"It is the challenge of my administration to keep the heart and soul of this city together," Gay said.

But Gay said gentrification poses unique problems in Somerville, which is among the most densely populated cities in New England.

Affordable housing is needed to retain long-term residents, but space issues are making this a difficult task, she said.

"[We] try to create affordable housing wherever we can," Gay said. "Lack of space always gives us problems."

Gay also said that managing growth in East Somerville is a challenge. She pointed to the recent debate over whether IKEA, a furniture store chain, should be allowed to construct a 'big box' type store near the Mystic riverfront as an example of the problem the city faces. The Mystic Task Force, a group advocating pedestrian-minded redevelopment, disapproves of the new construction.

"People wanted that water protected, preserved, accessible," Gay said.

Gay said that although she understands the need to preserve Somerville's urban environment, she is also faced with the city's need for more tax revenue.

She added that negotiations among the Task Force, the city and developers might lead to an acceptable solution.