![]() ![]() When the Spanish colonized California, they brought forage grasses like wild oats that they thought would benefit cattle. Secondly, sheep eat non-native grasses that generate growth-suppressing debris and compete with purple needlegrass for resources. It’s hard for a little seed to get enough light through all of that,” Larios said. “Sometimes you get litter that’s as deep as a pencil - so much dead, non-native grass piles up. One, by trampling on leaf litter and other organic debris, sheep created space for new needlegrass to grow. Though drought was not beneficial for any of the plants in this study, the researchers believe grazing helped needlegrass survive in at least two ways. As far back as the 1800s, some researchers hypothesized that the combination of grazing and drought resulted in the loss of perennial grasses. Some conservationists believe sheep eating the target grass, particularly during already stressful drought years, does not enhance their survival. Grazing is a controversial strategy for grassland restoration. The researchers would like to learn whether the two sites that remained healthy have needlegrasses that are genetically distinct. When sheep were removed from the study sites, the needlegrass in all but two of the sites became less healthy. Measuring the size of an individual grass clump to assess its health. “Perhaps counterintuitively, we saw that the needlegrass generally died back when sheep weren’t allowed to graze on it.” “By tracking each plant over time, rather than scanning broadly across an area, we gained much more clarity about how the grass responds to the grazing,” Larios explained. However, the district’s method of applying a strategy like grazing, and then measuring the percentage of needlegrass clumps in a given area resulted in data that didn’t follow a discernable pattern from year to year. Previously, the park district spent a decade trying to assess the success of its grassland maintenance techniques. The positive effects of the grazing were amplified in times of wetter weather. Their findings, now published in the Journal of Applied Ecology, were that purple needlegrass did better in places where sheep were allowed to graze. They placed small bags over many of the grass clumps to capture the seeds and quantify the number of seeds they produced. The researchers took measurements of plant health including growth and seed production. Plant ecologists Loralee Larios, UCR, and Lauren Hallett, University of Oregon, monitoring purple needlegrass in Northern California. They tracked the health of nearly 5,000 individual needlegrass clumps over six years, including an El Niño rain year as well as historic drought. To meet that challenge, Larios teamed up with University of Oregon plant ecologist Lauren Hallett and Northern California’s East Bay Regional Park District. “However, identifying successful management strategies for a species that can live for a couple hundred years is challenging.” “Where it grows, these tall, slender bunches become focal points, beautiful as well as environmentally beneficial,” said Loralee Larios, UC Riverside plant ecologist. For these and other reasons, many who work toward habitat restoration hope to preserve the needlegrass. It is drought resistant, promotes the health of native wildflowers by attracting beneficial root fungi, burns more slowly than non-native grasses and speeds the postfire recovery of burned lands. Today, California has lost most of its grasslands, and the needlegrass occupies only one tenth of what remains. Purple needlegrass once dominated the state’s grasslands, serving as food for Native Americans and for more than 330 terrestrial creatures. ![]()
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