Temperate semi-natural grasslands harbour unique biodiversity, support livestock farming through forage production, and deliver many essential ecosystem services (ESs) to human society; they are highly multifunctional. However, temperate grassland ecosystems are also among the most threatened ecosystems on earth due to land use and climate change. Understanding how biodiversity, climate, and land use intensification impact grassland multifunctionality through complex direct and indirect pathways is critical to better anticipate the future of these fragile ecosystems. 

Here, we evaluate how local plant species richness (SR) modulates the effect of land use intensification and climate on grassland multifunctionality (using six key ESs: biomass productivity and stability, forage quality, carbon storage, pollination, and local plant rarity) in the French Massif Central, the largest grassland in Western-Europe. We sampled 100 grassland fields with contrasted fertilisation rates, and SR over large elevational and latitudinal gradients related to variation in mean annual temperature (MAT), and drought severity (DS), two key climate change drivers that are predicted to increase in the future.

Using a confirmatory path analysis, we found that SR was the main driver of multifunctionality. We also found significant SR × MAT and SR × fertilization interactions suggesting that warm climate and high fertilization rates may alter the biodiversity-ecosystem multifunctionality relationships. Furthermore, increasing temperature and fertilization indirectly influenced multifunctionality by decreasing SR and consequent multifunctionality in warm low-land and highly fertilized grasslands compared to colder montane grasslands or less fertilised ones. DS only impacted some ES individually (e.g. forage quality).

Synthesis and applications: we identified SR as a pivotal factor mediating the effects of land use intensification and climate on multifunctionality through both direct and indirect pathways. Failing to account for changes in SR could thus bias any prediction of – or aggravate – the effects of land use intensification and climate change on ESs delivery in temperate grassland ecosystems. Considering that SR, MAT, and fertilization are major proxies of three main global change drivers (biodiversity loss, climate change, and land use intensification) our study may help to better anticipate the effect of multiple interacting global change drivers on grassland ecosystems.

This dataset of 100 grasslands in Massif Central displays different characteristics of these ecosystems regarding topo-edaphic context, climate, species richness, and management practices. A variable named "multifunctionality" was also calculated, as the average of centered and scaled values of six ecosystem services: biomass productivity, fodder quality, carbon stock in the soil, stability, and local rarity.

This survey across Massif Central took place during three sampling campaigns: 2008 & 2009 for the Prairies AOP project, 2014 & 2015 for the ATOUS project, and 2016-2017 for the AEOLE project. A total number of 143 grasslands were sampled and led to the "Typologie des prairies du Massif Central" or "Typology of the grasslands of Massif Central".

The present dataset shows a subsample of the original database that was completed by climatic data from the SAFRAN database, as well as topographic data from the Copernicus dataset. It was used to study the complex relationships between management, species richness, climate, and multifunctionality in an article currently in revision. All variables of the present dataset, except for the year corresponding to the sampling campaign, were centered and scaled.

To respect the anonymity of the farmers who participated in the survey, the longitude and latitude of the fields are absent from the dataset.