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Anthropogenic climate change is altering interactions among numerous species, including plants and pollinators. Plant-pollinator interactions, crucial for the persistence of most plant and many insect species, are threatened by climate change-driven phenological shifts. Phenological mismatches between plants and their pollinators may affect pollination services, and simulations indicated that these mismatches may reduce floral resources available to up to 50% of insect pollinator species. Although alpine plants rely heavily on vegetative reproduction, seedling recruitment and seed dispersal are likely to be important drivers of alpine community structure. Similarly, advanced flowering may expose plants to increased risk of frost damage and shifted soil moisture regimes; phenologically advanced plants will experience these environmental factors differently, which may alter their floral resource production. These effects may be dependent upon topography. Some species of alpine plants on the Niwot Ridge have displayed advanced phenology under treatments of advanced snowmelt (Forrester, 2021). However, little is understood about how these differences in distribution and phenology affect pollinator community composition and plant fecundity. Here we strive to examine how experimentally-induced changes in the timing of flowering and number of flowers produced by plants impact plant-pollinator interactions and seed set. We also ask how topography and the number of flowers interact with early snowmelt to affect pollination rates and the diversity of pollinating insects. Finally, we ask how seed set of Geum rossii is affected by pollinator visitation at different times of the season, under experimentally advanced snowmelt versus unmanipulated snowmelt, and with visitation by different insect taxa. In summer 2020, we found that plots with advanced phenology experienced peaks in pollinator visitation rates and pollinator diversity earlier than plots with unmanipulated snowmelt. We expect this to be because of the advanced floral phenology of certain key species in these plots. References: Forrester, C.C. (2021). Advancing, Using, and Teaching Climate Change Ecology Research. [Doctoral dissertation, University of Colorado, Boulder]. ProQuest Dissertations and Theses.
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This content will become publicly available on September 30, 2026
Phenological shifts in plants and pollinators over a century disrupt interaction persistence
Mutualistic interactions between plants and pollinators play an important role in supporting biodiversity and ecosystem stability. However, these interactions are increasingly threatened by climate change, which can alter the phenology of species and cause temporal mismatches between interacting partners. Leveraging historical and contemporary datasets collected more than a century apart, we investigated phenological shifts in plants and pollinators and the impact of changes in temporal overlap of the interaction partners on the persistence of their interactions. We found that generally, the onset of flowering and insect activity started earlier and has lasted longer in the present. We also found that greater temporal overlap of plant and pollinator species predicted a higher probability of persistence of their interaction between time periods. Our results document phenological shifts over a century, and emphasize the importance of maintaining phenological matching for the persistence of plant-pollinator interactions. This illustrates the value of historical data sets for understanding long-term ecological dynamics in the face of accelerating environmental change.
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- Award ID(s):
- 2102974
- PAR ID:
- 10630281
- Publisher / Repository:
- The American Naturalist
- Date Published:
- Journal Name:
- The American naturalist
- ISSN:
- 0003-0147
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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