Strong links between plant traits and microbial activities but different abiotic drivers in mountain grasslands
Résumé
Aim Plant–soil interactions can be major driving forces of community responses to environmental changes in terrestrial ecosystems. These interactions can leave signals in aboveground plant functional traits and belowground microbial activities and these signals can manifest in observed covariations. However, we know little about how these plant–soil linkages vary in response to environmental conditions at biogeographic scales for which experiments are impossible. Here, we investigate patterns of direct and indirect linkages between plant functional traits, soil microbial activities and environmental conditions in mountain grasslands along elevational gradients. Location The French Alps. Taxon Vascular plants and soil microbiota. Methods We analysed observational grassland data sampled along 14 elevational gradients across the entire French Alps (between 1500 and 2800 m of elevation). Using Graphical Lasso, we inferred a partial correlation network to tease apart direct and indirect plant–soil linkages without defining the direction of interactions a priori. Results We found tight spatial associations of plant traits with microbial activities, climate driving the former and soil properties the latter. In these plant–soil linkages, the dominance of specific plant traits was more important than their diversity. We then showed that in sites with conservative plant traits and reduced organic matter quality, soil microbes invested strongly in nutrient acquisition. Main conclusions By investigating plant–soil linkages along elevational gradients in the French Alps, we showed that plant functional traits and belowground microbial activity are tightly linked and how they depend on environmental conditions. Overall, we demonstrated how soil functioning can be integrated in studies of ecosystem shifts under environmental change at large spatial scales.
Auteurs, date et publication :
Auteurs Sarah-Sophie Weil , Camille Martinez-Almoyna , Gabin Piton , Julien Renaud , Louise Boulangeat , Arnaud Foulquier , Amélie Saillard , Philippe Choler , Jérôme Poulenard , Orchamp Consortium , Tamara Münkemüller , Wilfried Thuiller
Publication : Journal of Biogeography
Date : 2025
Volume : 48
Issue : 11
Pages : 2755-2770