SANTA MONICA, Calif. — Fresh blotches of graffiti decorate the backs of street signs here near the ocean.

Tags have popped up on guardrails along the dirt trails near Griffith Park across town.

There are, almost daily, fresh splashes on walls in the San Fernando Valley, on downtown Los Angeles buildings and on billboards along the highways.

And Los Angeles does not appear to be alone in grappling with a recent upsurge in graffiti, which is turning up in some unlikely places. A bumper crop of scrawls is blossoming in many modest-size communities across the country — in places like Florence, Ala.; Bernalillo County, N.M.; Taylors, S.C.; and in larger cities like Nashville, Tenn.; and Portland — even as major cities like Chicago, Denver, New York and Seattle say vigilant anti-graffiti campaigns have spared them thus far.

The upturn has prompted concern among city officials and renewed a debate about whether glorifying such displays — be it in museum exhibits, tattoos or television advertisements — contributes to urban blight and economic decay. But it is also stirring a debate about what is causing this recent surge and whether it might be an early indicator that anxiety and alienation are growing in some struggling urban areas in the face of stubborn unemployment and the lingering effects of the recession.

In Portland, officials said taggers from other communities were defacing their property. “We’re arresting more people from out of town,” said Marcia Dennis, the city’s graffiti abatement coordinator. “For every one we get cleaned up, something else takes its place.”

The latest statistics from Los Angeles, where the unemployment rate was 11 percent in May, attest to a widening problem: The city removed 35.4 million square feet of graffiti for the fiscal year that ended June 30, an 8.2 percent jump over last year, officials said.

“We’ve seen the amount of graffiti go up yearly,” said Paul Racs, director of the Office of Community Beautification.

The upsurge comes as communities like Los Angeles, struggling with budget cuts, have trimmed graffiti fighting programs; the $7.1 million budget for graffiti eradication last year was cut 6.5 percent in the budget that took effect July 1.

Some officials say it is a symptom of summer recess, a tough economy that has left many teenagers out of work and a general sense of anxiety and malaise.

Neighborhood leaders and law enforcement officials also blamed what they call a glamorization of graffiti, reflected by a new graffiti exhibit at the Sunset Marquis Hotel in West Hollywood, even after an earlier furor over a full-fledged graffiti exhibit at the Museum of Contemporary Art.

“It’s because of the pop culture,” said Ramona Findley, a Los Angeles police detective who heads the department’s graffiti task force. “It’s very interesting; with your violent crime going down, it seems like your mischievous crime is going up. The art world has accepted it. People make money from graffiti T-shirts. I was in Walmart on Easter, and I saw graffiti Easter eggs.”

Dennis, in Portland, described graffiti as “addictive behavior,” adding: “The rush is addictive, and these guys don’t quit. They all think they’re going to end up being fabulously wealthy graffiti artists like Marc Ecko or Banksy or Shepard Fairey.”