Plant functional groups, conservation values and ecosystem services
All the plots disturbed in 2019 were disturbed again in 2020, while all plots intact in 2019 remained intact also in 2020. The effect of disturbance was significant on all the studied parameters (Table 1). Total vegetation cover, cryptogam cover and the cover of perennial graminoids were smaller in the disturbed plots than in the intact grasslands, while perennial forbs, short-lived forbs and short-lived graminoids were more abundant in the disturbed plots (Figure 3A-F). The disturbed plots were characterised by larger Shannon diversity (Figure 4A) and smaller naturalness score (Figure 4B) than the intact grasslands. Forage quality (Figure 4C) decreased and specific leaf area (Figure 4D) increased as a result of the disturbance. Plant species tended to have longer flowering period in the disturbed plots (Figure 4E). The cover of insect-pollinated plants was larger in the disturbed plots compared to the intact grasslands (Figure 4F).
We identified significant interaction terms (Table 1) which shows that the effect of disturbance on the vegetation characteristics were mediated by year (in case of 7 variables), season (in case of 7 variables), or the interaction of year and season (in case of 6 variables). Vegetation changes were consistent in the intact grasslands across the study years and seasons.