Late-Bloomers

Location: All of Alaska

Description: The Late Bloomers project is looking for observations of flowers blooming at unusual times in late summer or fall throughout Alaska. We have been finding a weird signal in arctic and boreal plant responses to warmer temperatures and longer growing seasons, and think it might be because some species are busting their buds in the fall, making them delayed in the spring. Have you seen wild rose or cranberry species flowering late in the fall, and you think, "man, little flower, why are you doing that? Don't you know the snow is coming??" All these woody plants pre-form their buds for the next year, but we think there might be something to longer summers leading to these buds being able to now develop a little too far along. University of Alaska Fairbanks and University of Connecticut researchers need your observations of Alaskan plants that seem to be flowering way too late in the fall.

Background: For plants, the timing of flowering is a critical part of their life cycle. If plants flower too early or too late, they could miss the timing of their important pollinators or the timing of when animals like migrating birds come through and disperse their fruit. Many flowering plants bloom earlier in response to warmer temperatures, and earlier flowering times of plants is often considered a fingerprint of global warming. Some species, however, either do not respond or delay flowering when there are warmer temperatures. What explains these exceptions to the common association of earlier flowering with warming temperatures? It could be due to several things: 1) responses to other cues like photoperiod or soil moisture that may oppose the effects of warming, 2) increased snow fall that may result in delayed snow melt, or 3) warmer winter temperatures that may result in unmet chilling requirements that delay when a plant emerges from dormancy. We think that another reason may help explain why some species seem to break the rule: the timing of bud formation and its interaction with warmer temperatures and longer growing seasons. Shrubs, trees and berry plants in the northern latitudes start to develop their flower buds one or two years before they are needed. In a year with a longer than usual growing season, a first set of buds may open in spring, and then a second set of buds, intended for the next year, may open late in late summer or fall (a “late bloomer,” as we are calling it). The following spring, even if the timing of spring is early, these plants could take longer to flower as they wait to develop their next cohort of flower buds. University of Alaska Fairbanks and University of Connecticut researchers are looking for your help to make observations and find patterns in late bloomers.

Observing Guidance:

• Please take at least two photos of the late blooming flower for the post, one up close so that the species can be identified, and one approximately 3 ft away from the flower, so we can get a sense of the proportion of flowers that are blooming on the plant and nearby plants.
• In the notes, please record the latitude and longitude, and an estimate of the percent of the buds on the plant that have popped open in the area. To do this, imagine a square area with the late blooming flower at the center that is the length and width of your arms fully spread out. What percent of the buds in the square have popped: less than 1%, 1-5%, 6-10%, greater than 10%?
• Make other notes you think are relevant in your post, like unseasonable weather, pollinators or insects being observed, or proximity to trails or buildings.
• All observations of unusually late flowers are welcome, but of particular interest are observations of August-October flowers on the following species: Bearberry (Arctostaphylos rubra), Labrador tea (Rhododendron groenlandicum), Prickly rose (Rosa acicularis), cloudberry (Rubus chamaemorus), Buffalo berry (Shepherdia canadensis), Lowbush cranberry (Vaccinium vitis-idaea), Lowbush blueberry (Vaccinium uliginosum), and Highbush cranberry (Viburnum edule).

Source Data: This project will utilize LEO posts to see if there are any geographic or climatic patterns in late blooming plant observations, and they will be used in conjunction with plant developmental information from cranberry (Vaccinium vitis-idaea) buds collected throughout Alaska. These results will also be supported by an open top chamber experiment being conducted in the Bonanza Creek Long Term Ecological Research Station at UAF where some small woody plant species are getting artificially warmed and some are not to try to isolate changes in temperature as a mechanism for pre-formed bud developmental rates. Outputs: Contribution to published report or paper.

Project Updates: Pending

Resources:

Project information and observing guidance can be found at the Late Bloomers Project Website

Mulder, C.P.H., D.T. Iles and R.F. Rockwell. 2017. Increased variance in temperature and lag effects alter phenological responses to rapid warming in a subarctic plant community. Global Change Biology 23(2): 801-814. DOI: 10.1111/gcb.13386 Contacts: Katie Spellman, University of Alaska Fairbanks, klspellman@alaska.edu (Project community science coordinator) Christa Mulder, University of Alaska Fairbanks, cpmulder@alaska.edu (Principal Investigator) Pam Diggle, University of Connecticut, pamela.diggle@uconn.edu (Principal Investigator)