The Grass Garden in the Giant Mts. (Czech Republic): Residual effect of long-term fertilization after 62 years

The aim of the study was to investigate how plant species’ composition, soil parameters and nutrient concentrations in plant biomass differ between fertilized and control plots 62 years after the last fertilizer application on a sub-alpine grassland. A piece of land called the Grass Garden (GG), fertilized with wood ash and manure for at least 200 years, was rediscovered in the Giant Mts. (Krkonoše, Karkonosze) in 2006. The last fertilization was applied in 1944. The central part of GG (treatment A), the edge of GG (treatment B) and never-fertilized control plots outside of GG (treatment C) were distinguished. Sixty-two years after the last fertilization Nardus stricta was dominant in treatment C and Deschampsia cespitosa and Avenella flexuosa in treatments A and B. The predominance of these grasses was first described in 1786 and repeatedly during the 19th and 20th centuries and indicated the long-term stability of plant species’ composition in the sub-alpine grassland. In the case of GG, long-term fertilization has had a long-term “stable after-effect” upon differences in plant species’ composition. Ca concentration in the soil was more than two times higher in treatments A and B than in the control, indicating that it was very difficult to deplete applied Ca even on extreme podzol soils and under the climatic conditions of the sub-alpine vegetation belt. In above-ground plant biomass, Mg and P concentrations and N:P ratio were still significantly affected by treatment.