Increase in soil aggregate stability along a Mediterranean successional gradient in severely eroded gully bed ecosystems: combined effects of soil, root traits and plant community characteristics
Augmentation de la stabilité des agrégats du sol le long d'un gradient méditerranéen de succession végétale dans des écosystèmes de lits de ravines érodées marneuses : effets combinés des caractéristiques du sol, des traits racinaires et des communautés végétales
Erktan, A. ; Cécillon, L. ; Graf, F. ; Roumet, C. ; Legout, C. ; Rey, F.
Type de document
Article de revue scientifique à comité de lecture
Affiliation de l'auteur
IRSTEA GRENOBLE UR EMGR FRA ; IRSTEA GRENOBLE UR EMGR FRA ; WSL SLF DAVOS CHE ; CNRS UMR 5175 CEFE MONTPELLIER FRA ; UNIVERSITE GRENOBLE ALPES UMR 5564 LTHE GRENOBLE FRA ; IRSTEA GRENOBLE UR EMGR FRA
Résumé / Abstract
Background and aims: Our objective was to evaluate changes in soil aggregate stability along a successional gradient in severely eroded Mediterranean gully bed ecosystems (Southern Alps), and to identify the best predictors of soil aggregate stability variations among several soil, root traits and plant community characteristics. Methods: We selected 75 plots (2m2), representing five plant community successional steps in the studied gully beds (15 replicates), showing a wide spectrum of plant growth forms (herbs, shrubs and trees). In each plot, we measured soil aggregate stability, basic soil characteristics, root traits and plant diversity indices. Results: Soil aggregate stability showed wide variations, with more diverse communities and late successional steps being associated with more stable soil aggregates. Soil organic carbon concentration was the main predictor of these variations. In early successional steps characterized by poorly organic soils (SOC< 24 g.kg-1), sand (50 µm < sand < 1 mm) content and percentage of fine roots (for soil with SOC<12 g.kg-1 only) favored soil aggregate stability while silt content decreased it. Conclusion: Plant succession in severely eroded Mediterranean gully bed ecosystems by plant communities is accompanied by a stabilization of soil aggregates, which is mainly driven by SOC accumulation and, for early successional steps showing poorly organic soils, by soil granulometry and root traits as co-drivers.
Plant and Soil, vol. 398, num. 1-2, p. 121 - 137