Forage nutritive value shows synergies with plant diversity in a wide range of semi-natural grassland habitats

Cian Blaix (1) , Olivier Chabrerie (2) , Didier Alard (3) , Manuella Catterou (2) , Sylvain Diquelou (4) , Thierry Dutoit (5) , Jérôme Lacoux (2) , Grégory Loucougaray (6) , Alice Michelot-Antalik (7) , Marine Pacé (1) , Antoine Tardif (2) , Servane Lemauviel-Lavenant (4) , Anne Bonis (1)

1 GEOLAB - Laboratoire de Géographie Physique et Environnementale
2 EDYSAN - Ecologie et Dynamique des Systèmes Anthropisés - UMR CNRS 7058
3 BioGeCo - Biodiversité, Gènes & Communautés
4 EVA - Ecophysiologie Végétale, Agronomie et Nutritions NCS
5 IMBE - Institut méditerranéen de biodiversité et d'écologie marine et continentale
6 UR LESSEM - Laboratoire des EcoSystèmes et des Sociétés en Montagne
7 LAE - Laboratoire Agronomie et Environnement

This paper aims in assessing the relationship between grassland plant diversity and agronomic value, which represents a major challenge to reconcile nature conservation and agricultural use of semi-natural grassland habitats. The effects of plant diversity and functional traits were studied on forage nutritive value and early standing biomass in a wide set of semi-natural temperate grassland habitats. Plant communities were described by their species and functional diversity, community-weighted means (CWM) of plant functional traits, and the relative cover of main plant functional types (graminoids, forbs, and legumes). Species richness was found to be negatively associated with early standing biomass and average mineral content. Community evenness, for both species and plant functional types, was positively correlated with digestibility, crude protein content, and average mineral content but negatively with early standing biomass. Early standing biomass was found to increase with increasing graminoid cover and to decrease with increasing forb cover. Forage nutritive value improved with higher legume cover, higher specific leaf area CWM and lower leaf dry matter content CWM, while these functional community characteristics were not found to impact early standing biomass. Our results highlight that a better forage nutritive value can be obtained with a higher plant species evenness in permanent grassland habitats. Furthermore, in grasslands with an even distribution of plant functional types, forage nutritive value may be improved with no loss in early standing biomass.

Mots clés: Grassland conservation; Species diversity; Forage quality; Functional diversity; Evenness

Domaines: Sciences de l'environnement; Sciences du Vivant [q-bio]

Cian Blaix, Olivier Chabrerie, Didier Alard, Manuella Catterou, Sylvain Diquelou, et al.. Forage nutritive value shows synergies with plant diversity in a wide range of semi-natural grassland habitats. Agriculture, Ecosystems & Environment, 2023, 347, pp.108369. ⟨10.1016/j.agee.2023.108369⟩. ⟨hal-03974283⟩