Rafa Tasnim: Safeguarding Maine wild blueberries from climate change 

Like many crops across the world, wild blueberries face several threats posed by climate change, including rising temperatures. Rafa Tasnim from Dhaka, Bangladesh, is trying to pinpoint new ways growers can protect one of Maine’s most iconic crops by using resources from the state’s backyard. 

Since joining the University of Maine in 2019, Tasnim, a Ph.D. candidate in ecology and environmental sciences, has led studies that revealed that wild blueberry fields in Down East Maine are warming faster than the state as a whole, and that fields experience warming differently, depending on their location, the season and the time of day, among other factors. Her work has garnered state and national media attention. 

These studies, however, are only the beginning of what Tasnim hopes to accomplish while at UMaine. Another recent study that Tasnim co-authored found that wild blueberries are more sensitive to dry conditions over a long period of time, meaning proper soil moisture management is more essential than previously expected. Tasnim is evaluating materials that may improve water retention in the soil that would protect the plants during dry periods at blueberry fields, particularly those once considered waste products like compost and biochar to help create more sustainable food systems. She also has been assessing soil amendments, foliar fertilizers — those applied directly to leaves, and nanocellulose.    

“I’m trying to study materials that are available here,” she says. “My idea is to use whatever recyclable waste we have around us so that we don’t pressurize the landfills anymore.” 

Tasnim conducts her research in the lab of YongJiang Zhang, her adviser and an assistant professor of applied plant physiology, and at UMaine’s Blueberry Hill Farm in Jonesboro. The equipment she uses includes remote sensing tools and ArcGIS software, portable leaf photosynthesis measurement system, leaf chlorophyll content meter, leaf area meter, soil moisture meter, real time soil water stress monitoring sensors and pressure chamber that can measure plant water stress and other plant attributes. 

Ecology and environmental sciences was not always Tasnim’s field of study. She began her academic career in civil engineering, earning her bachelor’s from the Military Institute of Science and Technology (MIST) in her hometown and a master’s degree from the Hong Kong University of Science and Technology (HKUST), with a specialization in geo-environmental engineering. 

Her passion for safeguarding food systems from a warming planet ignited while she was working on a slope stability project during her postgraduate studies in Hong Kong. In particular, she was investigating the effects of increased carbon dioxide levels on vegetation that grows along slopes, which helps stabilize them by removing excess moisture through transpiration. Tasnim found that rising carbon dioxide levels reduce transpiration of those plants, which she says can lead to more water pressure in those slopes during rainfall further decreasing soil stability and put slopes at greater risk of landslides.  

While conducting her project, Tasnim says she realized she enjoyed researching plants, and how greenhouse gasses and climate affect the plant-soil interaction more than traditional civil engineering research areas, and she resolved to shift gears and pursue a new field. 

“That’s how things changed for me,” she says. “That was the time in my master’s program that really sparked and helped me to understand what I really wanted.” 

While studying at UMaine, Tasnim has mentored undergraduate students for their own research projects, taught courses, presented and judged at the 2019 and 2021 UMaine Student Symposium, presented her research at the 12th International Vaccinium Symposium last year, and served as a technical reviewer for multiple journals. 

She also has earned several fellowships, grants and other awards from the university and outside organizations, all of which have fully funded her studies. This year, she received the Doctoral Student Graduate Research Excellence Award from the College of Natural Sciences, Forestry, and Agriculture; the Janet Waldron Doctoral Research Fellowship from the Graduate School; and the BioME Seed Grant from the Bioscience Association of Maine. 

Tasnim was still searching for Ph.D. programs when she moved to Maine with her husband, SK Belal Hossen, so he could pursue his doctoral degree in geotechnical engineering at UMaine. She became interested in the university’s program offerings after seeing the research conducted in the greenhouses on campus. Meeting with Zhang, learning about his research and witnessing the top-of-the-line tools in his lab, however, sealed the deal, Tasnim says. 

Zhang has provided guidance on which courses would help her to execute her research and connected her with other experts like Lily Calderwood, wild blueberry specialist of UMaine Extension and assistant professor of horticulture, and Francis Drummond, professor emeritus of insect ecology and pest management.

“He is the best,” Tasnim says about Zhang. “Without my adviser’s guidance and directions — he actually showed me how to move forward with this kind of research — nothing would have been possible.” 

While Tasnim’s studies have been significant and garnered widespread acclaim, she says they mean little unless growers apply her findings to their management strategies. That is why she relies on and greatly admires the professionals at UMaine Extension, who make her research and others more accessible to producers and the general public.  

UMaine Extension experts like Calderwood facilitate access to complex academic research conducted in the university by creating annual reports that compile researchers’ findings, and host conferences and field days where growers can literally meet and discuss the research findings with UMaine faculty and researchers. Tasnim has been assisting Calderwood and others in drafting the reports for the blueberry growers since joining UMaine in 2019. 

“That’s the thing I feel good about, is that my publications are not just some papers that are published and cited. They are actually getting to actual audiences: the growers from Maine and potentially growers from other states, other regions too,” Tasnim says. “If (my work) is not going to help anybody change anything, then it doesn’t matter how many publications I have or how many citations that I get.”  

Tasnim plans to graduate from UMaine in fall 2023. After receiving her doctoral degree, she hopes to continue helping growers, conducting soil and plant science research under changing climate and supporting more sustainable food systems by working as a faculty researcher, an employee of a federal agency or in research and development. 

“Whether you believe it or not, climate change is happening. Food insecurity is happening. Agricultural crop systems are devastated in different regions of the world,” Tasnim says. “I really want my research to have implications on the real world, even if it’s a tiny bit, in terms of crop systems and food insecurity problems.” 

Contact: Marcus Wolf, 207.581.3721; marcus.wolf@maine.edu