Predicting the future:Using plant phenological research to manage ecosystems in an era of global change

Janet Prevéy, Research Ecologist, USGS Fort Collins Science Center and USFS Pacific Northwest Research Station

The importance of phenology

• Changes in phenology are among the most visible and sensitive indicators of climate change

• Shifts in phenology can have widespread and cascading impacts on ecosystem processes and human livelihoods

• Phenology is the study of seasonal biological events

Photo: Gary Bendig on UnsplashPhoto: Ryan Carpenter on UnsplashPhoto: Sergey Shmidt on UnsplashPhoto: Luca Bravo on Unsplash

Measuring phenological change

• Historical records are rare• Personal diaries

• Festival timing

• Cherry blossoms in Japan

• Modern records are more numerous and diverse:• Satellite imagery

• Long-term monitoring sites

• Phenocam images

• Herbarium records

• Crowd-sourced science

Using plant phenological research to manage ecosystems in an era of global change

• Harnessing the power of citizen science and herbarium records to predict shrub phenology

• Phenology forecasting tools for management and detection of invasive grasses

Changing phenology of culturally-important shrubs of the Pacific Northwest

In collaboration with:

USFS Pacific Northwest Research Station: Constance Harrington, Leslie Brodie

USDA California Climate Hub: Lauren Parker

Funding:

Project motivation

• There is a strong interest in preserving and restoring culturally-important plant species across the Pacific Northwest

• Significant food sources for grizzly bears, black bears, grouse, songbirds, deer, elk, etc.

• Warmer temperatures are shifting the ranges and advancing the timing of seasonal biological events around the world

• Changes in the timing of flowering and fruiting of food-producing shrubs can have cascading impacts on the ecosystem

Focal shrub species

Beaked hazelnutCorylus cornuta

Oregon grapeMahonia aquifolium

SalalGaultheria shallon

Photo credits: Wikipedia commons, T. Abe Lloyd

Black huckleberryVaccinium membranaceum

• We compiled a wealth of publically available data to allow us to make robust predictions based on manyobservations

Data sources

Map credit: Leslie Brodie

Changing phenology:Flowering and fruiting observations

• Repeated measurements of shrub phenology data are rare, so we estimated dates of flowering and fruiting from diverse data sources to examine how shrub phenology relates to seasonal temperatures.

Black huckleberry in fruit, 7/29/2018iNaturalist observation by Mitch Hurt

Black huckleberry in fruit, 8/3/1986University of Idaho, collection by Fred Johnson

• Matched locations of phenology observations to interpolated temperature data from Daymet from all observations

• Calculated thermal sum models for all species:

• Summed daily temperatures above 0℃ from January 1st through mean flowering and fruiting dates

• R packages: daymetr and phenor: https://khufkens.com/code/

Hufkens K., Basler J. D., Milliman T. Melaas E., Richardson A.D. (2018) An integrated phenology modelling framework in R: Phenology modelling with phenor. Methods in Ecology & Evolution. 9, 1 - 10.

Changing phenology:Historical climate data

Predicted dates of fruiting for black huckleberry in 2010

• Used thermal sum models and climate predictions to model future changes in phenology

• 15 CMIP5 model means for future climate: 2045 and 2085 and for 2 emissions scenarios: RCP 4.5 and RCP 8.5

Changing phenology: Future climate data

Changing phenology:Shifts in flowering by 2085 - RCP 8.5

Hazelnut Oregon grape Salal Black huckleberry

Flowering may advance 7 - 50 days by the 2085….

7 days

22 days

37 days

52 days

Fruiting may advance 10 - 55 days by the 2085….

7 days

22 days

37 days

52 days

Hazelnut Oregon grape Salal Black huckleberry

Changing phenology:Shifts in fruiting by 2085 - RCP 8.5

10 days

25 days

30 days

54 days

• Wilbur Bluhm recorded phenology data around Salem, Oregon for over 50 years:http://agsci-labs.oregonstate.edu/plantphenology/

• He recorded dates of Oregon grape flowering from 1960 – 2016

Have there been large shifts in phenology over the recent past astemperatures have warmed?

Flowering of Oregon grape has advanced an average of 50 days since 1960…….

R2 = 0.62p < 0.0001

• The timing of flowering and fruiting could advance by 7- 55 days by 2085

• The models can serve as a basis for targeted monitoring efforts to evaluate how climate change is actually impacting important shrub species

• The predictions can be used to identify geographic areas where climate change could significantly impact flowering and fruiting of edible shrubs, and help managers determine suitable locations for restoration projects.

Photo: OSU Special CollectionsPhoto: 2008 Ed Book Photo: U.S. Fish and Wildlife Service

Changing phenology of culturally-important shrubs of the Pacific Northwest

Communicating results

• Website: interactive maps with results for the four species, plus bibliographies and information for 20+ additional edible shrub species of the northwest: https://arcg.is/Oj414

• Phenology forecasts for these species for the upcoming year are also available at:phenology.naturecast.org/

• Invasive annual grasses can invade native ecosystems following fires and create invasive-fire feedback loops

• Earlier growth in winter and spring give grasses an advantage over natives

• Can we take advantage of these phenological differences to manage invasions?

Phenology forecasting tools for management and detection of invasive grasses

https://spark.adobe.com/page/5SoUBD5H1uwdn/

Phenology forecasting tools for management and detection of invasive grasses

• Grazing, mowing, or applying herbicides when cheatgrass is active and native plants are dormant can reduce invasions

• However, timing is everything….• Cattle avoid cheatgrass after seeds have formed.

• Can we use past phenology observations to predict the optimal timing for management prior to flowering?

Image credits: Julie Kray

• Phenological predictions can be used to select remote sensing images where differences between invasive grass and native phenology are greatest.

Phenology forecasting tools for management and detection of invasive grasses

West et al. 2017. International Journal of Applied Earth observation and Geoinformation 59 (135-146)

Data Sources: Cheatgrass (Bromus tectorum)

Model fit with limited opportunistic observations: not great…

Preliminary results: Cheatgrass thermal sum models

• Cameras take multiple photos per day

• Pair with ibuttontemperature sensors to get exact dates of flowering and local temperature conditions

• More accurate phenology models?

Data sources: timelapse cameras

• Create fine-scale, short-term forecasts of dates of flowering of cheatgrass

• Freely available online

• Updated daily

Next steps: pheno-forecasts with USA NPN

Next steps: pheno-forecasts with USA NPN

Using plant phenological research to manage ecosystems in an era of global change

• Use phenology models and species distribution maps to help managers address whenand where to focus management efforts

+

Phenology Predictions Potential Species Distribution

https://gis.usgs.gov/inhabit/sandbox.rmd

Excited about phenology?

• Get involved!

• https://www.usanpn.org/

• https://www.inaturalist.org/

• https://www.pnwherbaria.org/

Thanks!