Journal of the Torrey Botanical Society 134(4), 2007, pp. 552–569 The naturally occurring historical and extant flora of Central Park, New York City, New York 1857–2007 Robert DeCandido1,2,3 Hawk Mountain Sanctuary, 410 Summer Valley Road, Orwigsburg, PA 17961 N. Calvanese Central Park Conservancy, 14 East 60th Street, New York, NY 10022 Regina V. Alvarez Central Park Conservancy, 14 East 60th Street, New York, NY 10022 Matthew I. Brown and Tina M. Nelson Central Park Conservancy, Soil, Water and Ecology Lab, 830 Fifth Avenue, New York, NY 10021 DECANDIDO, R. (Hawk Mountain Sanctuary, 410 Summer Valley Road, Orwigsburg, PA 17961), N. CALVANESE (Central Park Conservancy, 14 East 60th Street, New York, NY 10022), R. V. ALVAREZ (Central Park Conservancy, 14 East 60th Street, New York, NY 10022), M. I. BROWN (Central Park Conservancy, Soil, Water and Ecology Lab, 830 Fifth Avenue, New York, NY 10021), and T. M. NELSON (Central Park Conservancy, Soil, Water and Ecology Lab, 830 Fifth Avenue, New York, NY 10021). The naturally occurring historical and extant flora of Central Park, New York City, New York 1857–2007. J. Torrey Bot. Soc. 134: 552–569. 2007—This vascular flora of Central Park, New York County, New York State is based upon field work by the authors in 2006–2007 combined with three 19th century plant lists, and specimens held at metropolitan herbaria collected from 1885–2006. Altogether, 106 families, 351 genera, and 583 species are reported. The largest family in Central Park in both the historical (1858 to 1910) and modern period (1985 to 2007) is the Asteraceae. The largest genera are Polygonum, Quercus,andAster. Analyses of the ecological characteristics of the historical flora show that species indicative of riparian areas including ponds, swamps, wet meadows and woods, were formerly common in the area that was developed into Central Park. Twenty- one species would have special New York State Natural Heritage Program designations if they were extant today. In the 19th and early 20th century, native plant species (255; 74%) far exceeded non-natives (91; 26%)in Central Park. However, 70% (178) of the native plants recorded in the historical time period have been extirpated. Most extirpated native species were herbaceous plants (111; 62%), and were significantly more likely to prefer wet meadows and woods than drier habitats. By comparison, in our field work in 2006–2007 and examination of BBG and NYBG plant collections, we found 362 species, most of which were non-native plants (211; 58%). Three species we collected have special status designations in New York State: Eclipta prostrata, Eupatorium serotinum,andPtelea trifoliata. We recommend the continuation of native plant restoration efforts in Central Park, with an emphasis upon re-establishing herbaceous species characteristic of meadows, open woodlands and riparian areas, as well as increasing the diversity and number of Quercus spp. in the forest. Combined with educational outreach that calls to attention the environmental history of Central Park, much can be done to make people aware of the significant role urban areas can play in conservation efforts. Key words: biotic homogenization, Central Park, historical flora, New York City, restoration, urban. Central Park (Fig. 1) is one of the best 1 This paper is dedicated to two distinguished known urban parks in North America. At New York City naturalists who have studied plants 341.2 ha., it is the fifth largest green space in in Central Park for more than 50 years: William Schiller of the Education Department of the New York City (NYC). The park was American Museum of Natural History, and Sarah established in 1853 when the land was M. Elliott, author and illustrator. We also thank obtained via decree by the New York State these colleagues for their expertise and advice: N. legislature. After substantial construction, Wagerik, E. Levine, D. Allen, H. Becker, N. Dicker, landscaping, and planting, the park was A.M. Greller, R. S. Lieberman, R. E. Loeb, L. Miller, S.C. Miller, R. Schutz, A. Stillman, H. H. opened to the public in 1858 (Richards 1861, Stillman and S. J. Wiley. M. F. Baron labeled pressed plant specimens and organized the herbar- 3 Author for correspondence: E-mail: rdcny@ ium. A. Arrowsmith designed the map. earthlink.net 2 Present address: 1831 Fowler Avenue, The Received for publication January 18, 2007, and in Bronx, New York 10462. revised form August 28, 2007. 