Space-for-Time Substitution to study changes in flowering phenology in herbaceous species is most reliable for early-flowering species

Anna Knapp; Wolfgang Matzke; Barbara Knickmann; Christine Römermann; Robert Rauschkolb

doi:10.1016/j.baae.2025.10.007

Space-for-Time Substitution to study changes in flowering phenology in herbaceous species is most reliable for early-flowering species

Anna Knapp (Corresponding author)
, Wolfgang Matzke
, Barbara Knickmann
, Christine Römermann
, Robert Rauschkolb (Corresponding author)

Publications: Contribution to journal › Article › Peer Reviewed

Abstract

Phenological events in plants are shifting worldwide in response to changes in climate. Studying long-term shifts of phenological events in plants using historical data can lead to a better understanding of processes driving phenological changes and a basis for predicting potential changes in the future. However, conducting such Time-for-Time Substitutions (TFTS), i.e., learning from the past to predict the future, remains rare due to limited availability of long-term data. An alternative method for understanding phenological change is the Space-for-Time Substitution (SFTS), in which the temporal gradient is reflected by a spatial gradient. We used historical phenological records of 17 herbaceous species from botanical gardens in Vienna covering a period of 150 years and data from 11 botanical gardens covering a spatial gradient to test the space-time equivalence. We fitted a linear-mixed effect model to test for differences between the two approaches (i.e., changes in time vs. changes in space) for analysing the associations between annual flowering onset dates and temperature. In addition, we examined the species-specific suitability of SFTS in regard to species' temporal niches. We showed that flowering advanced on average by seven days for a temperature increase of 1 °C, irrespective of the gradient considered. At the species level, however, we found that the known pattern that late-flowering species are less temperature-sensitive was not found with the SFTS dataset. The space-time equivalence was better fulfilled for early-flowering species than for late-flowering ones. This study contributes significantly to phenological research, as it demonstrated that the SFTS generally applied for herbaceous species. However, this method should always be used with caution for species-specific questions. In addition, it remains unclear to what extent the patterns found in botanical gardens are also found in less-controlled habitats.

Original language	English
Pages (from-to)	98-105
Number of pages	8
Journal	Basic and Applied Ecology
Volume	89
Early online date	20 Oct 2025
DOIs	https://doi.org/10.1016/j.baae.2025.10.007
Publication status	Published - Dec 2025

Funding

We are very grateful to Karl Fritsch from the Austria-wide phenological observation network for their initiative to collect phenological data in Vienna. Furthermore, we would like to express our deepest gratitude to Prof. Michael Kiehn (University of Vienna) for his valuable support in bringing people together and for his advice during the development of this work. We also thank all collectors of PhenObs data and especially thank Birgit Nordt (Berlin), Isabell Hensen (Halle a.d. Saale), Martin Freiberg (Leipzig), Janin Naumann (Jena), Anja Linstädter (Potsdam), Tomáš Koubek (Prague), Manzoor Shah (Srinagar), Alexandra Kehl (Tuebingen) and Eduardo Fernández-Pascual (Gijón) for coordinating their PhenObs sites. Finally, we thank all the gardeners working in the Botanical Gardens for their continuous efforts to look after the plants. We thank the iDiv Data & Code Unit for assistance with curation and archiving of the dataset. We acknowledge support through the PhenObs network, which is funded by the German Science Foundation (DFG) via the German Centre for Integrative Biodiversity research (iDiv) Halle-Jena-Leipzig (FZT 118) for the support of the FlexPool project (09159715) as well as the strategic project PhenObs (09159723).

Austrian Fields of Science 2012

106008 Botany

Keywords

Climate change
Flowering onset
Time-for-Time Substitution
Botanical garden

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10.1016/j.baae.2025.10.007Licence: CC BY 4.0

Cite this

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title = "Space-for-Time Substitution to study changes in flowering phenology in herbaceous species is most reliable for early-flowering species",

abstract = "Phenological events in plants are shifting worldwide in response to changes in climate. Studying long-term shifts of phenological events in plants using historical data can lead to a better understanding of processes driving phenological changes and a basis for predicting potential changes in the future. However, conducting such Time-for-Time Substitutions (TFTS), i.e., learning from the past to predict the future, remains rare due to limited availability of long-term data. An alternative method for understanding phenological change is the Space-for-Time Substitution (SFTS), in which the temporal gradient is reflected by a spatial gradient. We used historical phenological records of 17 herbaceous species from botanical gardens in Vienna covering a period of 150 years and data from 11 botanical gardens covering a spatial gradient to test the space-time equivalence. We fitted a linear-mixed effect model to test for differences between the two approaches (i.e., changes in time vs. changes in space) for analysing the associations between annual flowering onset dates and temperature. In addition, we examined the species-specific suitability of SFTS in regard to species' temporal niches. We showed that flowering advanced on average by seven days for a temperature increase of 1 °C, irrespective of the gradient considered. At the species level, however, we found that the known pattern that late-flowering species are less temperature-sensitive was not found with the SFTS dataset. The space-time equivalence was better fulfilled for early-flowering species than for late-flowering ones. This study contributes significantly to phenological research, as it demonstrated that the SFTS generally applied for herbaceous species. However, this method should always be used with caution for species-specific questions. In addition, it remains unclear to what extent the patterns found in botanical gardens are also found in less-controlled habitats.",

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AU - Knapp, Anna

AU - Matzke, Wolfgang

AU - Knickmann, Barbara

AU - Römermann, Christine

AU - Rauschkolb, Robert

PY - 2025/12

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AB - Phenological events in plants are shifting worldwide in response to changes in climate. Studying long-term shifts of phenological events in plants using historical data can lead to a better understanding of processes driving phenological changes and a basis for predicting potential changes in the future. However, conducting such Time-for-Time Substitutions (TFTS), i.e., learning from the past to predict the future, remains rare due to limited availability of long-term data. An alternative method for understanding phenological change is the Space-for-Time Substitution (SFTS), in which the temporal gradient is reflected by a spatial gradient. We used historical phenological records of 17 herbaceous species from botanical gardens in Vienna covering a period of 150 years and data from 11 botanical gardens covering a spatial gradient to test the space-time equivalence. We fitted a linear-mixed effect model to test for differences between the two approaches (i.e., changes in time vs. changes in space) for analysing the associations between annual flowering onset dates and temperature. In addition, we examined the species-specific suitability of SFTS in regard to species' temporal niches. We showed that flowering advanced on average by seven days for a temperature increase of 1 °C, irrespective of the gradient considered. At the species level, however, we found that the known pattern that late-flowering species are less temperature-sensitive was not found with the SFTS dataset. The space-time equivalence was better fulfilled for early-flowering species than for late-flowering ones. This study contributes significantly to phenological research, as it demonstrated that the SFTS generally applied for herbaceous species. However, this method should always be used with caution for species-specific questions. In addition, it remains unclear to what extent the patterns found in botanical gardens are also found in less-controlled habitats.

KW - Climate change

KW - Flowering onset

KW - Time-for-Time Substitution

KW - Botanical garden

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M3 - Article

SN - 1439-1791

VL - 89

SP - 98

EP - 105

JO - Basic and Applied Ecology

JF - Basic and Applied Ecology

ER -

Space-for-Time Substitution to study changes in flowering phenology in herbaceous species is most reliable for early-flowering species

Abstract

Funding

Austrian Fields of Science 2012

Keywords

Access to Document

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