ROME — It used to be that some residents of Trastevere, a traditional working-class neighborhood on the west bank of the Tiber River, would boast they had never crossed the river into central Rome. What for, after all? The tightknit community had everything it needed - a butcher, a baker, artisans, and, on the central square, a large vegetable market for fresh artichokes, Parmesan cheese, and garlic. It had been that way for centuries.
These days, however, Trastevere is changing. The area's new residents - young professionals, students, and, increasingly, American expatriates - go to the cocktail bar instead of the butcher and to fashion boutiques rather than bakeries. They not only scooter across the Tiber, but also jet across the Atlantic.
And the market in Trastevere, like many of the traditional open-air markets that define urban life in Rome, is threatening to disappear.
"The longer I had my vegetable stand, the worse business got," says Armanda Panichi, who recently gave up her stall and retired. "I get much more money from my pension than I was earning toward the end. You just can't survive on the couple of apples the tourists buy."
The changes Ms. Panichi succumbed to are affecting many neighborhoods in Rome, and larger cities across both Italy and Europe. Call it a collision of lifestyles or expectations: Young professionals, who are moving into the area enjoy the quaintness of the outdoor markets, but don't patronize them. They want a modern lifestyle, which includes large supermarkets.
As a result, centrally located neighborhoods are becoming more and more trendy and - in cities like London, Paris, and Berlin, as well as Rome - are getting expensive. So far, the development is one that many European cities are encouraging, says Rowland Atkinson, a gentrification expert from the University of Glasgow.
"In North America," he says, "the word gentrification has very much a negative connotation - people immediately think of the social dislocation that often goes along with the process. In Europe, that negative connotation isn't really there yet. In England, at least, it is seen as a very positive development, as a way to combat inner city blight."
The trick, of course, is to improve the city center without sacrificing those elements that make life there unique.
In Rome, many people feel the scale is tipping in the wrong direction. Rents in the central neighborhoods are rising 9.2 percent per year - the fourth fastest growth rate in the world, according to the international real estate firm Cushman and Wakefield. Even in outlying districts of Rome, rents are climbing at a 5.3 percent clip.
It's not just the cost of living that is changing. Rome, in contrast to most of its post-World War II history when Italians were leaving to work elsewhere, is becoming a city of immigrants. More than 17 percent of the 80,000 city-center residents are foreigners, and the area around the main train station is quickly developing into a Chinatown.
The percentage of foreigners in sought-after neighborhoods like Trastevere is even higher - and they tend to be richer. Two private universities in Trastevere, John Cabot University and the American University, have brought a number of American students and professors into the area. The neighborhood has also proven popular among the increasing numbers of young European professionals moving to Rome. With them have come cocktail bars, pizzerias, cafes, and stylish shops. On weekend evenings, the narrow, cobblestone streets of Trastevere are jammed with young partiers enjoying the old-city atmosphere.
Yet what they are looking for is quickly disappearing, says Bjorn Thomassen, a professor of anthropology at the American University who is planning to teach a course next term on Rome's gentrification.
"It is a bit ironic," he says, "that Trastevere is sort of the heart of Rome, and many people, Romans included, talk about it being the real Rome. But there aren't too many Romans there anymore. They are all moving out."
And they are taking their traditions with them.
For centuries, Romans have made daily market visits to pick over the colorful bounty of fruits, vegetables, and cheeses piled up on the wooden tables under broad sun umbrellas. All over Italy, outdoor markets remain an important nexus for villages, towns, and cities - and markets in central locations such as Campo di Fiori near the Pantheon are major tourist attractions.
A photo of an elderly Roman woman buying artichokes is a must for any Italian vacation album, yet those photos are harder and harder to find, however, and market vendors can no longer rely on a steady stream of Roman housewives. Those who have moved into central Rome are more likely to shop after working hours at the growing number of supermarkets that dot central Rome than at the open-air markets.
"We are surrounded by supermarkets," says the former vendor Ms. Panichi, who has already moved away from Trastevere to save on rent. "We smaller vendors don't have a chance anymore. We are being chased out."
Help may be on the way, according to Giovanni Pineschi, an urban planner working on an independent evaluation of Rome's transportation network. After decades of allowing more or less uncontrolled growth with no effort to retain traditional shops and lifestyles, the Roman government is now pursuing a "master plan" aimed at preserving the character of central neighborhoods. But, he says, there probably won't be assistance available to older residents of neighborhoods like Trastevere.
"A lot of the housing in central Rome," he says, "is controlled by large corporations who tend to push the rents up. They have a tremendously strong lobby, and the city is not likely to take them on."
For the Trastevere market vendors, about all they can hope for is that their new neighbors get used to shopping out of doors. Bruno Valentini, a fruit-stall operator who lives on the outskirts of Rome, is hoping that the city pays for refurbishing the market's rundown sales booths, or replaces them entirely.
"We definitely need help to compete," says Mr. Valentini. "We could really attract more customers if our stalls looked nice and were more traditional. But the city doesn't seem to care."