Changes in pioneer community structure in an 0.8-ha central New York field were monitored during a year of cultivation and the 1st 2 years of abandonment. Species composition was unlike that of old fields in more southerly location, but similar to southeastern Michigan old fields. High diversity (Shannon-Wiener Index) and high proportion of perennials in the 1st year of abandonment and the establishment of a perennial grass stage during the 2nd year were attributed to persistence of propagules in the soil after 1 year of cultivation or possibly to rapid restocking due to the small size of the field. Maximum productivity occurred during June of the 2nd year of abandonment when dominance was established by Phleum pratense; however, total production over the growing season was lower than in the 1st year when dominance was shared by several species early in the growing season. Eighty-four percent of the species identified during the 1st year of abandonment were exotics, primarily European in origin. This percentage was much higher than reported for 1st-year fields in southeastern and mid-Atlantic regions. INTRODUCTION Secondary succession has been intensively studied in the eastern deciduous forest region of the United States. Much of the work has been done in the southeastern and mid-Atlantic Coastal Plain (McCormick and Buell, 1957; Odum, 1960; Woodwell and Oosting, 1965; Golley, 1965; Golley and Gentry, 1966; Levin, 1966), Piedmont (Oosting, 1942; Keever, 1950; Bard, 1952; Daniel and Platt, 1968; Hanks, 1971; Buell et at., 1971), and in the Midwest (Evans and Cain, 1957; Beckwith, 1954; Wiegert and Evans, 1964; Bazzaz, 1968). Very little has been published about secondary succession in the northeastern Appalachian Plateau. Swan (1970) studied the response of various seral stages to burning in S-central New York. Hurd et al. (1971) studied two abandoned hayfields in central New York in an attempt to ascertain the effect of nutrient enrichment on stability and diversity on the old-field ecosystem. This paper reports on the first phase of a study designed to compare succession on a central New York old field with old-field succession in southeastern, mid-Atlantic, and Midwestern regions. MATERIALS AND METHODS The study is being carried out at the Suny College at Oneonta Biological Field Station near Cooperstown. The elevation is 512 m (1680 ft) above sea level. The soil type is Volusia channery silt loam, an imperfectly drained, acid soil of glacial origin. Soils of this type typically have a fragipan at a depth of 30 cm (1 ft). These soils are used principally as pasture land, or for the production of oats or