Poster, Annual Meeting Ecological Society of America (ESA), Austin, USA: 2011-08-07 - 2011-08-11
Greater intra-annual precipitation variability is predicted for many regions on earth, leading to longer dry periods and more intense rainfall events. Recent studies suggest that changed precipitation variability is altering grassland productivity but it remains unclear how forage quality is affected. Here, we present first results from the field experiment EVENT II in which Central European grassland is subjected to increased spring and summer rainfall variability (low, mid and extreme rainfall variability without any change to the annual rainfall amount). Additionally, we examined the application of fertilizer and the delay of mowing as buffer methods against loss of forage quantity and quality. We assessed biomass production and forage quality parameters such as crude protein, crude ash, crude fat and fibre, sugar content as well as neutral detergent fibre (NDF). Biomass production, NDF, crude fibre and sugar content was decreasing with increasing precipitation variability. Fertilizer could not buffer these effects. When extreme events occurred later in the year, crude protein, sugar and biomass were stronger decreased and crude fibre and fat increased. With delayed mowing the reduction of crude protein by increased variability was buffered. These results may contribute to the discussion how to mitigate the effects of climate change on agricultural landuse.