Uncovering the critical soil moisture thresholds of plant water stress for European ecosystems

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F86652079%3A_____%2F22%3A00554375" target="_blank" >RIV/86652079:_____/22:00554375 - isvavai.cz</a>

Result on the web

<a href="https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.16050" target="_blank" >https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.16050</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/gcb.16050" target="_blank" >10.1111/gcb.16050</a>

Result language

angličtina

Original language name

Uncovering the critical soil moisture thresholds of plant water stress for European ecosystems

Original language description

Understanding the critical soil moisture (SM) threshold (theta(crit)) of plant water stress and land surface energy partitioning is a basis to evaluate drought impacts and improve models for predicting future ecosystem condition and climate. Quantifying the theta(crit) across biomes and climates is challenging because observations of surface energy fluxes and SM remain sparse. Here, we used the latest database of eddy covariance measurements to estimate theta(crit) across Europe by evaluating evaporative fraction (EF)-SM relationships and investigating the covariance between vapor pressure deficit (VPD) and gross primary production (GPP) during SM dry-down periods. We found that the theta(crit) and soil matric potential threshold in Europe are 16.5% and0.7 MPa, respectively. Surface energy partitioning characteristics varied among different vegetation types, EF in savannas had the highest sensitivities to SM in water-limited stage, and the lowest in forests. The sign of the covariance between daily VPD and GPP consistently changed from positive to negative during dry-down across all sites when EF shifted from relatively high to low values. This sign of the covariance changed after longer period of SM decline in forests than in grasslands and savannas. Estimated theta(crit) from the VPD-GPP covariance method match well with the EF-SM method, showing this covariance method can be used to detect the theta(crit). We further found that soil texture dominates the spatial variability of theta(crit) while shortwave radiation and VPD are the major drivers in determining the spatial pattern of EF sensitivities. Our results highlight for the first time that the sign change of the covariance between daily VPD and GPP can be used as an indicator of how ecosystems transition from energy to SM limitation. We also characterized the corresponding theta(crit) and its drivers across diverse ecosystems in Europe, an essential variable to improve the representation of water stress in land surface models.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10509 - Meteorology and atmospheric sciences

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Global Change Biology

ISSN

1354-1013

e-ISSN

1365-2486

Volume of the periodical

28

Issue of the periodical within the volume

6

Country of publishing house

GB - UNITED KINGDOM

Number of pages

12

Pages from-to

2111-2123

UT code for WoS article

000735992200001

EID of the result in the Scopus database

2-s2.0-85122157145