Crippling drought in California has reduced the number of native wildflowers in the state’s grassland, potentially foreshadowing how climate change may affect plant life worldwide in the coming decades, according to new research in the journalProceedings of the National Academy of Science (PNAS).
The impact of wildflower loss may be minimal at first, but researchers say effects could spread up the food chain, eliminating a key food source of insects and pollinators and subsequently hurting small animals. As the habitat changes, it will become more vulnerable to incursions from invasive species.
The researchers evaluated nearly 15 years of data on California plant diversity for the study. Although plant diversity may change over time for a number of reasons, scientists were able to rule out a number of other factors as the cause of decline in this case, including problems related to grazing, fires and the prevalence of invasive grasses.
“Fifteen years of warmer and drier winters are creating a direct loss of native wildflowers in some of California’s grasslands,” said lead author Susan Harrison, a professor at the University of California Davis, in a press release. “Such diversity losses may foreshadow larger-scale extinctions, especially in regions that are becoming increasingly dry.”
Indeed, California is not the only place to show the first signs of plant species loss. Species diversity on European mountaintops has declined in recent years as the climate dries, according to the study. And, if climate change continue on the same trajectory, the study suggests we should expect the same elsewhere soon.
See How California Is Using Its Diminishing Water Resources
The Los Angeles Aqueduct Cascades, which bring water 223 miles from the Owens River in the eastern Sierra Nevada mountains, and 137 miles from the Haiwee Reservoir, are a major source of water for Los Angeles. Seen here in Sylmar, Calif. on May 4, 2015. Lucy Nicholson—ReutersThe Los Angeles Aqueduct Cascades are seen in Sylmar, Calif. on May 4, 2015. California's snowpack, which generally provides about a third of the state's water, is at its lowest level on record. Lucy Nicholson—ReutersWith the country's most populous state entering the fourth year of a devastating drought, Governor Jerry Brown has ordered an overall 25 percent cut in urban water use though the first statewide mandatory reductions in California's history. The suppliers with the highest per capita water use would have to accept a 36 percent cut. Lucy Nicholson—ReutersA tractor ploughs a field next to a canal in Los Banos, Calif. on May 5, 2015. California water regulators on Tuesday adopted the state's first rules for mandatory cutbacks in urban water use as the region's catastrophic drought enters its fourth year. However, the state's massive agricultural sector, which the Public Policy Institute of California says uses 80 percent of human-related consumption, has been exempted from cutbacks.Lucy Nicholson—ReutersA worker walks through farm fields in Los Banos, Calif. on May 5, 2015. Urban users will be hardest hit, even though they account for only 20 percent of state water consumption.Lucy Nicholson—ReutersApproximately 9 million acres of farmland in California are irrigated, representing roughly 80% of all human water use. But, farm production and food processing only generate about 2% of California’s gross state product, down from about 5% in the early 1960s.Lucy Nicholson—Reuters"In the Central Valley, where most agricultural water use occurs, the failure to manage groundwater sustainably limits its availability as a drought reserve. The increase in perennial crops—which need to be watered every year—has made the region even more vulnerable," the Public Policy Institute of California states. Lucy Nicholson—ReutersCentral Valley farmers have witnessed land sinking by as much as 3 feet, San Francisco Gate reports, as water agencies tap underground reservoirs at unprecedented depths. Water pours into a canal in Los Banos, Calif., May 5, 2015. Lucy Nicholson—ReutersLivestock products, including meat, dairy and eggs, account for more than a quarter of California's agricultural sector, a $12.5 billion industry, according to the USDA. Cattle are among the most water-hungry livestock, consuming an average of106 gallons per pound of beef. Cattle are seen at Harris Ranch in Coalinga, Calif. on May 5, 2015. Lucy Nicholson—ReutersCalifornia's planting of staple crops such as cotton, corn, oats, barley, wheat, rice, and sunflowers will total 1.72 million acres in 2015, down from 1.90 million acres in 2014, according to data from the National Drought Mitigation Center. A wheat field is seen in Los Banos, Calif. May 5, 2015. Lucy Nicholson—ReutersA water protest sign is seen in Los Banos, California, United States May 5, 2015. Central Valley counties suffer some of the highest unemployment rates in the state, topping out at more than 20% in Colusa County, according to the state's Legislative Analyst's Office.Lucy Nicholson—Reuters
