Once thought resistant to invasion, regional deserts are losing native plants to aggressive weedy species like Saharan mustard.
Once thought resistant to invasion, regional deserts are losing native plants to aggressive weedy species like Saharan mustard. New research shows its spread is disrupting biodiversity and reducing the desert’s ability to recover from extreme climate swings.
The UC Riverside study published in the journal Ecology analyzes 17 years of data from the university’s Palm Desert campus and surrounding desert regions. UCR ecologist Loralee Larios and her colleagues found that Saharan mustard threatens native plants by overwhelming the desert’s natural seed bank.
The seed bank—a reservoir of dormant seeds that resides in the top five centimeters of the soil—acts as a buffer against extreme weather by allowing plants to germinate at an optimal time and pace. Many native species rely on this system to survive long dry spells.
“It is like a literal bank account for a rainy day. When conditions are right, these seeds sprout,” said paper first author Clarissa Rodriguez, former graduate student in the Larios laboratory and current Natural Reserve System manager at UC San Diego.
Read more at University of California - Riverside
