The Floristic Composition and Community Structure of the Forest Park Woodland, Queens County, New York
by Carsten W. Glaeser
City University of New York, Herbert H. Lehman College, Department of Biological Sciences, 250 Bedford Park Blvd., Bronx, NY 10468
Abstract
In 2000, a census was conducted within a wooded section of the 218-hectare Forest Park, in Queens County, New York, to document the current floristic composition and structure of the woodland community. All woody stems ≥ 2.0 cm diameter at breast height (DBH) within a permanent and contiguous 0.5-hectare (50 × 100 m) plot were identified, recorded, and measured for diameter, height, and x, y coordinates. The plot contained 771 stems from 22 woody species (15 genera and 13 families) reflecting a Shannon-Wiener index of 2.17 and a Simpson's index of 0.162. Five species were singletons, and three species were nonnative invasives. Stem DBH ranged from 2.0 to 116.7 cm, with a mean of 8.55 cm, and stem density was 1,542 stems per hectare. The largest-diameter trees were the oaks: red oak (Quercus rubra L.), black oak (Q. velutina Lam.), and white oak (Q. alba L.) (Fagaceae). The census revealed a young tree population largely dominated by characteristic pioneer species such as sweet birch (Betula lenta L., Betulaceae), black cherry (Prunus serotina Ehrh., Rosaceae), and the nonnative invasive Amur corktree (Phellodendron amurense Rupr., Rutaceae). The top dominant taxa based on Importance Values (IV) were Betula lenta, Quercus rubra, Phellodendron amurense, Cornus florida L. (flowering dogwood) (Cornaceae), and Prunus serotina, and the dominant arborescent family was Fagaceae, represented by Quercus rubra, Q. velutina, Castanea dentata (Marshall) Borkh. (American chestnut), and Fagus grandifolia Ehrh. (American beech). The top dominant taxa based on importance values within the small-diameter class were Betula lenta, Phellodendron amurense, Cornus florida, and Prunus serotina. The top dominant taxa within the large-diameter size class were Quercus rubra, Betula lenta, Q. velutina, and Cornus florida. Ecological dominance in this urban woodland is shifting away from its historical legacy as an oak, mixed dicot–dogwood forest. The observed disturbance patterns, the decline in traditional dominant tree species, the abundance of pioneer tree species across the diameter-size classes, and the continued colonization by Phellodendron amurense may be weighted factors imposing structural change throughout the woodland.
Key words: ecological dominance hierarchy; fragmented forests; forest census; frequency distribution; nonnative invasive species; pioneer species; randomization tests; species importance values; stem-size class; urban forest ecology