Harvard University president Drew G. Faust spent her first workday in power yesterday hosting an ice cream social and doing business in a new office that she described as "surrounded with flowers and kind wishes and interesting problems."

Faust, who officially took the reins Sunday, is laying the groundwork for a multibillion-dollar fund-raising campaign, planning for the new Allston campus, and launching an initiative to make the arts more central to Harvard's identity.

One of her toughest tasks is to corral a sprawling collection of 10 largely independent schools into a single university able to respond as one to competition in the sciences and other challenges.

A brief e-mail Faust sent yesterday greeting students, faculty, and staff seemed to reflect that concern. She wrote of "bridging our differences" and the "shared enterprise" of the community. Different schools within Harvard sometimes compete with each other for donations or preeminence in a field.

Sounding upbeat and enthusiastic in a phone interview yesterday, Faust said she would lead a dean's retreat next week to begin vigorous academic planning, not only within schools but between them.

That will help the development of the new Allston campus and lay the groundwork for the next capital campaign, she said.