Effects of mixing tree species and water availability on soil organic carbon stocks are depth dependent in a temperate podzol
MEREDIEU, Céline
Unité expérimentale Forêt Pierroton [UEFP]
Biodiversité, Gènes & Communautés [BioGeCo]
< Réduire
Unité expérimentale Forêt Pierroton [UEFP]
Biodiversité, Gènes & Communautés [BioGeCo]
Langue
en
Article de revue
Ce document a été publié dans
European Journal of Soil Science. 2021-06, vol. 73, n° 1
Wiley
Résumé en anglais
Mixing tree species is a forest management strategy put forward to increase and stabilize primary productivity. Yet, little is known about soil organic carbon (SOC) storage in mixed species forests, particularly under water ...Lire la suite >
Mixing tree species is a forest management strategy put forward to increase and stabilize primary productivity. Yet, little is known about soil organic carbon (SOC) storage in mixed species forests, particularly under water shortage. In this study, we used a tree diversity experiment in southwestern France to assess the interactive effects of water availability (via irrigation) and mixing tree species (monocultures of pine ( Pinus pinaster ) and birch ( Betula pendula ) versus mixed plots of pine‐birch and pine‐birch‐oak ( Quercus robur )) on SOC stocks in the forest floor and across five mineral soil layers (0–5, 5–15, 15–30, 30–60 and 60–90 cm deep). We found that SOC stocks were negatively affected by irrigation in the forest floor due to an increase in decomposition rates. However, SOC stocks were positively influenced by both the mixing of tree species and irrigation in the mineral soil, particularly at the 15–30‐cm soil depth. This is because root niche partitioning in mixed plots and an increase in tree biomass in irrigated plots may have resulted in greater organic matter inputs through rhizodeposition and the incorporation of microbially‐derived compounds. These preliminary results indicate that SOC dynamics and its response to biotic and abiotic factors are strongly dependent on soil depth. Our data further highlight that the positive effect of mixing trees on SOC stocks was higher in irrigated plots, thereby contradicting the idea that tree mixture effects are expected to be greater when environmental conditions are harsher. We conclude that mixing tree species can increase SOC stocks in the short term in temperate forests, even if the exact mechanisms remain to be identified. Highlights Effects of mixing trees and increasing water availability on SOC are depth dependent. Increase in SOC stocks occurred mainly at the mid‐soil depth (15–30 cm). Effects of tree mixture on SOC were greater when soil water availability was high.< Réduire
Mots clés en anglais
aboveground-belowground linkages
drought
forest carbon sequestration
plant-soil interactions
tree species identity
Project ANR
Diversité et Productivité des forêTs impactées par le Changement Climatique - ANR-16-CE32-0003
CARbone, Traits fonctionnels associés, et leur OptimisatioN - ANR-19-CE32-0006
CARbone, Traits fonctionnels associés, et leur OptimisatioN - ANR-19-CE32-0006
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