The Changing Flora of the New York Metropolitan Region

by Steven E. Clemants and Gerry Moore

Brooklyn Botanic Garden, 1000 Washington Avenue, Brooklyn, NY 11225

Abstract

We statistically analyzed 100 years of herbarium specimen data for woody plants in the New York metropolitan region in order to measure the floristic changes of this area. Change Index values were computed for 224 of the region's 556 woody species to provide a specific measure of whether these species are expanding, contracting, or stable. The results show that, in general, nonnative invasive species are spreading rapidly in the region, while native species are in slight decline.

Key words: Chimaphila, ecological change; Ericaceae; herbarium; invasive plants; Lonicera; New York City, urban flora