Abstract Detail

The impact of climate change on plants and their interactions with pollinators

Mulder, Christa [1], Kornhauser, Kara [2], Diggle, Pamela [3], Schaub, Eileen [4], Spellman, Katie [5].

Where have all the flowerflies gone? Multiple drivers of flowering phenology of understory shrubs alter overlap with pollinators in interior Alaska.

The potential for mismatches in the timing of flower availability and pollinator activity is high in areas with short growth seasons, where flowering is highly synchronous (both within and between individuals).  In interior Alaska the main drivers of flowering date are temperature in the initiation year (the year before flowering, when buds are preformed), timing of ground thaw in the flowering year, and temperature in the flowering year. We evaluated the relative importance of these factors for seven understory shrubs and found that while all species advanced flowering in response to earlier ground thaw, responses to warmer temperatures in the initiation year ranged from delays to no effect while responses to warming in the flowering year ranged from no effect to advances. We use that information to predict shifts in co-flowering patterns under different weather scenarios for successive years. Next, we evaluated pollination in experimental arrays of Viburnum edule, an early-flowering shrub that flowers synchronously (within a 2-week period at the population level) but shows large shifts in phenology between years (up to 3 weeks). In both 2020 and 2021 early-flowering branches received fewer visits from pollinators and fewer pollen grains than branches that flowered a week later, and the number of visitors to early-flowering branches was much lower in the early year (May 28-30 2020) than at any other time. This was driven by low numbers of syrphid (flower) flies (Syrphidae), the most common pollinators. Pollinator community similarity across years was explained by calendar date, suggesting that a shift to earlier flowering as spring continues to advance and especially as ground thaw occurs earlier may result in reduced pollination for some species. Finally, we discuss the implications for pollination of co-flowering species with different phenological drivers.

1 - University of Alaska Fairbanks, Institute of Arctic Biology, PO Box 757000, 2140 Koyukuk Drive, University of Alaska Fairbanks, Fairbanks, AK, 99775-7000, United States
2 - University Of Alaska Fairbanks, PO Box 81245, Fairbanks, AK, 99708, United States
3 - University Of Connecticut, Department Of Ecology And Evolutionary Biology, Storrs, CT, 6269, United States
4 - 13 Country Way, Bethel, CT, 06801, United States
5 - University of Alaska Fairbanks, International Arctic Research Center, 2160 Koyukuk Drive, Fairbanks, AK, 99775-7340, USA

boreal forest
bud preformation
trophic mismatch
solitary bees
syrphid flies
ground thaw.

Presentation Type: Symposium Presentation
Number: S3006
Abstract ID:628
Candidate for Awards:None

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