Residents with a passion for land preservation are being asked to consider joining the Conservation Restriction Advisory Committee, which has one vacancy. The panel encourages landowners and developers to keep land in its natural state by putting it under a perpetual conservation restriction. In addition, the Land Stewardship Committee, a permanent subgroup of the Conservation Commission, is seeking volunteers. The stewardship committee assists the commission in managing about 1,100 acres of town-owned conservation land. The committee also works on outreach programs to promote conservation, identify and manage invasive species, wildlife ecology, forestry, environmental education, and preservation of agricultural lands, cultural landscapes, and rural vistas. For more information on either role, contact Sylvia Willard, the town’s conservation administrator, at 978-369-0336. Full story for BostonGlobe.com subscribers.