California's public schools may be facing unprecedented levels of pressure as they try to teach an increasing number of children in poverty with fewer employees and a continual threat of cutbacks, a report by the Mountain View-based research group EdSource found.

Through publicly available data and surveys of the state's 30 largest districts -- including San Francisco, Oakland, Mt. Diablo, Fremont, San Jose and San Francisco -- policy analysts compiled information on a number of "stress factors," from local unemployment rates to smaller budgets as a result of the state's budget deficit. In 2010-11, California's public schools spent $2,856 less on each student than the national average, according to the California Budget Project.

The report showed the percentage of Oakland children living below the poverty level rose by 8 percentage points between 2007 and 2010, to 33 percent. Even in the more economically stable city of Fremont, the child poverty rate more than doubled during that time, to 9 percent, based on estimates from the U.S. Census Bureau's American Community Survey.

"All of this puts enormous stress on children and has an impact on how they do in school," said Louis Freedberg, a former San Francisco Chronicle and California Watch journalist who is now the director of EdSource. "Schools, then, have to work harder to get these kids to succeed, with less resources."

The report was published with voters in mind. In November, two education-related tax measures that would raise billions of dollars for public education may appear on the ballot: Gov. Jerry Brown's tax plan and another proposal by civil rights attorney Molly Munger. If the measures don't pass, schools face the prospect of losing $2.8 billion in K-12 general-purpose funding, midyear.

"Voters will have to decide, 'Do schools need more funding?' " Freedberg said. "We wanted to put this information out so Californians who may not be involved in schools directly can get a clearer picture of how schools are doing."

This report comes on the heels of an annual survey of hundreds of school districts by the Legislative Analyst's Office, which advises lawmakers on state policy. That report found that between 2007 and 2010, California schools reduced the teacher workforce by 11 percent, support staff by 14 percent and administration by 16 percent.

"There's just this constant level of stress. Just the littlest thing will rock your budget," said Carmelita Reyes, principal of Oakland International High School in North Oakland.

Reyes, whose 330-student school can't afford a counselor or an assistant principal, said she broke down Friday after learning that her school didn't receive a large grant that would have funded tutoring and mental health services for her immigrant and refugee students.

This weekend, Reyes' husband and some of her teachers will be among a group of 150 cyclists -- ranging in age from 10 to 75 -- to ride all or part of the way from Oakland to Sacramento to raise money for their schools and lobby for improved educational funding. Reyes will be trailing the riders in a support vehicle; she said she hoped the buzz from the "Ride for a Reason" event will make more Californians aware of the realities facing public schools.

"I feel like the sacrifices are unacceptable in terms of what we're asking kids to do without," she said.

Read Katy Murphy's Oakland schools blog at www.IBAbuzz.com/education. Follow her at Twitter.com/katymurphy.

report: "Schools under stress"
The full EdSource report can be found at: http://www.edsource.org/pub12-schools-under-stress.html