Scientists and volunteers partner to explore poplar phenology and vulnerability to climate change

Background/Question/Methods: Connecting genomic variation to functional traits under ecologically relevant environments requires an extensive phenotyping effort. At the same time, large-scale environmental issues, such as global climate change, require landscape studies on foundational species that expand beyond genotype-phenotype mapping under simplified greenhouse and common garden experiments. Such studies need both remote-sensing platforms capable of measuring plant functional variation and spatially distributed volunteers who can make ground-based observations confirming phenological state. To explore benefits and challenges for this joint approach, we initiated a “citizen science” project (PopClock) and formed partnerships with three established citizen science phenology programs in the U.S. and Canada—National Phenology Network (NPN), Project Budburst and Plant Watch. We are focusing on two widely distributed species (Populus tremuloides and P. balsamifera), which often form large homogenous stands, making it easier to account for spatial variability in phenology within a satellite pixel. Our partners are recruiting volunteers (citizen scientists) and providing online and offline systems for data entry. Volunteers are asked to make multiple observations of one or both of the target species, noting dates of spring leaf emergence and fall color change. Their observations are being compared to indices calculated from the Moderate Resolution Imaging Spectrometer (MODIS). Ultimately, this comparison will be used to create accurate maps of “green-up” and “green-down,” which in turn will be integrated with genetic information to visualize the landscape surface of adaptive variation under both current and projected climates.

Results/Conclusions: Citizen scientist recruitment began in winter 2013 through email blasts to existing partners’ members and promotion on partners’ websites. This initial effort yielded fairly low response, possibly because of the limited involvement of citizen scientists in the research process (only contributing to data collection); little to no direct contact between project scientists and volunteers, and difficulty identifying one of the targeted species (P. balsamifera). With NPN, we are addressing these challenges using a targeted campaign, training webinars with project scientists on species identification, and additional sharing of project findings with PopClock volunteers. Where appropriate, NPN is also supporting local community leaders (e.g., agriculture extension agents) who work directly with groups of volunteers on data collection. Overall, this project will provide a better understanding of how to maintain engagement of citizen scientists over a large geographic area and extended time period and how such engagement impacts their understanding of how plants respond to environmental change.