San Marcos,
08:07 AM

Burned Hillside Becomes Learning Laboratory

By Christine Vaughan

The contrast of blackened soil and burnt shrubs adjacent to young, brightly green plants was striking as biology students hiked the south hillsides of campus where 18-months ago the Cocos Fires raged dangerously close to CSUSM, resulting in the evacuation and closure of campus in May 2014.

Led by Professor George Vourlitis, the excursion allowed biology undergraduates to test their newly acquired ecological skills by examining plant abundance and regrowth following the wildfire.

Working in teams, students cataloged plant species, measured growth and noted the geographical position of plant life within several two-meter radius plots. The field assignment is part of the upper-division course, Biology 354: Principles in Ecology, which introduces biology majors to concepts and methods used to assess and quantify ecological processes.

Fire is part of the natural ecosystem for southern California’s chaparral – a plant community characterized by drought-hardy, woody shrubs in a Mediterranean-type climate with mild winters and dry, hot summers. Chaparral covers more than a million acres throughout San Diego County, including the undeveloped land on, and surrounding, CSUSM.

More than 24 species of plants populate the CSUSM hillside. Restoration of the chaparral following a wildfire is a long process that can span over several decades, although most of the initial plant regrowth will occur in the first 10 years.

Students compared fire-affected areas that were hydroseeded – a planting process that uses a blend of water, seed and mulch to stimulate plant growth – to areas that were growth was occurring naturally.

Students noted the difference between the regrowth of north-facing slopes versus south-facing slopes. In the Northern Hemisphere, south-facing hillsides get more direct sunlight and as a result are hotter and drier, and have less biodiversity, than north-facing slopes.

"Studying how ecosystems respond to disturbances happens best through the hands-on field experience," said Vourlitis. "Exploiting chance events, such as the Cocos Fire, provides an opportunity for illustrating ecological concepts and techniques in a system and environment that are relevant to students and allows open-ended laboratory activities that are more closely aligned with scientific research."

In addition to using the hillside as a learning laboratory, Dr. Vourlitis and a team of research students are piloting several studies that focus on the regrowth and ecosystem dynamics of CSUSM’s outlining chaparral.