A large portion of the Kendall Square rooftop garden was fenced off as of Thursday. Part of the garden will be replaced by a two-story connector building occupied by Google. The approval process for the connector has been quite controversial, with the City Council approving the work only after believing the Cambridge Redevelopment Authority had done so, though in fact the Authority had no quorum at the time. Last week, CRA Executive Director Joseph Tulimieri resigned amidst questions about his salary and compensation. City Manager Robert W. Healy has appointed Susan Glazer from the city’s Community Development department to head up the CRA in the interim. Both Tulimieri and administrative assistant Tracy Mercer, who also resigned last week, did not respond to requests for comment.