Langfristige Auswirkungen ehemaliger Bewirtschaftungsvarianten auf die Diversität von Blütenpflanzen, Moosen und Flechten eines Kalkmagerrasens

Abstract

Jeschke M., Kiehl K., Pfadenhauer J. and Gigon A. 2008. Long-term effects of former management on the diversity of vascular plants, mosses and lichens in a calcareous grassland. Bot. Helv. 118: 95 -109.Long-term effects of grassland management on the species richness of vascular plants, mosses and lichens were studied in a calcareous grassland near Schaffhausen (Switzerland). Experimental plots were treated for 22 years (1977 -1999) with different mowing regimes, annual burning in late winter, or abandonment. From 2000 onwards, all plots were mown annually in autumn. Five years later (2004), we studied the aftereffects of the previous treatments by recording the cover of vascular plants, mosses and lichens in nested plots with sizes from 0.01 m 2 to 16 m 2 . Vascular plant species richness as well as the number of species characteristic for calcareous grasslands were significantly lower in formerly abandoned or burnt plots than in regularly mown plots, with larger differences on small subplots. There was no significant effect of the previous mowing time (July vs. October) or mowing frequency (annual or every two years) on vascular plants. Mosses and lichens had been eliminated by annual burning between 1977 and 1999, and only few moss species re-colonized the formerly burnt plots until 2004. The species richness of mosses did not differ between formerly abandoned and mown plots, but there were more mesophytic and fewer xerophytic species in the formerly abandoned plots. Mesophytic mosses were also more abundant in plots that used to be mown every second year than in those mown annually. Our data indicate that even after five years of similar management, i.e. annual mowing in autumn, the previous Bot. Helv. 118 (2008): 95 -109 0253-1453/08/020095-15 DOI 10.1007/s00035-008-0853-z Birkhäuser Verlag, Basel, 2008 Botanica Helvetica long-term management had strong after-effects on species richness and species composition of calcareous grasslands.

Mycorrhizal infection indicates the suitability of different management treatments for nature conservation in calcareous grassland

“…This differentiation may be related to plant nutrient availability (Alard et al 2005;Römermann et al 2005;Schmidt 2006a), as mowing is assumed to lead to a loss of nutrients, whereas mulching every second year and succession are leading to an accumulation of litter and probably also of nutrients Moog et al 2002). Burning leads to advanced nutrient availability (principally phosphate) without litter accumulation (Schreiber et al 2009b), but it is not well suited to conserve the initial vegetation composition Jeschke et al 2008). However, we did not find any relationship between management intensity and soil nitrogen content, whereas soil content of phosphate generally increased with management intensity (with the exception of the succession treatment).…”