The Tawawa Woods Natural Landmark: II. Plant Species Composition and Recovery from Disturbance

Portions of Tawawa Woods, an oak-maple-beech forest community adjacent to Wilberforce (Greene Co.), OH, was granted landmark status in 1990 on the basis of its biodiversity, historic and cultural significance, and its potential as a site for studies of forest recovery from disturbance. Earlier, in 1974, Tawawa Woods was partially destroyed by a tornado that swept through nearby Xenia and vicinity. In 1988 and in 1999, we conducted studies of the plant species composition of Tawawa Woods with emphasis on tree species abundance, age, spatial distribution, and relative dominance. We used both plot sampling and point-centered quarter sampling methods. Although a total of 27 tree species were included in the samples, in 1988, 80% of the relative density was contributed by only eight species; notably, Acer saccharum, Prunus serotina, Liriodendron tulipifera, Fagus grandifolia, Sassafras albidum, Fraxinus americana, Quercus rubra, and Quercus alba. Comparisons of tree species abundance, distribution, and dominance as a function of sampling date and tree age class are discussed with regard to forest recovery from disturbance during the past 11 years, with emphasis upon the increasing importance of Acer saccharum. A case is made for elevating the Tawawa Woods Natural Landmark to "Natural Area" status based upon its strategic location in the Massies Creek corridor, and its ecological and historical significance. OHIO J SCI 103 (2):12-18, 2003 INTRODUCTION As part of an effort to identify and preserve natural areas, Tawawa Woods (Wilberforce Beech Woods), Wilberforce, OH, was included in a list of 30 "choice sites" in a report by Hunt (1956) and in an updated report by Herrick (1974). These reports, as well as one commissioned by the United States Department of Interior (Stein 1974), described the Tawawa Woods as a climax beech forest with diverse native herbaceous flora. As Stein's report was being written, Tawawa Woods incurred extensive damage from a tornado on 3 April 1974. Therefore, the report recommended that the woods be considered as a site for study of natural forest recovery from disturbance (Stein 1974). In 1990, 22.0 ha of the Tawawa Woods were designated as the Tawawa Woods Natural Landmark in a joint agreement between the Ohio Department of Natural Resources-Division of Natural Areas and Preserves and Central State University (Merkh and Silvius 1990). In addition to its biological significance, Tawawa Woods is a testimony of past historic and cultural events that have influenced its topography and soil properties (Lowell and others 2003). Although no quantitative ecological studies were initiated in Tawawa Woods until 1988, extensive research was being conducted on the subject of gap phase replacement (Runkle 1982; 1984). There was also a growing number of reports of the decline in recruitment of certain oak {Quercus) species in eastern deciduous forests (Abrams 1992; Lorimer 1993; Walters and McCarthy 1997), often in conjunction with the increasing Manuscript received 2 April 2001 and in revised form 26 February 2002 (#01-06). importance of sugar maple {Acer saccharuni) and red maple {Acer rubrutri) (Bonser and Aarssen 1994; Shotola and others 1992) and certain invasive exotic species such as the Asian honeysuckles {Lonicera sp.) (Hutchinson and VanKat 1997). Our report documents the plant species composition of Tawawa Woods with emphasis on tree species abundance, age, spatial distribution, and relative dominance at two sampling dates following the 1974 tornado; 1988 and 1999Our results are discussed with reference to current theory of gap phase replacement following disturbance, and the effect of disturbance upon successional trends involving certain oak {Quercus), maple {Acer), and honeysuckle {Lonicera) species. MATERIALS AND METHODS Physical Environment The Tawawa Woods Natural Landmark, Xenia Twp., Greene Co., OH (39° 43' N, 83° 52' W), is bounded by Wilberforce-Clifton Road on the west, Massies Creek on the north, and the Central State University (CSU) campus on the south and southeast (Fig. 1). Massies Creek is a major tributary of the Little Miami National Scenic River. Tawawa Woods Natural Landmark consists of approximately 22.0 ha and includes a riparian forest at elevations ranging from 265.0 to 270.0 m.a.s.l. adjacent to Massies Creek, and an upland forest community on north-facing slopes ranging from approximately 270.0 to 300.0 m.a.s.l. near the forest edge adjacent to the CSU campus. A 5.0to 100.0-m zone nearest the CSU campus and to the south and east of the current Landmark boundaries has a long history of more dominant human usage and disturbance (Fig. 1). This "perimeter region" is not included within the boundaries of the Tawawa Woods Natural Landmark. We have excluded it from our study because of its longer history of disturbance related OHIO JOURNAL OF SCIENCE J. E. SILVIUS AND OTHERS 13