Global study reveals phenological divergence between plants and animals under climate change

A collaborative study reveals the distinct mechanisms by which plants and animals respond to climate change in their life-cycle phenology. This research, led by Piao Shilong’s team and Zhang Yao’s team from the Institute of Carbon Neutrality at Peking University, provides comprehensive global-scale evidence on the asynchronous phenological changes between plants and animals.

Climate change has altered the timing of recurring biological cycles in both plants and animals. Asynchrony in phenological changes between plants and animals can disrupt trophic interactions, such as food chains, and ultimately threaten ecosystem stability and functionality.

While numerous phenological observations have been documented for plants and animals, most studies have been limited to regional or national scales. This research, now published in Nature Ecology & Evolution, synthesizes phenological observations on a global scale, offering critical insights into the impact of climate change on phenological synchrony across landscapes.

The research team compiled a global phenological dataset, encompassing 451,956 plant phenological time series (covering 1,629 species or genera across 248 events) and 43,857 animal phenological time series (covering 949 species or genera across 432 events).

The later the plant phenophase, the more it advances over time: Analysis indicates that plant phenophases during spring and summer predominantly advanced with shortened intervals between consecutive events. Nearly 30% of spring-summer phenological shifts in plants are influenced by prior events, creating a time-dependent response where warming effects accumulate and amplify over seasons.

Animals show less pronounced phenological changes at the start of the active season than plants: Animals show no consistent time-dependent trends across different phenological events. The first occurrences of Aves, Mammalia and Amphibia are delayed at various rates, while that for Insecta exhibits a slight advancement rate. These shifts are much weaker than spring leafing or flowering of plants.

Temporal dependency of phenophases in plants: The research found a strong temporal linkage between neighboring plant phenophases during spring and summer, with a clear trend towards shortening of intervals, potentially due to the increased plant productivity caused by warming and carbon dioxide fertilization, shortening the time required to produce foliage, flowers or fruits.

This study underscores the intrinsic connections between phenological events in plants and the contrasting mechanisms in animals, shedding light on the increasing asynchrony caused by climate change. The overall advancement of late-season phenophases for plants is more significant than that for animals.

Such discrepancies may indicate different (relative importance of) external and internal drivers for plant and animal phenology. The findings provide a new perspective for understanding trophic-level mismatches and predicting ecosystem stability under ongoing global warming.