Title: Response of Ecosystem Productivity to High Vapor Pressure Deficit and Low Soil Moisture: Lessons Learned From the Global Eddy-Covariance Observations

Abstract

Although there is mounting concern about how high vapor pressure deficit (VPD) and low soil moisture (SM) affect ecosystem productivity, their relative importance is still under debate. Here, we comprehensively quantified the relative impacts of these two factors on ecosystem gross primary production (GPP) using observations from a global network of eddy-covariance towers and two approaches (sensitivity analysis and linear regression model). Both approaches agree that a higher percentage of sites experience GPP reduction from high VPD than from low SM over the growing season. However, the constraint of high VPD and low SM on GPP reduction is tightly linked with climates and plant functional types. Humid and mesic ecosystems including forests and grasslands are dominated by VPD, while the semi-arid and arid ecosystems including shrublands and savannas are dominated by SM. The varying dominant role of these two factors on GPP is closely related to plant stomatal behavior, as predicted by a stomatal conductance model. Additionally, we highlight the non-linear impact of SM on GPP during droughts and the possible underestimation of the SM effects for deep-rooted plants when only using surface-layer SM. Our results shed light on a better understanding of the impacts of VPD and SM onmore » vegetation productivity, with important implications for modeling the response and feedback of ecosystem dynamics to current and future climates.« less

Authors:

Xu, Shiqin  ^[1];

• Search DOE PAGES for author "Xu, Shiqin"
• Search DOE PAGES for ORCID "0000-0002-4899-0598"

Gentine, Pierre  ^[2];

• Search DOE PAGES for author "Gentine, Pierre"
• Search DOE PAGES for ORCID "0000-0002-0845-8345"

Li, Lingcheng  ^[3];

• Search DOE PAGES for author "Li, Lingcheng"
• Search DOE PAGES for ORCID "0000-0002-6834-5844"

Wang, Lixin  ^[4];

• Search DOE PAGES for author "Wang, Lixin"
• Search DOE PAGES for ORCID "0000-0003-0968-1247"

Yu, Zhongbo  ^[5];

• Search DOE PAGES for author "Yu, Zhongbo"
• Search DOE PAGES for ORCID "0000-0002-3471-8577"

Dong, Ningpeng  ^[6];

• Search DOE PAGES for author "Dong, Ningpeng"
• Search DOE PAGES for ORCID "0000-0002-5226-6180"

Ju, Qin ^[5]; Zhang, Yuliang ^[7]

---

+ Show Author Affiliations

1. King Abdullah University of Science and Technology, Thuwal (Saudi Arabia); Northwest Normal University (NWNU) Lanzhou (China); Key Laboratory of Resource Environment and Sustainable Development of Oasis, Lanzhou (China)
2. Columbia University, New York, NY (United States)
3. Pacific Northwest National Laboratory (PNNL), Seattle, WA (United States)
4. Indiana University‐Purdue University, Indianapolis, IN (United States)
5. Hohai University, Nanjing (China)
6. Institute of Water Resources and Hydropower Research, Beijing (China)
7. Hefei University of Technology (China)

Publication Date:

Fri Aug 25 00:00:00 EDT 2023

Research Org.:

Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

Sponsoring Org.:

USDOE; National Natural Science Foundation of China (NSFC); Northwest Normal University (NWNU) Foundation; Belt and Road Special Foundation

OSTI Identifier:

2212435

Report Number(s):

PNNL-SA-178332
Journal ID: ISSN 2328-4277

Grant/Contract Number:  

AC05-76RL01830; 42101045; NWNU-LKQN2021-35; 2020490711

Resource Type:

Accepted Manuscript

Journal Name:

Earth's Future

Additional Journal Information:

Journal Volume: 11; Journal Issue: 8; Journal ID: ISSN 2328-4277

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES