distribution and fruiting of red and black chokeberry (Aronia arbutifolia and A. melanocarpa) in a southern Appalachian fen1, The

Journal of the Torrey Botanical Society, Jul-Sep 2003 by Rossell, Irene M, Kesgen, Jenna M

ROSSELL, I. M., AND J. M. KESGEN (Environmental Studies Department, University of North Carolina at Asheville, Asheville, NC 28804). The distribution and fruiting of red and black chokeberry (Aronia arbutifolia and A. melanocarpd) in a southern Appalachian fen. J. Torrey Bot. Soc. 130:202-205. 2003.-Red chokeberry (Aronia arbutifolia (L.) Ell.) and black chokeberry (A. melanocarpa (Michx) EH.) are relatively common deciduous shrubs in southern Appalachian wetlands. Both are native species that produce pomes consumed by birds and mammals. There is growing interest in using these and other native plants in ecological restoration and wildlife management projects. However, few studies have focused on chokeberries, and published information is generally limited to casual observations and occasional estimates of percent cover. We examined the distribution and fruiting of red and black chokeberry in forested and early successional areas of a mountain fen in western North Carolina. In july 2002, we counted stems of each species in 40, 4 m � 4 m plots (20 plots in each area of the fen), and recorded the number of pomes on each fruiting stem. Two-thirds of all chokeberries occurred in the early successional habitat. Black chokeberry dominated both areas, comprising 72% of all chokeberry stems in the early successional area, and 79% in the forested area. Few pomes were observed in the forested area, and no red chokeberries fruited there. In the early successsional area, nearly equal percentages of each species produced fruit (8% of red chokeberries, and 10% of black chokeberries). However, red chokeberry produced significantly more pomes per stem, as well as 20% more pomes than black chokeberry, across the entire fen.

Key words: Aronia arbutifolia, Aronia melanocarpa, chokeberry, wetland shrubs, fruit production, southern Appalachian fen.

Red chokeberry (Aroma arbutifolia (L.) Ell.) and black chokeberry (A. melanocarpa (Michx.) Ell.) are deciduous shrubs in the family Rosaceac. Chokeberries have been classified at various times as Aronia, Pyrus, and Sorbus (Hardin 1973, Wofford 1989). Although Radford et al. (1964) indicate that black chokeberries lack rhizomes, other sources (Gleason and Cronquist 1991, Thunhorst 1993) report that both species are rhizomatous. Both species flower in the spring, and produce persistent pomes that arc consumed by birds and other wildlife (Miller and Miller 1999). In addition, the pomes of black chokeberry contain pigments that have been used commercially in Europe (Jeppsson 1999). The morphology, anatomy, chromatography, and pollination of both species, as well as an intermediate species, A. prunifolia (Marsh.) Rehder, have been examined in detail by Hardin (1973).

Red chokeberry has been documented in virtually every county in North and South Carolina, where it occurs in bogs, savannahs, and low wet woodlands throughout the coastal plain, piedmont, and mountains. In contrast, black chokeberry is restricted to mountain bogs and balds in the Carolinas (Radford et al. 1964). Regionally, red chokeberry is widespread throughout eastern North America, from the coastal plain as far inland as Kentucky and West Virginia. Black chokeberry occurs in similar habitats, although it is absent from the coastal plain and piedmont, and occurs farther inland, to Minnesota, Iowa, and Missouri (Hardin 1973, Gleason and Cronquist 1991).

To our knowledge, there are no ecological studies focusing on chokeberries. One or both species have appeared in species lists, such as in Weakley and Schafale's (1994) descriptions of the flora characterizing North Carolina mountain bogs. Pittillo (1994) reported mean coverage of 2% for each species of chokeberry at Flat Laurel Gap (a heath community characterized by open glades) in North Carolina.

Our review of the literature found chokeberries documented at several sites in West Virginia. At Big Run Bog, Wieder et al. (1981) noted that red chokeberry (but not black) was distributed throughout most of the bog, especially in areas dominated by Polytrichum hummocks. Mean coverage was 1.3%, and net primary production was 1 g�m^sup -2^�yr (the lowest contribution of the 20 taxa in their study). In contrast, S te wart and Nilsen (1993) reported black chokeberry in four out of five isolated Appalachian peat bogs (all four sites were in West Virginia), but did not mention red chokeberry.

In the West Virginia Allegheny Plateau, WaIbridge (1994) reported red chokeberry in four fens (all bryophyte/herbaceous communities), with black chokeberry occurring at the lowest elevation site. Both species also occurred in Alder Run Bog in West Virginia, where Gibson ( 1970) reported them on raised Polytrichum hummocks. Interestingly, black chokeberry occurred on the west sides of the hummocks, while red chokeberry occurred on the east sides. Both species also occurred along the margins of the bog and the adjacent forest.

Red and black chokeberry appear to be fairly common, although not highly significant, shrubs in southern Appalachian wetlands. Wetlands are scarce in the southern Appalachians, and most studies of wetland flora have been cursory, or have focused on dominant or rare species (Weakley and Schafale 1994). Increasingly, studies of native wetland plants are needed by wetland scientists for conservation and management purposes. For example, Thunhorst (1993) includes red and black chokeberry in a list of plant species suggested for wetland creation and restoration projects, and she includes information on their wildlife values. Our objective was to examine the distribution and fruit production of red and black chokeberry across a mountain fen in western North Carolina.