Miller Chelsea N, Stuble Katharine L
Holden Arboretum Kirtland Ohio USA.
The University of Akron Akron Ohio USA.
Ecol Evol. 2024 Dec 16;14(12):e70700. doi: 10.1002/ece3.70700. eCollection 2024 Dec.
As plants continue to respond to global warming with phenological shifts, our understanding of the importance of short-lived heat events and seasonal weather cues has lagged relative to our understanding of plant responses to broad shifts in mean climate conditions. Here, we explore the importance of warmer-than-average days in driving shifts in phenophase duration for spring-flowering woodland herbs across one growing season. We harnessed the combined power of community science and public gardens, engaging more than 30 volunteers to monitor shifts in phenology (documenting movement from one phenophase to the next) for 198 individual plants of 14 species twice per week for the 2023 growing season (March-October) across five botanic gardens in the midwestern and southeastern US. Gardens included the Holden Arboretum, Kirtland, OH; Dawes Arboretum, Newark, OH; Chicago Botanic Garden, Glencoe, IL; Missouri Botanical Garden, St. Louis, MO; and Huntsville Botanical Garden, Huntsville, AL. We tested: (1) that higher-than-average daily temperatures (deviation from 30-year historical mean daily temperatures for each location) would be related to truncated phenophase durations; and (2) that phenophase durations would vary among species. Our findings support both hypotheses. We documented significant inverse relationships between positive deviations in daily temperature from historic means (e.g., warmer-than-average days) and durations of three reproductive phenophases: "First Bud," "First Ripe Fruit," and "Early Fruiting." Similar (non-significant) trends were noted for several other early-season phenophases. Additionally, significant differences in mean phenophase durations were detected among the different species, although these differences were inconsistent across plant parts (vegetative, flowering, and fruiting). Results underscore the potential sensitivity of understory herb reproductive phenophases to warmer-than-average daily temperatures early in the growing season, contributing to our understanding of phenological responses to short-term heat events and seasonal weather cues.
随着植物继续通过物候变化来应对全球变暖，我们对短期高温事件和季节性天气线索重要性的理解，相对于我们对植物对平均气候条件广泛变化的反应的理解而言，一直滞后。在此，我们探讨了高于平均温度的日子在推动一个生长季节中春季开花林地草本植物物候期持续时间变化方面的重要性。我们利用了社区科学和公共花园的联合力量，在2023年生长季节（3月至10月），让30多名志愿者每周两次监测美国中西部和东南部五个植物园中14个物种的198株个体植物的物候变化（记录从一个物候期到下一个物候期的转变）。这些花园包括俄亥俄州柯克兰的霍尔登树木园；俄亥俄州纽瓦克的道斯树木园；伊利诺伊州格伦科的芝加哥植物园；密苏里州圣路易斯的密苏里植物园；以及阿拉巴马州亨茨维尔的亨茨维尔植物园。我们测试了：（1）高于平均水平的每日温度（偏离每个地点30年历史平均每日温度）与缩短的物候期持续时间相关；以及（2）物候期持续时间在不同物种之间会有所不同。我们的研究结果支持了这两个假设。我们记录了每日温度相对于历史均值的正偏差（例如，高于平均温度的日子）与三个生殖物候期的持续时间之间存在显著的负相关关系：“第一芽”、“第一熟果”和“早期结果”。对于其他几个早季物候期，也观察到了类似（不显著）的趋势。此外，在不同物种之间检测到了物候期平均持续时间的显著差异，尽管这些差异在植物的不同部分（营养、开花和结果）并不一致。研究结果强调了林下草本植物生殖物候期对生长季节早期高于平均温度的每日温度的潜在敏感性，有助于我们理解对短期高温事件和季节性天气线索的物候反应。
