open access

https://hdl.handle.net/2115/75198

When spring ephemerals fail to meet pollinators : mechanism of phenological mismatch and its impact on plant reproduction

英語

spring ephemeral

2019-06-04

Royal Society

Proceedings of the royal society b-biological sciences

286(1904)

20190573

The flowering phenology of early-blooming plants is largely determined by snowmelt timing in high-latitude and high-altitude ecosystems. When the synchrony of flowering and pollinator emergence is disturbed by climate change, seed production may be restricted due to insufficient pollination success. We revealed the mechanism of phenological mismatch between a spring ephemeral (Corydalis ambigua) and its pollinator (overwintered bumblebees), and its impact on plant reproduction, based on 19 years of monitoring and a snow removal experiment in a cool-temperate forest in northern Japan. Early snowmelt increased the risk of phenological mismatch under natural conditions. Seed production was limited by pollination success over the 3 years of the pollination experiment and decreased when flowering occurred prior to bee emergence. Similar trends were detected on modification of flowering phenology through snow removal. Following snowmelt, the length of the pre-flowering period strongly depended on the ambient surface temperature, ranging from 4 days (at greater than 7 degrees C) to 26 days (at 2.5 degrees C). Flowering onset was explained with an accumulated surface degree-day model. Bumblebees emerged when soil temperature reached 6 degrees C, which was predictable by an accumulated soil degree-day model, although foraging activity after emergence might depend on air temperature. These results indicate that phenological mismatch tends to occur when snow melts early but subsequent soil warming progresses slowly. Thus, modification of the snowmelt regime could be a major driver disturbing spring phenology in northern ecosystems.

学術雑誌論文

Accepted Manuscript

0962-8452