Faculty profile by Gail Kuhnlein
Breaking new ground on pollinator decline and overfishing
September 3, 2019
Fernanda Valdovinos was a curious child in awe of nature, seeking to understand her observations on a level deeper than a mere appreciation of its beauty. She said, “I had weird questions” about the social behaviors of elephants who live in groups contrasted with the behavior of solitary species. “Really fundamental questions.”
Questions Valdovinos asks in her lab today explore important ecological issues such as pollinator declines and fish overexploitation, as well as basic theoretical questions about mutualistic networks, as described later in this article. She joined the University of Michigan’s Department of Ecology and Evolutionary Biology and the Center for the Study of Complex Systems (50/50) in January 2018 as assistant professor. But back to the beginnings first.
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Starting as a young teen, her interests turned to politics because of her passion to change the world. Influence from her aunt, who was a minister of the appellate court in Chile, led to an interest in law before she returned to her earliest love of science, in time to take high school classes to prepare for her current career.
Her political mindset combined with her desire to make a difference, led her to environmental biology. After taking science classes in college, she recalled, “I fell in love with science, especially math and ecology.”
She started working in a lab in her freshman year, the first of three different lab experiences during college. Over her Ph.D. years in Chile, she secured funding for travel including for her first trip to the United States to the University of California, Berkeley, as well as to labs in Europe, to further her research on networks. Her first trip to the U.S. was for an invited oral session at the Ecological Society of America in Austin, Tex., in 2011. Her early notoriety was a result of first authoring a highly cited review in synthesis in Ecology Letters in 2010.
Fast forward to today, Valdovinos’ research asks broad questions about the rules governing ecological interactions. “When you think on a large scale about many species interacting, you need to understand the architecture and the dynamics of their interactions.”
First, in pollination systems, the Valdovinos lab investigates the consequences of the well-known decline of pollinators on ecosystem function in terms of productivity. As we know, pollination puts food on our tables. In fact, pollinators provide an estimated 35 percent of the world’s crop production.
She developed a novel mathematical model that incorporates, for the first time, biological processes such as adaptive foraging and the dynamics of floral rewards and pollination services into the analysis of complex plant-pollinator networks.
Valdovinos is quick to point out that it’s not just the honeybee that is in decline, although it gets the majority of attention. It’s the entire diversity of some 200,000 known pollinators globally, including many bee species and other insects like butterflies, wasps, flies, and vertebrates like hummingbirds and bats. “All provide an ecosystem function. When we only focus on one species, we are missing how complex this system is.”
Further, she studies the architecture of the interactions between a community of plants and their pollinators and how the interactions affect the persistence dynamics of the systems. In other words, why some pollinators don’t go extinct. And if they go extinct, how did it happen?
When a species or a set of species are going extinct, Valdovinos’ research assumes that they are connected to a whole ecosystem. “That ecosystem is an entangled bank, as Darwin says. But it’s not just a messy set of things interacting. We can characterize that entangled bank and can understand, by modeling, its dynamics.”
Rather than considering species as isolated from whole ecosystem, in which tens of thousands of species interact, her research does its best to understand the roles that different pollinators play throughout an ecosystem and the consequences of the interactions in terms of the dynamics, structure and function of these essential systems.
Many times, the honeybee works in detriment to the other pollinators because it’s so efficient in getting resources from the flowers that they compete with native species. This is a prime example of the importance of her work – to disentangle dangers to a certain species or for the whole ecosystem, given their non-random interconnectedness.
Another research area takes the same idea of network structure and dynamics but looks at trophic interactions, or who eats whom, rather than who pollinates whom. She applies food web theory to try to understand the crisis produced by overfishing and to seek sustainable solutions. By combining economic and ecological dynamics, her complex network approach considers the whole ecosystem rather than looking at a target fish separate from its food web, a powerful alternative to previous models.
“We model different economic and ecological scenarios to see which situations are more sustainable.” Sustainability in ecological terms means not too many species go extinct or experience threatening population declines; economic sustainability means profitable fisheries. Once researchers sort out the framework and modeling to answer basic scientific questions then similar models can be used to explore more specific concerns, for example, how climate change affects mutations or invasion patterns.
A third line of research in the Valdovinos lab investigates the evolution of food webs over longer timescales. Using theoretical food web models, she and her collaborators incorporate the effects of evolution (such as mutations and speciations) and population dynamics (such as invasions) into the picture to help determine the relative effects of the various factors.
“The structure and dynamics of the networks we usually study are in ecological time (a time scale that we can directly observe) and many times the structure itself is a snapshot,” Valdovinos explained. The addition of ongoing evolution to the models makes them applicable in evolutionary time (several thousands of years). This gives researchers the ability to analyze how food webs can be assembled, including cascading extinctions and re-assemblies. “The point is to understand how the structure of a system changes.” For example, what explains mass extinctions during a particular era?
Back in the classroom, Valdovinos is co-teaching Population and Community Ecology with Professor Annette Ostling. Valdovinos created a new course called Ecological Networks, cross-listed with complex systems, that she taught for the first time in winter 2019. “There is no other semester-long class like it in the world. There is no textbook on ecological networks,” she said of the relatively new field.
As a member of the Latinx community, she has a strong commitment to supporting diversity, equity and inclusion. “I enthusiastically look forward to further integrating both minority and non-minority cultures into teaching, research and outreach activities,” she said. She’s most passionate about mentorship and community building.
What Valdovinos likes most about her profession is “the intellectual work, when you are challenged by questions that are hard to solve and you keep on going – until all of the sudden you get it. She also enjoys working in teams because of different perceptions and approaches to questions. “You learn a lot by collaborating with your students and with your peers – they really enlarge your view of the world.”
For fun, she and her husband are very committed Argentine tango dancers (not ballroom tango, a sharp distinction that she draws). A track and field athlete as a teenager and a former team soccer player, she said, “I am addicted to the endorphins, so I need to exercise every day, otherwise I get depressed.” She practices yoga, runs, bikes and swims. Clearly, Valdovinos is someone to keep an eye on – if you can keep up!