DOI: 10.5061/dryad.4j0zpc8hz
title: Chronic warming and dry soils limit carbon uptake and growth despite a longer growing season in beech and oak

description: Progressively warmer and drier conditions impact tree phenology and carbon
 cycling with large consequences for forest carbon balance. However, it
 remains unclear how separate impacts of warming and drier soils differ
 from their cumulative ones and how species interactions modulate tree
 responses. Using mesocosms, we assessed the multi-year impact of
 continuous air warming and lower soil moisture acting alone or combined on
 phenology, leaf-level photosynthesis, non-structural carbohydrate
 concentrations, and aboveground growth of young European beech and Downy
 oak trees. We further tested how species interactions (monocultures vs.
 mixtures) modulated these effects. Warming prolonged the growing season of
 both species but reduced growth for oak. In contrast, lower moisture did
 not impact phenology but reduced trees' assimilation and growth for
 both species. Combined impacts of warming and drier soils did not differ
 from single ones. Performances of both species in the mixtures were
 enhanced compared to the monocultures under extreme conditions. Our work
 revealed that higher temperature and lower soil moisture have contrasting
 impacts on phenology vs. leaf-level assimilation and growth, with the
 former being driven by temperature and the latter by moisture.
 Furthermore, we show a compensation of the negative impacts of extreme
 events by tree species interactions.
description: Phenology (i.e., bud swelling, duration of bud development, onset
 and duration of senescence, growing season length), leaf-level carbon
 relations (i.e., starch and sugar concentrations, light-saturated
 assimilation, Asat) traits and growth traits (height, diameter, and
 aboveground biomass (AGB) increment) were measured on 96 seedlings of
 European beech and downy oak trees grown in monocultures and mixtures.
 Phenology, leaf-level carbon relations and growth traits were measured on
 the selected trees for three years (i.e., from 2019 to 2021). Phenology
 and growth traits were measured annually, and leaf-level carbon relations
 were measured three times a year during the growing season (i.e., early,
 middle, and late growing season). During the first campaign of measurement
 (i.e., early growing season 2019), trees did not exercise any climatic
 treatment, and afterward, a fully crossed combination of two air
 temperature (i.e., ambient air temperature and air warming at +5°C) and
 soil moisture regimes (i.e., soil moisture maintained at field capacity
 and soil moisture reduction of 50%) started. Light-saturated assimilation
 measurements were carried out between 9 am and 4 pm when the trees were
 the most active, excluding periods of midday stomatal closure if they
 occurred (mostly between 12am and 2pm in the middle of the growing
 season).
description: Excel files or R studio can open the datafiles included with the
 submission
description: # Chronic warming and dry soils limit carbon uptake and growth despite a
 longer growing season in beech and oak
 [https://doi.org/10.5061/dryad.4j0zpc8hz](https://doi.org/10.5061/dryad.4j0zpc8hz) Raw data belonging to the following manuscript published in *Plant Physiology*: Didion-Gency, M., Vitasse, Y., Buchmann, N., Gessler, A., Gisler, J., Schaub, M., Grossiord, C. (2023) Chronic warming and low soil moisture conditions limit carbon uptake and growth despite a longer growing season in beech and oak This README belongs to the file call: Dryad\_Data\_PlantPhy\_MargauxDidionGency.xlsx If you need more information, contact is below: Margaux DIDION-GENCY [margaux.didion-gency@epfl.ch](mailto:margaux.didion-gency@epfl.ch) 0033(0)674272796 Plant Ecology Research Laboratory PERL, School of Architecture, Civil and Environmental Engineering, EPFL, CH-1015 Lausanne, Switzerland