50 YEARS OF CHANGE IN AN UPLAND FOREST IN SOUTH-CENTRAL NEW-YORK - GENERAL PATTERNS

Long-term changes in the composition and structure of an upland hardwood forest in south-central New York were quantified by resurvey of 22 permanent plots originally established in 1935. In 1935 most of the forest consisted of stands recovering from disturbance by logging in the late 19th century, and most of the plots underwent timber stand improvement in 1934 that reduced basal area by an average of about one-third. Average basal area nearly doubled during the 50 year period, and basal area of the individual plots converged from widely disparate values in 1935 to about 32 m2/ha in 1985. Size structure of the forest changed markedly over the 50-year period reflecting high recruitment of the shade tolerant species-sugar maple, beech, hemlock-as well as a significant decline in density of suppressed sub-canopy trees (10-20 cm DBH) mostly as a result of mortality. Although basal area of the mid-tolerant species-white ash, red maple, basswood-remained high, recruitment of these species was limited and in the continuing absence of large-scale disturbance the forest appears to be moving towards a composition dominated by the highly shade tolerant species.