Drivers of plant phenolic concentration across global drylands

Résumé fourni par la source

Abstract Plant phenolics play a key role in plant defence mechanisms against both biotic and abiotic stressors. However, their responses to environmental variables and grazing pressure across large geographical scales remain poorly understood. Using data from a global survey of 325 plots spanning six continents, we examined how climatic factors, soil properties, leaf nutrients and grazing pressure shape leaf phenolic concentration in 1854 plant species (1280 herbaceous and 574 woody) across global drylands. Our findings reveal that leaf phenolic concentration in herbaceous plants was mainly influenced by grazing pressure and its interactions with leaf nitrogen and iron, which together explained over 50% of observed variation across global drylands. Conversely, phenolic concentration in woody plants was strongly associated with climatic factors, particularly mean annual precipitation (MAP) and mean annual temperature (MAT), which accounted for 80% of the observed variation. While MAP had a positive effect on leaf phenolic concentration in woody plants, grazing pressure buffered this relationship by reducing the influence of MAP. Synthesis. Our study advances the understanding of how biotic and abiotic stressors shape plant defence strategies in global drylands. Our findings shed novel insights about how plant secondary metabolites and their associated functions shift in response to changes in climate and grazing pressure, two key global change drivers with significant implications for ecosystem resilience in drylands worldwide.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.