Environmental change in the terrestrial vegetation of Bermuda: Revisiting Harshberger (1905)

In June of 1905 the pioneer ecologist John W. Harshberger visited Bermuda to investigate sand dune plants, survey the main plant formations and collect herbarium specimens. His specimens and observations are of significant value as a baseline to understand the extraordinary ecological change due to plant invasion that the island has experienced over the last 100 years. His observations on the vegetation types of Bermuda are contained in a six-page summary of a talk that he gave to the Academy of Natural Sciences of Philadelphia. He divided the terrestrial vegetation of the island into eight types. While five of these, mangrove swamp, salt marsh, brackish marsh, cliff rock, and sand dune, have vegetation that is lightly invaded and still recognizable from his descriptions, three others, cedar forest, limestone sinks forest, and scrub, have been altered by invasive plants beyond recognition except in a few small nature reserves that are actively managed against invasives. The seed rain from the introduced starling feeding on the fruits of invasive plants is heavy and ubiquitous. Any conservation of terrestrial vegetation now requires weeding against invasives in perpetuity, a "conservation treadmill" that needs to be budgeted for and carefully applied if conservation is to succeed.