Associate Professor of Environmental Studies Kai Zhu recently won $732,127 in funding through a five-year grant from the National Science Foundation (NSF) Faculty Early Career Development Program (CAREER). Zhu applied for the award last year as a pre-tenure faculty member. The funding will support research to model global interconnections between climate change and plant phenology.

As climate change raises global average temperatures, phenology—the study of seasonal life processes—shows that many plants are responding by shifting the timing of temperature-dependent life events, like flowering and the growth of new leaves. But these changes in phenology can, in turn, affect the rate of climate change by altering the role plants play in important climate system processes, like carbon uptake. The new research will aim to quantify global changes in plant phenology in ways that predict and incorporate the complexity of climate feedback loops.  

“The basic idea of the project is to view climate change and phenology as an integrated system, with influences from both directions,” Zhu said.  

To accomplish this, Zhu and his research team will need to combine traditional ecology methods with data science tools. They’ll incorporate everything from individual observations of plants and flowers to findings from formalized regional experiments and satellite remote-sensing data in order to form a clearer picture of the interconnections between climate change and phenology. 

“What we are doing is scaling up ecology research on this topic to show how what you’re finding in one place may also apply to other places or may affect what happens in other places,” Zhu explained. “And we’re injecting modern, state-of-the-art artificial intelligence and machine learning tools to help address these complex ecological questions.”

The findings from this research could have several important applications. A better understanding of climate change impacts on plant phenology can inform agricultural management to maximize crop yields. And more accurate forecasting of regional pollen counts could help allergy sufferers navigate longer pollen seasons and increasing pollen loads. Phenological changes also offer a unique opportunity for climate change education, which is another goal of the project. 

“When we talk to the public about climate change, the changes in temperature that we’re seeing are hardly detectable by normal people, but what we can easily see is that a lot of things are happening in biological systems as a result,” Zhu said. “Flowering is getting earlier, growing seasons are getting longer; we can use people’s own observations of phenology to raise awareness that this is attributed to climate change.”

With support from the UC Santa Cruz Building Belonging program, Zhu has already been working with environmental studies graduate student Yiluan Song and undergraduates Caitlin Schilt, Jade Guzman, and Luke Hamilton to study how people use social media to observe phenology. Now, the new NSF funding will allow the team to build a series of websites and apps that will integrate citizen science and social media to provide hands-on climate education related to plant phenology. 

“We see phenology observations as a new opportunity to make people more aware of climate change, and we can allow people to generate phenological knowledge instead of just receiving it,” said Yiluan Song. “We also want to make daily delivery of pollen forecasting information to people who are potentially suffering from pollen allergies, and this can help people understand the link from public health to phenology and then to climate change.”

The NSF grant will also support the development of graduate-level data science classes in Geographic Information Systems (GIS) at UC Santa Cruz. And a partnership with local high schools will offer students guided “phenology walks” through the UCSC Arboretum & Botanic Garden to learn more about climate change by collecting citizen science data. Zhu said he has been particularly excited that his NSF CAREER Award will allow him to combine these elements with the opportunity to generate new research findings.

“It’s not only pure scientific research, in the traditional sense, but also outreach and education to university students, other students, and the public,” he said. “I think it’s going to be a lot of fun.”