Speaker
Description
In temperate zones, warmer springs shift leaf-out and flowering to earlier dates. Likewise, phenology shifts affect water and carbon cycles, influencing the climate system. Despite progress in understanding phenology-climate dynamics, gaps remain on how weather extremes impact phenology, especially using long-term and ground-based data, which offer detailed information about species that satellite images cannot capture. Our goal is to assess how extreme spring warmth and drought affect plant phenology, focusing on the roles of growth form, phenological niche, and strategy.
In this study, we compiled ground-based observations of first leaf-out (FLO) and first flowering day (FFD) from four monitoring networks: NatureWatch (Canada), PEP725 (Europe), NPN (USA), and Chronicle of Nature Calendar (Russia). We evaluated the relationship between phenology and extremes using Generalized additive models. We estimated temperature, precipitation, and phenology anomalies as annual deviation from long-term mean spring climate and date of FLO and FFD. We modeled phenology anomalies as a function of climate anomalies. Growth forms (herbs, shrubs, and trees); phenology strategies (Proteranthous: flowers appear before the leaves. Hysteranthous: leaves appear before the flowers); and phenological niche were added as covariates.
Our results show a differing pattern among the growth forms and phenology strategies. Warmer-than-average temperatures do not advance the FLO and FFD events in trees, whereas for herbs and shrubs, the events occur earlier. In trees, this relationship is consistent in both phenology strategies; however, in shrubs, temperature anomalies affect more to proteranthous than hysteranthous species. For all growth forms, anomalies in precipitation delay the FLO and FFD, and the effect is stronger in interaction with temperature anomalies. Furthermore, spring-flowering species respond more strongly to temperature and precipitation anomalies than summer-flowering species.
| Status Group | Doctoral Researcher |
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