Current Research

Funky Flowers

(not the official name - but that one is really boring)

In collaboration with Pam Diggle and Eileen Schaub, University of Connecticut

Most research on flowering phenology focuses on the year in which plants flower, but temperate, subarctic, and arctic plants all initiate flower buds at least a year before the plants flower (in some cases several years). How does temperature in the year(s) PRIOR to flowering affect the rate of flower development? A previous study from the Mulder lab (Mulder et al. 2016) conducted in northern Manitoba showed that when it was warm the year prior to flowering, flowering was actually delayed. What could drive such an unexpected response?

We are evaluating the impact of warmer temperatures in the year prior to flowering by putting out open-topped chambers (OTCs) at 19 sites in 2 habitats in interior Alaska, and tracking responses of 7 plants species. We do this by sampling plants in OTCs and control plots throughout the summer and using scanning electron microscopy to track development of preformed buds. We also record flowering phenology.

Why It Matters

One of the biggest concerns under global warming is that while many species shift their phenology in the same direction (e.g., earlier flowering, earlier nesting, earlier changes from winter to summer pelage), they do not do so at the same rate, resulting in trophic (and other) mismatches. If changes in development of leaf primordia affect or limit plant responses to warming, and especially if they involve threshold responses to temperature (e.g., cumulative temperatures at which flowering in fall is induced, or flower initiation fails), then we may see the rapid development of larger mismatches as boreal forest continues to warm.

Outreach

In collaboration with Katie Spellman we have also developed a citizen science network called LateBloomers. Participants report unusual phenological events (such as flowering at the wrong time of year) and collect buds of lowbush cranberry (Vaccinium vitis-idaea) across the state.

Publications relevant to this study:

Mulder et al. 2016, Diggle and Mulder 2019, Schaub, Mulder and Diggle 2021

Funding: National Science Foundation (DEB and Bonanza Creek LTER site).

A preformed bud in July of the year prior to when it would have flowered (had we not collected it). Photo: P. Diggle.

Putting together OTCs

Pam sets up an OTC in mixed white spruce - deciduous habitat

An OTC in black spruce habitat

Watch an animation of this process.

Winterberry / Arctic Harvest - public participation in scientific research

In collaboration with Katie Spellman (PI), Elena Sparrow, Sarah Stanley, Doug Cost, Jasmine Shaw and Chris Villano.

This is a science education study (Arctic Harvest, led by Spellman) within an ecological study (Winterberry, led by Mulder) - or the other way around, depending on your perspective.

Winterberry: the fate of fleshy fruits in fall and winter

How do shifts in climate affect the fate of fleshy fruits (“berries”) and timing of their loss from plants in fall and winter across Alaska? Numerous studies have established that berries retained on the plant over the winter are critical in meeting the nutritional needs of boreal and arctic animals such as foxes, bears, voles, grouse, ptarmigan, and migrating geese. Berry species are also of great cultural and nutritional importance to communities across Alaska and Canada, especially in rural communities where other sources of fresh fruit are lacking or extremely expensive. Yet we lack even the most basic information on retention of berries following ripening. Arctic and boreal habitats are experiencing earlier springs, which leads to earlier flowering and earlier berry ripening in many of these species. Will earlier springs, warmer or wetter summers, and extended autumns result in a greater loss of berries to consumers or decomposers, leaving fewer berry resources for animals (including people) that use them in winter and spring?

To address this question we are used a citizen science network with locations across Alaska. We focused on four species that retain a high proportion of their berries, are widely distributed and in high abundance across the state, and are culturally and nutritionally important: Vaccinium vitis-idaea (lowbush cranberry or lingonberry), Viburnum edule (highbush cranberry), Empetrum nigrum (crowberry), and prickly rose (Rosa acicularis). Participants selected a focal species and track berries in fall and winter for at least 2 seasons. Data were used to construct a natural history of berry loss for these four species, and will be combined with climate data to build models that predict changes in the retention of berries throughout fall, winter and spring across the state under a changing climate.

You can read all about it in our first Winterberry paper: Mulder et al. 2021.

Arctic Harvest: Engaging diverse groups in scientific research

Citizen science programs often struggle to attract participation of minority groups and people living in rural communities. In Alaska, the vast majority of those who participate in such projects are adult males, mostly hunters and fishermen involved in wildlife monitoring projects. The majority of participants in our previous citizen scientist networks were white, urban, and well-educated. There are trade-offs between meeting the needs of participants (e.g. learning, sense of contribution, empowerment, connection to local concerns) and the needs of scientists (producing publishable datasets that can address large-scale scientific questions). As a result, citizen science research often produces excellent data or deeply engages participants, but seldom both.

In Arctic Harvest we evaluate whether a contributory citizen science program can be supplemented to reduce the trade-offs between individuals / community learning and broad scientific outcomes and engage a greater range of participants. We focus on after-school groups and other informal learning groups (e.g., Girl Scouts) and use the Winterberry Project to compare three different treatments:

1) A “basic” citizen science delivery method, which involves a single visit (in person or online) to a youth group. There is little interaction during data collection, and a single data discovery session.

2) A “supported” delivery method which includes multiple in-person visits by a scientist and a mentor for the youth group leader, a “community berry night” aimed at engaging the wider community, continued support from the team to the group leader, and more in-depth data discovery.

3) A “storytelling” delivery method in which the level of effort is similar to the supported method, but concepts, hypotheses, and results are all framed in a story-telling context. Community members, especially elders, are included in the story telling, and the data discovery process includes an exercise in which youth come up with solutions to several future scenarios.