Abstract Detail


Mulder, Christa [1], Diggle, Pamela [2], Schaub, Eileen [3].

Slowing Down and Speeding Up: Contrasting Phenological Responses of Two Vaccinium Species to Experimental Warming in the Year Before Flowering.

While an advance in the timing of flowering is one of the most common responses to a warming climate, some plant species show little or no response. In many temperate and almost all boreal plant species, the initiation and early development of flower buds occurs in the year before flowering. If timing of flower initiation and rate of development in the initiation year are altered by warming, we would expect altered flowering phenology the following spring. We experimentally warmed Vaccinium vitis-idaea (lowbush cranberry) and Vaccinium uliginosum (blueberry) in a range of boreal forest sites in Interior Alaska using open-topped chambers. We employed a full factorial design with warming in the initiation year, flowering year, neither, or both, and evaluated developmental stage at the end of the initiation year and flowering phenology in the spring of the second and third year.  For cranberry, elevated temperatures in the initiation year resulted in a delay in flowering while warming in the year of flowering resulted in an advance in flowering. Consistent with this, scanning electron microscopy revealed that flower buds were less advanced in warmed plots than in control plots in the fall of the initiation year. Natural variation between sites in temperature gave similar results: sites with greater early-season depth of thaw and higher temperatures in the initiation year had delayed flowering while the opposite was true in the year of flowering. In contrast, blueberry showed little response to experimental warming in either the initiation or the flowering year, but when evaluating natural variation between sites advanced flowering was correlated with warm temperatures in both the initiation year and flowering year. These results may explain why there has been little change in flowering phenology of cranberry at high latitudes over the past decades, but an increase in variability of flowering phenology in blueberry.

Related Links:
Mulder Lab web page on this project

1 - University of Alaska Fairbanks, Institute of Arctic Biology, Irving I, 903 N Koyukuk Drive, Fairbanks, AK, 99775, USA
2 - University Of Connecticut, Department Of Ecology And Evolutionary Biology, Storrs, CT, 6269, United States
3 - University of Connecticut, Department of Ecology and Evolutionary Biology, Storrs, CT, 06269, USA

climate change
boreal forest

Presentation Type: Oral Paper
Session: ECO1, Ecology 1: Phenology
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 10:00 AM
Number: ECO1001
Abstract ID:344
Candidate for Awards:None

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