Conservation of three historic forest landscapes in the New York metropolitan area

Conservation of historic forest landscapes at national historic sites involves maintaining and replacing the historic trees as well as removing modern trees. Tree stem inventories in 1995 and 2013 are compared to assess conservation efforts for the historic forest landscapes of three U.S. National Historic Sites located in the New York metropolitan area: Glenmont of Thomas Edison; Sagamore Hill; and Vanderbilt Mansion. The terms alien tree taxa and native tree taxa are defined in regard to the eastern United States. Among the three historic forest landscapes there are 77 alien tree taxa, but only Abies nordmanniana, Acer palmatum, Acer platanoides, Aesculus hippocastanum, Fagus sylvatica, and Magnolia × soulangeana are present in Glenmont, Sagamore Hill, and Vanderbilt Mansion. Of the 56 native tree taxa, there are 15 species common to the three historic forest landscapes. Paired t-tests (P ≤ 0.05) of taxa stem counts from the 1995 and 2013 inventories reveal the alien and native tree stems for historic and modern trees declined significantly at Sagamore Hill. Both alien and native historic tree stems decreased significantly at Glenmont. Only alien historic tree stems were significantly smaller at Vanderbilt Mansion. Differences in forest landscape management efforts among the national historic sites provide explanations for the significant decreases in alien and native trees at Glenmont, Sagamore Hill, and Vanderbilt Mansion.