The role of nutrient availability in the drought response of grassland biomass production.

Apart from gradual increases in atmospheric CO2 concentrations and temperature, climate change involves more frequent and intense extreme events, such as storms, heatwaves and droughts. Following a number of real-life cases in the last decades, such as the hot and dry summer of 2003 in Europe, we know that climate extremes can seriously diminish productivity in both natural and agricultural systems and moreover reduce carbon storage in ecosystems, and thus their potential to mitigate climate change. Experiments are improving our understanding of the effects of drought, but too many questions remain unanswered to be able to accurately predict how a particular ecosystem would respond to drought. Soil nutrient availability, which has been demonstrated to modify ecosystem responses to elevated CO2 and temperature, is likely to play a key role in responses to dry spells, among other through its influence on how much plants invest in roots and in their mycorrhizal symbionts. In this project, the influence of nutrient availability, plant carbon allocation and mycorrhizal fungi on drought responses will be investigated by using two ongoing drought experiments in a temperate and an alpine grassland where plant growth is already assessed, but nutrient availability and mycorrhizal fungi are not. These will be determined in the current project to then test their influence on the drought response of grassland productivity.

Keywords:BIOMASS PRODUCTION, GRASSLANDS

Disciplines:Global ecology