Rooftop garden pioneer takes key USDA post

Another Bay Stater heads to Washington: Tufts professor Kathleen Merrigan has been tapped for the No. 2 slot at the US Department of Agriculture. Appropos of yesterday's posts on urban agriculture and farmer's markets, it's worth noting that Merrigan has a stake in making cities more green. In 2007, Marjorie Howard mentioned Merrigan in a Tufts Journal piece on the university's experiments with "green roof" gardens in urban areas:

Merrigan … envisions a green-roof corridor, perhaps along the Mystic River Watershed, a 76-mile area that encompasses 21 communities north and west of Boston. “If we go to [Boston Mayor] Thomas Menino and [U.S. Rep.] Edward Markey, D-Mass., we want to be able to share with them what we think the ramifications are and what are the policy potentials as environmental interventions,” she said.

Will Merrigan's new federal post be a boost to mini-farms atop Boston's skyline?

…green roofs act as natural filters because the plants remove contaminants, such as nitrogen and phosphorous, from rainwater and carbon dioxide from the air. The rooftop plants absorb water, which then evaporates and creates a cooling effect. Where there is a critical mass of green roofs, they can actually reduce the effects of what are known as urban heat islands — metropolitan areas where expanses of asphalt and concrete make cities warmer than surrounding areas. Green roofs also keep rainwater from washing into storm drainage and sewer systems, where it is treated unnecessarily at wastewater treatment plants. They provide habitats for birds and other urban wildlife.