Rooted to Her Students
Nancy Johnson knows what it is like to be marginalized.
As a student with aspirations for a research career, she was told by a male
advisor that she couldn't have both a career and a family. As a freshly-minted
PhD with two children, she presented revolutionary research about
mycorrhizae—mutually-beneficial associations between a naturally occurring
subsurface fungus and plant roots—to a community of specialists who scorned her
Thirteen years after publishing her controversial—and now
well-accepted—findings, Johnson is in a different position. She is one of the
most widely-respected soil ecologists in the world, as well as the director of
Mentoring in Environmental Biology (UMEB) program at Northern Arizona
University. In that role, she helps students traditionally underrepresented in academia.
"The Undergraduate Mentoring program is all about
trying to increase workforce diversity among environmental biologists,"
says Johnson. "Historically, the field has been pretty monoculture. This
program tries to increase participation among underrepresented populations.
Many Native American and Hispanic students have been UMEB Fellows. Over the
past 10 years, we've supported more than 50 students."
As part of the program, which is funded by the National
Science Foundation, undergraduate students receive up to $12,000 in
scholarships and wages, and have the opportunity to conduct research with
faculty mentors who are experts in their fields. And, according to Johnson, the
relationship between UMEB Fellows and their faculty mentors is win-win: students
gain valuable research experience, professors gain a research assistant, and in
the process, the field of environmental biology is advanced.
"We try hard to place the students in laboratories
with professors who are studying what they're interested in," she says.
"We don't tell the students what they have to study, we ask them, 'What do
you want to study?' because the whole idea is to give these talented students
an opportunity to delve deeper into an area that they really like. Hopefully,
they'll excel at it and then want to go on to graduate school."
According to Johnson, the program is beginning to
positively impact the effort to bring greater diversity to the scientific
academy. Several students from the initial cohort have gone on to earn advanced
degrees, and Northern Arizona University undergraduate students continue to use
the program to explore areas related to chemistry, biology, forestry, botany
ecology and agriculture
Johnson is just as committed to making a difference in
her role as a soil ecologist. Currently, her inquiries into mycorrhizae have
the potential to help researchers understand some key components related to
global warming. Right now, says Johnson, no one is certain how much carbon that
soil beneath grasslands can sequester in complex organic compounds. If we could
better understand carbon dynamics in soil, she says, we could more accurately
predict how agricultural practices, for instance, affect global carbon dioxide
"One of the big places where carbon gets stored is
below ground, in the soil," says Johnson. "Because mycorrhizae are so
abundant, they are probably a pretty important carbon sink. But we don't really
understand the factors that control how much gets stored down there. In some
situations, soils can be a source, especially in agricultural systems. But when
agricultural systems are abandoned and turn back to forests they can tie up a
lot of carbon. But not much is known about the effects of grassland management
on soil carbon dynamics."
Johnson is also adamant about protecting ecosystems from
unnecessary risks. For example, millions of dollars worth of mycorrhizal fungal
inoculations are sold each year as part of agricultural, horticultural, and
ecological management programs. According to Johnson, no one knows whether
these massive efforts are helping or harming the environment.
"I'm convinced that most commercial mycorrhizal
inoculum is snake oil," she says. "Marketers are convincing the
public that unless you buy their product and put it in your soil then you won't
have mycorrhizae and your plants won't do well. But mycorrhizae are there
anyway [they are naturally occurring]. Rather than introducing non-local
mycorrhizal fungi, we should simply manage the existing mycorrhizal symbioses
to maximize their benefits. This approach saves money and avoids the potential
risks associated with introduction of non-native species."
As her work continues, Johnson hopes to keep exploring
the unknown. She recently spent a month in Africa’s Serengeti region to better
understand mycorrhizal structure and function across natural soil fertility and
precipitation gradients. As a mentor to undergraduate students—both in the
classroom and as director of the UMEB program—she will continue to reinforce that
sense of exploration.