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Considered

Carbon-based species

When the old path of Centre Street on the west side of Harvard’s Arnold Arboretum was straightened, a set of “invasive” black locust trees soon took root in the former road bed. (Black locust, or Robinia pseudoacacia, is on Massachusetts’ invasive species Prohibited Plant List.) It is like that at the Arboretum: rogue species rising among accessioned species. Recently, several of these locust specimens were selected for their exceptional durability as building material and removed for the purpose of new footbridges, each simple timber structure providing improved access to the Arboretum grounds. This is not primarily a story of public accessibility or about cunning carbon cycles, however. In today’s political and ecological climate, it is above all a reminder of how species interact, how none is invasive but rather entangled in rich, evolving sets of mutualities and feedbacks to be maximized through design.