20.5.21

Grazing under climate change: quantifying the relationship between rainfall, grazing pressure and plant primary production

The GRAZE project has concluded a field experiment combining a factorial combination of:

-        Three rainfall levels: +30%, -30% and control. The -30% reduction coincides with forecasted levels of rainfall decrease under current climate-change scenarios.

-        Six levels of simulated herbivory, using clipping frequencies ranging from biweekly applications (highest level of simulated herbivory) to a last harvest closely after seed production (no-grazing control) .

The experiment was deployed in the mesic grasslands (‘vera’) of the Doñana Biological Reserve. Following an interrupted attempt during the spring of 2020, it was re-started in October 2020 and reached the first final harvest, coinciding with the end of the growth season, on 12-13 May 2021. We plan to extend the experiment three years more, evaluating the long-term, accumulated impact of the different experimental treatments.

  Setup and general view of GRAZE’s ‘rainfall x grazing pressure’ experiment. 

 




Images from the final harvest of the experiment’s first growth season.