the reinforcement of which can be of a biological nature. It then takes the form of turf, built mainly by plant species from the Poaceae and Fabaceae families.
Material and methods. Projective cover was calculated for individual species that occur in the turf on the reservoir slopes. This made it possible to determine the percentage composition, and then to quantify vascular plant species. The COBORU methodology was applied to assess the scale of sodding, which includes a 9-grade rating scale.
Results. On the slopes, sodding was found which was created by sowing grass mixtures, mainly Festuca rubra L. and Lolium perenne L. They demonstrated ground cover from about 25%–75% (quantity 3–4) to 75.1%–100% (quantity 5). They were accompanied by Trifolium repens L., Vicia hirsuta L.S.F. Gray, and Festuca arundinacea (Schreb.). Many other vascular plant species with low cover were also found. Density of turf on slopes was diversified and reached from 45% in the lower part of the slope in part ZC, to 100% in the upper parts of the slope in sections ZC, ZP, and ZL.
Conclusion. In less than two years after the slopes of the Racibórz Dolny dry reservoir were managed by sowing grass mixtures, it was found that their sodding was diversified. The lower parts of the slopes on both the dehydration and vent side were more poorly sodded. It appears that grass species more predisposed to sowing in such artificial communities could be Poa pratensis L., Agrostis capillaris L., and Festuca ovina L. This may serve to achieve proper sodding, which, as a result, is expected to strengthen and protect the slopes against erosion.