Low- cost management interventions and their impact on multilevel trade- offs in agricultural grasslands

1. Cost- effective strategies to increase biodiversity are a fundamental requirement to reconcile conservation and food production in agricultural landscapes. Key for the implementation of such strategies is an accurate quantification of both their benefits and potential associated trade- offs.

2. We therefore assessed, in a commercially managed grassland, biodiversity responses to two low- cost management interventions and their mediating effects on ecosystem services.

3. In a 6- year experiment, we showed that a one- time seed bank activation treatment had strong initial impacts on biodiversity, increasing plant richness in year 1 by 61%. Long- term effects, which were also driven by the second management intervention, the propagation of the keystone species yellow rattle, were weaker but nonetheless substantial. These positive biodiversity responses improved ecosystem multifunctionality through additive positive effects of richness, evenness and phylogenetic distinctiveness on nectar production and structural habitat complexity.

4. In contrast, hay biomass production was negatively affected by both management interventions, resulting in a multilevel trade- off between biomass production competing with biodiversity conservation and the provisioning of other ecosystem services.

5. Synthesis and applications. In this study, we demonstrate that the maximisation of either biodiversity or biomass production requires largely different land management practices. The evaluation of this trade- off, however, is strongly dependent on its social, economic and ecological context and requires clearly defined land management priorities for both food production and biodiversity conservation.