Restoration of montane fen meadows by mowing remains possible after 4–35 years of abandonment

Abstract

Billeter R., Peintinger M. and Diemer M. 2007. Restoration of montane fen meadows by mowing remains possible after 4-35 years of abandonment. Bot. Helv. 117: 1 -13.The abandonment of management in Swiss fen meadows has reduced their plant species diversity and the fitness of some typical fen species. We examined whether the resumption of mowing can reverse these effects, and if so, which mechanisms are responsible for community change; we also tested whether restoration success depends on the duration since abandonment. Experimental mowing was applied to 15 montane fen meadows of NE Switzerland that had been abandoned for 4-35 years. After two years of mowing, plant species richness was 11 % higher in mown plots (2 m 2 ) than in fallow plots, approaching levels of neighbouring continuously managed fen meadows. In particular, experimental mowing significantly increased the number of fen indicator species (+15 %) as well as herbs and woody species (seedlings and saplings), while grass, sedge and rush species richness was not affected. Mowing had little effect on aboveground biomass, but strongly reduced litter mass (-50 %) and canopy height (-20 %). Seedling densities of two common species showed opposite responses to mowing: they increased in Carex davalliana and decreased in Succisa pratensis, approaching values of continuously mown fen meadows. Duration since abandonment had no significant effect on any of the variables. Our results demonstrate a rapid recovery of montane fen plant communities irrespective of the duration since abandonment (up to 35 years). We conclude that the restoration of pre-fallow plant community composition is likely to be successful if site conditions (hydrology, nutrient status) remain intact and if common habitat specialists are still present in the vegetation and/or seed bank.

Is regular mowing the most appropriate and cost-effective management maintaining diversity and biomass of target forbs in mountain hay meadows?

“…Our results showed that yearly mowing supports the overall species richness of forbs and target forbs in both meadow types which is in line with other studies (Billeter et al, 2007;Mašková et al, 2009). More forb species proved to be significant character species for mown stands than for abandoned ones in both meadow types.…”

“…It is also stressed that responses of plants to mowing can be highly specific. Some of the studies indicated that some target species were suppressed by regular mowing, which is generally underrated in light of the increase of species richness (Billeter et al, 2007;Diemer et al, 2001).…”

Frequent fire promotes diversity and cover of biological soil crusts in a derived temperate grassland

“…While frequent burning promoted cryptogam richness, cover and abundance, mowing with retained slash led to levels similar to those in less-frequently disturbed plots. By contrast, studies elsewhere have found that mowing promoted bryophyte biomass and cover (Huhta et al 2001;Peintinger and Bergamini 2006;Billeter et al 2007). Similarly, a number of grazing-exclusion studies have demonstrated substantial declines in the cover and diversity of soil bryophytes and lichens following increases in vascular plant cover (Brodo 1961;Looman 1964).…”

Grassland restoration on former croplands in Europe: an assessment of applicability of techniques and costs

“…Bakker 1989); here we focus only on those studies in which some practical aspects for post-restoration are discussed. The most important effect of grazing and mowing is the reduction of aboveground biomass (Diemer et al 2001;Bonanomi et al 2006;Billeter et al 2007). A common phenomenon in grassland restorations is that an accumulation of plant biomass and litter of sown grasses can be observed from the first year onwards.…”