An official website of the United States government
Climate change can lead to “secondary extinction risks” for plants owing to the decoupling of life-cycle events of plants and their pollinators (i.e., phenological mismatch). However, forecasting secondary extinction risk under future climate change remains challenging. We developed a new framework to quantify plants’ secondary extinction risk associated with phenological mismatch with bees using ca. 15,000 crowdsourced specimen records of Viola species and their solitary bee pollinators spanning 120 years across the eastern United States. We further examined latitudinal patterns in secondary extinction risk and explored how latitudinal variation in plant-pollinator specialization influence this risk. Secondary extinction risk of Viola spp. increases with latitude, indicating that future climate change likely will pose a greater threat to plant-bee pollinator networks at northern latitudes. Additionally, the sensitivity of secondary extinction risk to phenological mismatch with both generalist and specialist bee pollinators decreases with latitude: specialist bees display a sharper decrease at higher latitudes. Our findings demonstrate that existing conservation priorities identified solely based on primary extinction risk directly caused by climate change may not be sufficient to support self-sustaining populations of plants. Incorporating secondary extinction risk resulting from ecological mismatches between plants and pollinators into future global conservation frameworks should be carefully considered.
more »
« less
This content will become publicly available on October 7, 2026
Climate change intensifies plant–pollinator mismatch and increases secondary extinction risk for plants in northern latitudes
Climate change is altering the timing of species’ life-cycle events (i.e., phenology), but the rates of phenological shifts vary across taxa. These mismatches in phenological response may disrupt interactions between interdependent species, such as plants and their pollinators, which may lead to reduced plant reproduction via pollen limitation and thus contribute to secondary extinction risks for plants. However, secondary extinction risk is rarely assessed under future climate-change scenarios. Here, we used ca. 15,000 crowdsourced specimen records ofViolaspecies and their solitary bee pollinators, spanning 120 y across the eastern United States, and integrated climate data, phenological information, and species distribution models to quantify the risk of secondary plant extinction associated with phenological mismatch with their bee pollinators. We further examined geographical patterns in secondary extinction risk for plants and explored how their interactions between plants and generalist versus specialist pollinators influence such risk. Secondary local extinction risk ofViolaspp. increases with latitude, indicating that future climate change will pose a greater threat to plant–bee pollinator networks at northern latitudes. Additionally, the sensitivity of secondary local extinction risk to phenological mismatch with both generalist and specialist bee pollinators varies by latitude, with specialist bees showing a sharper decline at higher latitudes. Our findings demonstrate that existing conservation priorities based solely on primary extinction risk directly caused by climate change may be insufficient to support self-sustaining populations of plants. Thus, incorporating secondary extinction risk resulting from ecological mismatches between plants and pollinators into future global conservation frameworks should be carefully considered.
more »
« less
- PAR ID:
- 10688016
- Publisher / Repository:
- National Academy of Sciences
- Date Published:
- Journal Name:
- Proceedings of the National Academy of Sciences
- Volume:
- 122
- Issue:
- 40
- ISSN:
- 0027-8424
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Phenology, the timing of recurrent biological events, is a key mechanism by which species adapt or acclimatize to variable environmental conditions, including those influenced by climate change. Measurable traits, including the onset and end of activity, peak activity, and duration, characterize the phenology of life events, and could be significant predictors of trends in population abundance or stability in a changing climate. Bees provide critical pollination services, and understanding the covariates of bee phenological traits can refine predictions on the vulnerabilities of bees and their services to climate change. We paired 16 years of monthly bee survey data (2002-2019) with climate data for 74 bee species in dryland ecosystems of central New Mexico, USA. Contrary to the current paradigm of temperature as the key driver of insect phenology, twice as many bee species had phenological sensitivity to precipitation (39%) than to temperature (20%). Among phenological traits, the end date of active flying periods was most sensitive to climate. Of the 20% of bee species for which precipitation predicted activity end date, 73% ended activity later in wetter years. Fifteen bee species (~20%) had phenological traits sensitive to temperature, but temperature sensitivity was idiosyncratic, and only four species had earlier onset in warmer years, as expected from results in other biomes. Oligolectic (diet specialist) bee species began, peaked, and ended activity later in the year than polylectic (generalist) species, but phenological traits did not correlate with sociality. All phenological traits showed phylogenetic signal, suggesting evolutionary conservatism of phenology among the common bees of central New Mexico drylands. Finally, species with long activity durations were more common, had greater temporal stability in abundance from year to year, and were less likely to decline over time, perhaps because of their longer window for resource acquisition. Our results suggest that drier climates of the future may shift bee phenological activities toward earlier onset, peak, and end dates, that bees with short activity durations may be among the most sensitive to declines in future climates, and that both generalist and social bees may be able to resist or recover from climate change if they have long durations of flight activity.more » « less
-
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.more » « less
-
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.more » « less
-
Anthropogenic climate change represents one of the most serious threats to ecosystems in the 21st century. As temperatures increase, and precipitation patterns are altered, species need to respond to living in increasingly arid environments. The most noticeable responses to changing climate is for populations to shift spatially, typically upward in elevation and latitude, and phenologically, typically by becoming phenologically active earlier in the year. Variation in how individual organisms or populations respond to climate change can alter their ecological interactions. The timing of flowering is species specific, and when and with whom a plant flowers adjacent to can impact their reproductive success. Between trophic levels, the synchronous phenology of flowering plants and pollinators is critical for both plant and pollinator reproductive success. Plant-plant and plant-pollinator phenological synchrony is at risk of deterioration due to aridification, potentially decreasing ecosystem functioning across the globe. While the bulk of previous research on this issue has been conducted in humid systems, plant- pollinator phenological synchrony has been in understudied in dryland ecosystems, which encompass over 40% of land globally. In the following chapters, I leverage natural history data along spatial and temporal gradients to determine the impacts of climatic variation on plant-plant and plant-pollinator phenological synchrony. I find evidence that plant-plant phenological synchrony is sensitive to changes in community composition. Plant-pollinator phenological synchrony decreases with increasing aridity at the community level, but some species are better suited to future aridification than others. My dissertation highlights the importance of understanding phenological synchrony in dryland ecosystems using analytical techniques specifically suited to the stochastic nature of climate change in these systems.more » « less
