Dr. Jennifer Ison

Dr. Jennifer Ison

Dr. Jennifer Ison in the prairie at the Chicago Botanic Garden

Jennifer Ison grew up in central Illinois where corn and soybeans fields stretch for miles in every direction. While some may not consider this the most picturesque landscape, she fell in love with the local wildflowers at a restored prairie near her childhood home. Jennifer would walk through this restoration at least once a week and loved seeing the flowering plants change as the season progressed. In particular, prairies have dramatic color shifts throughout the summer, such that there are waves of purple, white, pink, or yellow flowers. Jennifer is still early in her career having received a PhD just two years ago. She earned her undergraduate degree from St. Olaf College in Northfield Minnesota and subsequently started working at the Chicago Botanic Garden while pursuing her doctorate. She is now a postdoctoral researcher at the University of Toronto.

During her graduate studies, Jennifer began thinking about how flowering time affects pollen movement between individual plants. Over 60% of flowering plants require pollen from another plant to produce seed. The distance between two plants has been shown to predict pollen movement (pollen moves more between plants that are closer). However, the synchrony (or overlap) in flowering should also affect pollen movement between plants, and Jennifer is studying how flowering synchrony predicts pollen movement and the interaction with distance between plants.

For the past 8 seasons, she has collaborated with Stuart Wagenius of the Chicago Botanic Garden to monitor the daily flowering phenology of an iconic prairie flower, the purple coneflower (Echinacea angustifolia). They are beginning to see how flowering varies between years and the effects of mild winters or dry early springs on flowering time. Studies have shown an advancement of flowering onset in spring wildflowers; however, Jennifer is trying to better understand how climate change might be affecting a mid-summer flowering species, like purple coneflower. Prairie plants are also unusual in that flowering is often induced by fire. A season with a prairie fire has significantly more plants in flower, and those plants flower more synchronously (at the same time). Today, many managed prairies have prescribed burns (controlled fires set by site managers). However, many prairies especially small remnant ones, do not burn regularly. Jennifer believes that it is important to study how both a lack of fire and climate change are affecting flowering phenologies of prairie plants.

For Jennifer, photoperiod (day length) has always signaled seasonal changes. She jokes that like many plants, she is sensitive to photoperiod, stating that "my favorite time of year is when the days start to shorten and you know autumn is around the corner, with its beautiful fall colors and amazing food." She encourages everyone to start tracking phenology in their own backyard and points out that phenology is not just flowering time; it's also timing of seed production or when leaves change color, and all of these can be tracked.