Published on January 5, 2025 in Santa Cruz Sentinel
By Rita Aksenfeld, newsroom@santacruzsentinel.com
You might think watching grass grow is boring, but grasslands have a lot to tell us about climate change. While it might take years for forests to respond to climate change, California’s grasslands are constantly adapting to their new, warmer environment.
The regions across the state where different grasses and wildflowers grow, called the California Floristic Province, host thousands of native and non-native species of plants. The species of grasses found across the California Floristic Province shifted toward those associated with warmer and drier locations over the past 33 years, according to researchers at UC Santa Cruz and the University of Michigan.
When looking at climate change, scientists often need decades of data to see a significant change.
“Everybody had these data sets that they were collecting at their own site,” said co-author Karen Holl, professor of Environmental Studies at UCSC. By putting together measurements from years of unrelated grasslands studies across California, the researchers could see if there were any trends across over a dozen sites.
Grasses that fare better in cooler weather dwindled in numbers over the years, while those that can survive in warm and dry climates persisted.
“It’s not just the direction, but the actual pace of the changes,” Holl said. The different types of grass species changed over time at the same rate as climate change warmed and dried each location.
“When we think about climate change it is no longer just about the temperature,” said lead author Professor Kai Zhu at the University of Michigan. “It actually has an impact in real time in all kinds of ecosystems, grassland being one of the premier ones.”
What surprised him most was “the consistency of the results within the different observational sites.” Unlike most studies that separate the two, the researchers combined results from observations of grasslands and results from changes they made in experimental plots. Sometimes, these two types of studies lead to different conclusions, but in this case, both pointed toward the same thing — cooler weather plants in California’s grasslands are dying out and warmer weather grasses are taking over.
Grassland ecosystems such as wetlands and coastal prairies abound in Santa Cruz, in part due to the work of conservation groups in the area. Preserved areas owned by organizations from UCSC to the Land Trust of Santa Cruz County ensure that these habitats remain free of development. However, invasive species often overrun native plants, complicating conservation efforts.
The Watsonville Wetlands Watch works with local high schools to preserve these ecosystems in current and former agricultural land.
“They’re out removing invasive plants and planting native grasses,” said Jonathan Pilch, executive director of the Watsonville Wetlands Watch. By restoring former agricultural lands using a wide range of native species, they hope to protect these vital ecosystems from the worst effects of climate change.
Other organizations, like the Land Trust of Santa Cruz County, purchase land to be used as nature preserves. The land trust receives state and local funding toward purchasing and preserving local lands, including from the recent county Measure Q, which it supported.
Together, researchers and conservation organizations preserve our grasslands for future generations.
“(We need to) understand what’s happening so that we can guide our restoration and conservation efforts,” said Holl.
