Abstract
Modeling terrestrial gross primary productivity (GPP) is central to predicting the global carbon cycle. Much interest has been focused on the environmentally induced dynamics of photosystem energy partitioning and how improvements in the description of such dynamics assist the prediction of light reactions of photosynthesis and therefore GPP. The maximum quantum yield of photosystem II (8PSIImax) is a key parameter of the light reactions that influence the electron transport rate needed for supporting the biochemical reactions of photosynthesis. 8PSIImax is generally treated as a constant in biochemical photosynthetic models even though a constant 8PSIImax is expected only for non-stressed plants. We synthesized reported 8PSIImax values from pulse-amplitude-modulated fluorometry measurements in response to variable temperatures across the globe. We found that 8PSIImax is strongly affected by prevailing temperature regimes with declined values in both hot and cold conditions. To understand the spatiotemporal variability in 8PSIImax, we analyzed the temperature effect on 8PSIImax across plant functional type (PFT) and habitat climatology. The analysis showed that temperature’s impact on 8PSIImax is shaped more by climate than by PFT for plants with broad latitudinal distributions or in regions with extreme temperature variability. There is a trade-off between the temperature range within which 8PSIImax remains maximal and the overall rate of decline of 8PSIImax outside the temperature range such that species cannot be simultaneously tolerant and resilient to extreme temperatures. Our study points to a quantitative approach for improving electron transport and photosynthetic productivity modeling under changing climates at regional and global scales.
| Original language | English |
|---|---|
| Pages (from-to) | 2731-2758 |
| Number of pages | 28 |
| Journal | Biogeosciences |
| Volume | 21 |
| Issue number | 11 |
| DOIs | |
| State | Published - Jun 11 2024 |
Funding
Financial support. The research has been supported by the University of Arizona Faculty Start-up funding and the DOE, Office of Science, Biological and Environmental Research (BER) program. This article has been co-authored by UT-Battelle, LLC, under contract no. DE-AC05-00OR22725 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this article, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan , last access: 6 October 2023). We acknowledge the support from the University of Arizona and the U.S. Department of Energy (DOE), Oak Ridge National Lab. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the DOE under contract DE-AC05-00OR22725. We are especially grateful to the two reviewers whose insightful comments and suggestions help improve this article.