Impact of summer defoliation and winter–spring warming on pre-spring carbon availability and spring phenology in sessile oak and Scots pine saplings
Seasonal climate warming affects temperate plant phenology differently. Early winter warming can delay dormancy release and budburst due to insufficient chilling, while late winter or spring warming advances budburst. Additionally, the influence of pre-spring non-structural carbohydrate (NSC) availability on leaf phenology remains poorly understood. We explored the effects of previous late-summer defoliation and winter-spring warming on NSC dynamics and spring leaf phenology in two species: deciduous sessile oak with low chilling sensitivity and evergreen Scots pine with intermediate chilling sensitivity. We observed species-specific responses of leaf phenology to warming and defoliation. Winter warming delayed leaf unfolding in pine but not in oak, likely reflecting the greater chilling requirement of the pine. Defoliation significantly reduced pre-spring NSC levels in twigs and roots of both species, and led to earlier needle emergence in pine, with no impact on oak's leaf out date. Our findings indicate a dual dependency of pine leaf unfolding on temperature and internal carbon reserves, suggesting that defoliation, e.g. through herbivory or diseases, affects the following year's spring phenology and leaf growth in evergreen species but not in deciduous trees. These findings are important for understanding the adaptive strategies of different plant functional types under uneven warming conditions.
Authors
- Yann Vitasse (ORCID: https://orcid.org/0000-0002-7454-505X)
- Zhongmin Hu (ORCID: https://orcid.org/0000-0002-4801-5370)
- Mai‐He Li (ORCID: https://orcid.org/0000-0002-7029-2841)
- Lei Wang (ORCID: https://orcid.org/0000-0002-8253-7295)
- Hong Shi He (ORCID: https://orcid.org/0000-0002-3983-2512)
- Decai Gao (ORCID: https://orcid.org/0000-0003-0545-4020)
- Constantin M. Zohner (ORCID: https://orcid.org/0000-0002-8302-4854)
- Shengwei Zong (ORCID: https://orcid.org/0000-0002-3583-6110)
- Yue Yang (ORCID: https://orcid.org/0000-0001-8914-8543)
- Yanli Zhang (ORCID: https://orcid.org/0000-0003-1738-4672)
- Ao Wang (ORCID: https://orcid.org/0000-0002-0140-8468)
- Haibo Du (ORCID: https://orcid.org/0000-0001-6195-085X)
- Zhengfang Wu
Institutions
- University of Bern (CH)
- Oeschger Centre for Climate Change Research (CH)
- Northeast Normal University (CN)
- Chinese Academy of Sciences (CN)
- Hainan University (CN)
- Swiss Federal Institute for Forest, Snow and Landscape Research (CH)
- ETH Zurich (CH)
- Northeast Institute of Geography and Agroecology (CN)
- Department of Ecology and Environment of Hainan Province (CN)
- SystemsX.ch (CH)
- Institute of Geographic Sciences and Natural Resources Research (CN)
- Hebei University (CN)
- Jiangxi Agricultural University (CN)
- University of Missouri (US)
Publication Details
- Journal
- Tree Physiology
- Published
- 2025-11-06
- DOI
- https://doi.org/10.1093/treephys/tpaf144
- Primary Topic
- Plant Water Relations and Carbon Dynamics
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- National Natural Science Foundation of China
- Swiss Federal Institute for Forest, Snow and Landscape Research