Sustainable LA Grand Challenge Research Spotlight: Joscha Beninde

September 18, 2019

Interview by Chloe Zilliac

UCLA postdoctoral researcher Joscha Beninde crouches among the tall grasses on Sage Hill Park on the UCLA campus, fishing pole in hand.

On lucky mornings, he spots the right lizard species — a western fence lizard, side-blotched lizard, or alligator lizard — right away. Keeping his hands steady, he casts a line with a small noose attached out into the grasses, slipping it gently over the lizard’s head. On unlucky mornings, however, he spends hours waiting for the right lizard to scamper by, only to leave empty-handed.

UCLA postdoctoral researcher Joscha Beninde

Beninde uses the study of landscape genetics to help plant and animal species survive and persist in Los Angeles. His research focuses on how the city’s built infrastructure— the concrete freeways, high rise buildings and urban sprawl — affect the health of several spider, butterfly, lizard and plant species.

“Knowing that these species are around now is cool, but will they still be around in 20 years, 30 years, 50 years from now?” Beninde said. “For that we need to know a little bit more about their genetics.”

How Genetics May Hold the Key to Species Survival

In order to understand the effects of city infrastructure on biodiversity, Beninde looks at the genetic relatedness of individuals and populations within the same species across different areas of the city. For example, he may compare DNA collected from lizard populations living on opposite sides of a freeway. If genes from the two populations are not closely related, it indicates that the freeway is preventing gene flow.

Gene flow, or the transfer of genetic diversity across populations, increases genetic diversity within species. Genetic diversity can help populations survive and adapt to changes in their environment, including threats posed by new diseases and climate change. Thus, a freeway that inhibits gene flow limits genetic diversity and makes the lizard species more vulnerable.

In order to identify broad genetic trends, Beninde must examine a huge number of plant and animal species from around Los Angeles — a collection of more than 4,000 samples to date. Partners like the National Park Service, the U.S. Geological Survey and the Natural History Museum of Los Angeles County have all contributed to his collection, but he has also spent many days in places like Laguna Beach, Malibu State Beach, and Compton, collecting samples himself.

Beninde’s research in L.A. builds on his work as a doctoral student in Germany, where he studied how urban infrastructure affects gene flow within a lizard species. The results of that analysis were surprising. Beninde expected to find that the city’s infrastructure significantly affected gene flow between lizard populations. Instead, he found that natural barriers—like rivers—are more significant. The results indicate that while human caused changes to environments are important, natural factors cannot be overlooked. 

Side-blotched lizard
A Voice for a More “Holistic” Approach to Conservation

The results of landscape genetic research projects like Beninde’s will be important for protecting L.A. biodiversity as the climate changes and the region grows. L.A. is home to more than 4,000 unique native plant and animal species, qualifying the region as one of California’s many biodiversity hotspots. Conservation policies implemented in L.A. can serve as a model for cities worldwide.

Landscape genetic research can help scientists understand when conservation efforts are needed to protect a species, and which species are likely to be vulnerable to climate change.  Beninde’s project, funded by UCLA’s Sustainable LA Grand Challenge and the German Science Foundation, is one of several species management projects on the UCLA campus.

As a voice in the conservation movement, Beninde said he hopes he can act as an advocate for a more holistic approach to conservation – one that takes into consideration a diverse set of interests, including development.

“Conservation efforts that don’t take into account how the work will affect the surrounding communities are less likely to succeed,” Beninde said. “I see myself as someone who can speak for nature and biodiversity, and help to translate those needs in an urban environment.”