Journal article
Comparative analysis of diurnal thermal stress responses and lag effects in Acer campestre using chlorophyll fluorescence during UK summers 2022–2023
- Abstract:
- Urban trees face increasing extreme heat, yet the timing of their short-term physiological responses remains unclear. This study investigated thermal stress dynamics in Acer campestre during two contrasting UK summers (2022 and 2023) and examined how sampling frequency affects the detection of temporal lag effects. Chlorophyll fluorescence parameters (NPQ and ETRmax) were measured daily during the 2022 high heat days and weekly under the milder conditions of 2023. Generalised linear mixed models and cross-correlation analyses explored the relationships between leaf temperature and photosynthetic performance. In 2022, NPQ showed increased morning thermal sensitivity under extreme heat, but detrended analyses did not reveal strong multi-day lag effects. ETRmax responded in synchrony with temperature, showing no detectable time lag. In 2023, apparent multi-day correlations matched exactly with the weekly sampling interval and were diminished or nullified by detrending, suggesting sampling artefacts rather than physiological memory. Across both years, morning measurements consistently indicated the greatest thermal sensitivity. These findings reveal that Acer campestre exhibits threshold-dependent stress responses and highlight the importance of high-frequency sampling for accurately capturing short-term physiological dynamics. Sparse sampling can produce misleading lag patterns, emphasising the need to match measurement frequency with the biological response timescales in urban tree monitoring.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
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(Preview, Version of record, pdf, 2.4MB, Terms of use)
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- Publisher copy:
- 10.1007/s41748-025-01021-2
Authors
+ Engineering and Physical Sciences Research Council
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- Funder identifier:
- https://ror.org/0439y7842
- Publisher:
- Springer
- Journal:
- Earth Systems and Environment More from this journal
- Publication date:
- 2026-01-20
- Acceptance date:
- 2025-12-30
- DOI:
- EISSN:
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2509-9434
- ISSN:
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2509-9426
- Language:
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English
- Keywords:
- Pubs id:
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2357043
- Local pid:
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pubs:2357043
- Deposit date:
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2026-01-08
- ARK identifier:
Terms of use
- Copyright holder:
- Khan et al.
- Copyright date:
- 2026
- Rights statement:
- © The Author(s) 2026. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.
- Licence:
- CC Attribution (CC BY)
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