School Superintendent Carol Johnson said last night the Paul Dever, John P. Holland, William Monroe Trotter elementary schools and Harbor Middle School must either dramatically improve their scholastic results or face "serious consequences," possibly including shutting them down and sending students to other schools.

The four are on a list of 14 "turnaround schools" that are among the city's lowest performing schools and sit in a new "Circle of Promise" in Dorchester and Roxbury that includes neighborhoods "with a high concentration of underperforming schools and other challenges facing students and families," according to the school department. Johnson said Boston Public Schools will try to work even harder with local businesses, non-profit groups and church organizations to "ensure that residents have access to a seamless network of supports that help students succeed."

Improving these schools in particular is part of a five-year plan Johnson submitted to the School Committee last night that focuses on retaining and training the best teachers and principals while getting rid of "ineffective teachers and leaders." The plan also calls for more college-preparatory work - such as more Advanced Placement classes) and more arts, athletics and after-school activities. Johnson acknowledged, however, there will likely be no additional funding to make this possible (plan details).