552 Journal of the Torrey Botanical Society tbot-134-04-13.3d 7/12/07 11:10:12 552 Cust # 07-RA-002 2007] DECANDIDO ET AL.: FLORA OF CENTRAL PARK, NEW YORK CITY 553 Cook 1869). By 2000, it was estimated that 25 million people visit Central Park each year (The Trust for Public Land 2006). People have a long association with Central Park. In 1853, there were approximately 1600 residents in the area that would become the park (Rosenzweig and Blackmar 1992). At that time, a community of mostly African- American citizens lived in ‘Seneca Village’ between present day 81st and 86th Streets near the west side. Businesses, including leather tanning works and slaughterhouses, also operated in the park. Up until 1858, it is likely that anthropogenic activities such as cutting wood for fuel, fire, and shelter maintained a diversity of habitats in the area of Central Park including open fields, swamps, meadows, and early successional woodlands. During the construction phase beginning in 1858, almost 1000 workers were hired for landscaping projects. By 1873, at least 10 million cartloads of material had been hauled through the park. Approximately four million trees, shrubs, and plants, representing more than 1000 species were planted (Barlow 1977, Graff 1985, Rosenzweig and Blackmar 1992). Today, there are about 200 workers employed by the Central Park Conservancy as gardeners and others, working directly with the park’s plants and landscape. Beginning in the mid 19th century, research- ers documented the biodiversity of Central Park including its terrestrial plant species (Rawolle and Pilat 1857), fresh water flora and fauna (Gratacap and Woodward 1884), and breeding birds (Woodruff and Paine 1886). In the last 25 years, geologists have mapped the rock formations and geo- logic history of the park (Taterka 1987, Merguerian and Sanders 1993). Other research has assessed long-term changes in woody plant species of the park (Loeb 1993), as well as atmospheric particulates found in sediment cores extracted from the Central Park lake (Chillrud et al. 1999, Yan et al. 2005). However since the 19th century, bota- nists have not compiled a complete flora of the park. r FIG. 1. Map of Central Park, New York Coun- ty, New York. Journal of the Torrey Botanical Society tbot-134-04-13.3d 7/12/07 11:10:19 553 Cust # 07-RA-002 554 JOURNAL OF THE TORREY BOTANICAL SOCIETY [VOL.134 Most people are unaware of the great present in Central Park in the past? Are any diversity of plant species found in NYC. New York State listed native plants found in Sanderson and Brown (2007) mapped 54 the park today? By answering such questions, ecological communities that once existed on we could provide guidance to park managers Manhattan Island prior to the 18th century. As interested in restoring native plant species recently as the late 19th century, 30 of the 58 diversity to natural areas of the park, and native orchids of New York State could be trace an environmental history of Central Park found in NYC, with 21 species occurring on since the mid-19th century. Manhattan Island (Denslow 1924, DeCandido et al. 2004, Lamont in press). Materials and Methods. STUDY SITE. Central McKinney (2006) has shown that urbaniza- Park is located in the center of Manhattan tion produces biotic homogenization of plant (New York County) in the southeastern part species diversity in cities and suburbs in North of New York State (40u 469 120 N, 73u 589 10 America and elsewhere. Uncommon and rare W; Fig. 1). The park is rectangular, approxi- native plant species are often extirpated locally mately 4.0 km long and 0.8 km wide, trending as urbanization increases, while on a regional 29u NE (Taterka 1987) stretching from 59th scale, synanthropic (primarily non-native) Street (Central Park South) north to 110th plants become more widespread (see Chocho- Street. The original northern boundary of the louskova and Pysek 2003, Standley 2003, park was at 106th Street in 1853, but in 1863 Clemants and Moore 2005). This process has additional land was added up to 110th Street been especially pronounced in port cities of the (Olmstead and Kimball 1928). The lowest northeastern United States (Clemants and point of the park is 4.5 m above sea level (asl) Moore 2003). The establishment of gardens at the Harlem Meer at the northeastern section or other exotic plantings further augments of the park. The highest point (excluding man- diversity of alien species in cities (Smith et al. made structures) is 41.3 m asl atop Summit 2006). Also, urbanization creates barriers to Rock near Central Park West and 83rd Street. migration by eliminating direct biotic corri- Today, ballfields, lawns, formal gardens, dors that native plant species can utilize to re- paved recreational areas and roadways form establish populations in city parks. As a result, the major part of the park. However, there still despite the overall increase in alpha-level remain three significant natural areas man- biodiversity in cities, the loss of unique native aged by Central Park Conservancy staff: the plants impoverishes urban parks and other North Woods and adjacent Wildflower Mead- natural areas. Urban habitats most affected ow (36.4 ha), the Ramble (14.6 ha), and have been wetlands, moist meadows, and Hallett Sanctuary (1.6 ha).