Pollen evidence of vegetational change following early European settlement of Monhegan Island, Maine, northeastern U.S.A.

Postsettlemcnt vegetation changes beginning in the early 17th century were studied through comparing stratigraphic peat-pollen data with available historical evidence. The isolation of the site and the relatively long historical record were ideal for the study. Human disturbance of the vegetation was readily identified in the pollen diagram with a contemporaneous increase in sediment mineral matter. The effects were much the same as the changes associated with Neolithic forest clearance in Northern Europe. Settlement resulted in the introduction and expansion of several cultural weeds after grazing and cultivation of Zea mays began on the island in the first decades of the 17th century; Rumex acetosa-acetosella, Ranunculus acris type, Plantago major-media and several new Compositae and Umbelliferae species all appeared at that time. The response of the native species to settlement was varied. Because of the limitations of the palynologic method, the area of cultivated land and detailed kind of agriculture can only be estimated. The data suggest that although agriculture was intensive from time to time, it took place on a very limited local scale; fires, grazing, and lumbering were the major factors affecting natural ecosystems.