2025-06-30 ミシガン大学
<関連情報>
- https://news.umich.edu/seasonal-allergies-caused-by-fungal-spores-now-start-three-weeks-earlier-under-climate-change/
- https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GH001323
真菌の胞子シーズン、気候変動の20年間で全米に拡大 Fungal Spore Seasons Advanced Across the US Over Two Decades of Climate Change
Ruoyu Wu, Yiluan Song, Jennifer R. Head, Daniel S. W. Katz, Kabir G. Peay, Kerby Shedden, Kai Zhu
GeoHealth Published: 30 June 2025
DOI:https://doi.org/10.1029/2024GH001323
Abstract
Phenological shifts due to climate change have been extensively studied in plants and animals. Yet, the responses of fungal spores—organisms important to ecosystems and major airborne allergens—remain understudied. This knowledge gap limits our understanding of their ecological and public health implications. To address this, we analyzed a long-term (2003–2022), large-scale (the continental US) data set of airborne fungal spores collected by the US National Allergy Bureau. We first pre-processed the spore data by gap-filling and smoothing. Afterward, we extracted 10 metrics describing the phenology (e.g., start and end of season) and intensity (e.g., peak concentration and integral) of fungal spore seasons. These metrics were derived using two complementary but not mutually exclusive approaches—ecological and public health approaches, defined as percentiles of total spore concentration and allergenic thresholds of spore concentration, respectively. Using linear mixed-effects models, we quantified annual shifts in these metrics across the continental US. We revealed a significant advancement in the onset of the spore seasons defined in both ecological (11 days, 95% confidence interval: 0.4–23 days) and public health (22 days, 6–38 days) approaches over two decades. Meanwhile, total spore concentrations in an annual cycle and in a spore allergy season tended to decrease over time. The earlier start of the spore season was significantly correlated with climatic variables, such as warmer temperatures and altered precipitations. Overall, our findings suggest possible climate-driven advanced fungal spore seasons, highlighting the importance of climate change mitigation and adaptation in public health decision-making.
Key Points
- In the United States, the onsets of both ecological and allergenic fungal spore seasons advanced from 2003 to 2022, with declined intensity
- Earlier onset of ecological spore seasons was correlated with higher temperature and lower precipitation
- Lower intensity of spore season was correlated with lower precipitation levels
Plain Language Summary
Climate change is shifting the timing of many life cycle events, but we know little about how the seasonal cycles of fungal spores—reproduction units of fungi in ecosystems and a major allergen source to humans—are affected. Using spore concentration data across the US from 2003 to 2022, we studied how fungal spore seasons changed. We estimated the start and end of spore seasons, as well as their intensity, from two perspectives: one based on the percentage of annual total spore counts (ecological) and another focusing on allergenic thresholds (public health). Over two decades, we identify that fungal spore seasons started earlier by 11 days from an ecological perspective and 22 days from a public health perspective. However, the total spore emission over a year declined. We further show that variations in spore seasons were linked to temperature and rainfall patterns. This research underscores the biological impacts of climate change and informs adaptations of public health.
