Dew benefits on alpine grasslands are cancelled out by combined heatwave and drought stress
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Dew benefits on alpine grasslands are cancelled out by combined heatwave and drought stress. / Li, Yafei; Eugster, Werner; Riedl, Andreas; Lehmann, Marco M; Aemisegger, Franziska; Buchmann, Nina.
In: FRONT PLANT SCI, Vol. 14, 2023, p. 1136037.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
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T1 - Dew benefits on alpine grasslands are cancelled out by combined heatwave and drought stress
AU - Li, Yafei
AU - Eugster, Werner
AU - Riedl, Andreas
AU - Lehmann, Marco M
AU - Aemisegger, Franziska
AU - Buchmann, Nina
N1 - Copyright © 2023 Li, Eugster, Riedl, Lehmann, Aemisegger and Buchmann.
PY - 2023
Y1 - 2023
N2 - Increasing frequencies of heatwaves combined with simultaneous drought stress in Europe threaten the ecosystem water and carbon budgets of alpine grasslands. Dew as an additional water source can promote ecosystem carbon assimilation. It is known that grassland ecosystems keep high evapotranspiration as long as soil water is available. However, it is rarely being investigated whether dew can mitigate the impact of such extreme climatic events on grassland ecosystem carbon and water exchange. Here we use stable isotopes in meteoric waters and leaf sugars, eddy covariance fluxes for H2O vapor and CO2, in combination with meteorological and plant physiological measurements, to investigate the combined effect of dew and heat-drought stress on plant water status and net ecosystem production (NEP) in an alpine grassland (2000 m elevation) during the June 2019 European heatwave. Before the heatwave, enhanced NEP in the early morning hours can be attributed to leaf wetting by dew. However, dew benefits on NEP were cancelled out by the heatwave, due to the minor contribution of dew in leaf water. Heat-induced reduction in NEP was intensified by the combined effect of drought stress. The recovery of NEP after the peak of the heatwave could be linked to the refilling of plant tissues during nighttime. Among-genera differences of plant water status affected by dew and heat-drought stress can be attributed to differences in their foliar dew water uptake, and their reliance on soil moisture or the impact of the atmospheric evaporative demand. Our results indicate that dew influence on alpine grassland ecosystems varies according to the environmental stress and plant physiology.
AB - Increasing frequencies of heatwaves combined with simultaneous drought stress in Europe threaten the ecosystem water and carbon budgets of alpine grasslands. Dew as an additional water source can promote ecosystem carbon assimilation. It is known that grassland ecosystems keep high evapotranspiration as long as soil water is available. However, it is rarely being investigated whether dew can mitigate the impact of such extreme climatic events on grassland ecosystem carbon and water exchange. Here we use stable isotopes in meteoric waters and leaf sugars, eddy covariance fluxes for H2O vapor and CO2, in combination with meteorological and plant physiological measurements, to investigate the combined effect of dew and heat-drought stress on plant water status and net ecosystem production (NEP) in an alpine grassland (2000 m elevation) during the June 2019 European heatwave. Before the heatwave, enhanced NEP in the early morning hours can be attributed to leaf wetting by dew. However, dew benefits on NEP were cancelled out by the heatwave, due to the minor contribution of dew in leaf water. Heat-induced reduction in NEP was intensified by the combined effect of drought stress. The recovery of NEP after the peak of the heatwave could be linked to the refilling of plant tissues during nighttime. Among-genera differences of plant water status affected by dew and heat-drought stress can be attributed to differences in their foliar dew water uptake, and their reliance on soil moisture or the impact of the atmospheric evaporative demand. Our results indicate that dew influence on alpine grassland ecosystems varies according to the environmental stress and plant physiology.
U2 - 10.3389/fpls.2023.1136037
DO - 10.3389/fpls.2023.1136037
M3 - SCORING: Journal article
C2 - 37229137
VL - 14
SP - 1136037
JO - FRONT PLANT SCI
JF - FRONT PLANT SCI
SN - 1664-462X
ER -