Evidence map›Paper›PMID 39660997›Full record

ArticleTree physiology2025

Field integration of shoot gas-exchange and leaf chlorophyll fluorescence measurements to study the long-term regulation of photosynthesis in situ.

Jaakko Oivukkamäki, Juho Aalto, Erhard E Pfündel, Manqing Tian, Chao Zhang, Steffen Grebe, Yann Salmon, Teemu Hölttä, Albert Porcar-Castell

Abstract read
In one paragraph

Article in Tree physiology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed.

  1. Article
  2. Article
  3. Estimating COBMC plant biology · 2025
    Article
  4. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Jaakko OivukkamäkiOptics of Photosynthesis Laboratory, Institute for Atmospheric and Earth System Research (INAR)/Forest Sciences, Viikki Plant Science Center, Latokartanonkaari 7-9, 00014 University of Helsinki, Helsinki, Finland.
Juho AaltoHyytiälä Forestry Field Station, Hyytiäläntie 124, 00014 University of Helsinki, Korkeakoski, Finland.
Erhard E PfündelHeinz Walz GmbH, Eichenring 6, D-91090 Effeltrich, Germany.
Manqing TianInstitute for Atmospheric and Earth System Research (INAR)/Forest Sciences, Latokartanonkaari 7-9, 00014 University of Helsinki, Helsinki, Finland.
Chao ZhangOptics of Photosynthesis Laboratory, Institute for Atmospheric and Earth System Research (INAR)/Forest Sciences, Viikki Plant Science Center, Latokartanonkaari 7-9, 00014 University of Helsinki, Helsinki, Finland.
Steffen GrebeOptics of Photosynthesis Laboratory, Institute for Atmospheric and Earth System Research (INAR)/Forest Sciences, Viikki Plant Science Center, Latokartanonkaari 7-9, 00014 University of Helsinki, Helsinki, Finland.
Yann SalmonInstitute for Atmospheric and Earth System Research (INAR)/Forest Sciences, Latokartanonkaari 7-9, 00014 University of Helsinki, Helsinki, Finland.
Teemu HölttäInstitute for Atmospheric and Earth System Research (INAR)/Forest Sciences, Latokartanonkaari 7-9, 00014 University of Helsinki, Helsinki, Finland.
Albert Porcar-CastellOptics of Photosynthesis Laboratory, Institute for Atmospheric and Earth System Research (INAR)/Forest Sciences, Viikki Plant Science Center, Latokartanonkaari 7-9, 00014 University of Helsinki, Helsinki, Finland.

Funding

Faculty of Agriculture and forestry, University of HelsinkiThe Atmosphere and Climate Competence Center (ACCC))
6 · The paper itself

Abstract

Understanding the diurnal and seasonal regulation of photosynthesis is an essential step to quantify and model the impact of the environment on plant function. Although the dynamics of photosynthesis have been widely investigated in terms of CO2 exchange measurements, a more comprehensive view can be obtained when combining gas-exchange and chlorophyll fluorescence (ChlF). Until now, integrated measurements of gas-exchange and ChlF have been restricted to short-term analysis using portable infrared gas analyzer systems that include a fluorometer module. In this communication we provide a first-time demonstration of long-term, in situ and combined measurements of photosynthetic gas-exchange and ChlF. We do so by integrating a new miniature pulse amplitude modulated-fluorometer into an existing system of automated chambers to track photosynthetic gas-exchange of leaves and shoots in situ. The setup is used to track the dynamics of the light and carbon reactions of photosynthesis at a 20-min resolution in leaves of silver birch (Betula pendula Roth) during summertime. The potential of the method is illustrated using the ratio between electron transport and net assimilation (ETR/ANET), which reflects the internal electron use efficiency of photosynthesis. The setup successfully captured the diurnal patterns in the ETR/ANET during summertime, including a large increase in noon ETR/ANET in response to a period of high temperatures and relatively low soil moisture, pointing to a drastic decrease in electron-use efficiency. The observations emphasize the value of combined and long-term in situ measurements of ChlF and gas-exchange, opening new opportunities to investigate, model and quantify the regulation of photosynthesis in situ and the connection between ChlF and photosynthetic gas-exchange. The next steps, potential and limitations of the approach are discussed.

Indexed as

BetulaChlorophyllPhotosynthesisPlant LeavesPlant ShootsCarbon DioxideCircadian RhythmElectron TransportFluorescenceSeasonsCarbon DioxideChlorophyllalternative energy sinksBetula pendulaelectron transport ratefield measurementsMICRO-PAMpulse-amplitude modulation (PAM)silver birch

Identifiers

PMID39660997
PMCPMC11775469

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.