Effects of grassland management on the global carbon cycle.

Abstract

In global dynamic vegetation models such as LPJmL, usually management on grassland is represented by rather simple assumptions. These aim e.g. at the inclusion of a harvesting mode that reduces leaf biomass and ensures productivity dependent biomass removal. This management is mostly not ideal, i.e. maximizing harvest (as implemented in LPJmL default) without ensuring livestock feed for the vegetation period or avoiding soil carbon loss. Apart from assessments of the effects of homogeneously distributed managed options, investigations of currently applied management can help to find out which grass harvesting options could be favoured for sustainable intensification of grassland.Using a global dataset of grassland management (Chang et al., 2016, Biogeosciences) in combination with the dataset of the livestock density distribution (Herrero et al., 2013, PNAS), current carbon fluxes and pools on grassland are investigated using LPJmL with grassland management options (Rolinski et al., submitted to GMD). Here, feedbacks of harvesting aboveground grass biomass on productivity (NPP) and soil carbon development are quantified especially for intensively used pasture in Europe.