FOREST COMMUNITY COMPOSITION AND JUVENILE RED SPRUCE (PICEA-RUBENS) AGE-STRUCTURE AND GROWTH-PATTERNS IN AN ADIRONDACK WATERSHED

Characteristics of juvenile Picea rubens Sarg. (red spruce) age- and size-structure were evaluated as well as terminal and lateral growth increments for P. rubens saplings among forest community types and microtopographical positions on the Woods Lake watershed in the western Adirondack mountains, New York, USA. The effects of a watershed liming with 6.89 t.ha(-1) of pelletized CaCO3 on the growth of P. rubens saplings were evaluated in reference and treated subcatchments for the year prior to and three years after treatment to determine if a calcite application initially affected growth. Forest community types at Woods Lake were similar to other northeastern forests in composition and structure, but will likely experience changes in overstory composition as the dominant species, Acer rubrum L. (red maple), is replaced. Fagus grandifolia Ehrh. (American beech) was codominant in the overstory with A. rubrum, and was dominant in the understory. Picea rubens saplings were more frequently found on mounds than other microtopographical positions, but not on mounds that were of recent origin. Picea rubens saplings had an unimodal age-structure characteristic of an even-aged population, which suggests a pattern of episodic regeneration coincident with local windthrow disturbance. Picea rubens that occurred on mounds, rocks, and intact areas tended to be larger and older than those found in pits. The establishment and survival of juvenile P. rubens were limited by the availability of microsites coincident with good seed years, and the suitability of microsites for growth once stems were established. Terminal and lateral growth increments of P. rubens saplings were similar among microtopographical positions and between reference and Limed subcatchments before and in the two years after liming. In 1992, the terminal increment of P. rubens was not different from the 1991 terminal increment on treated subcatchments, but in reference subcatchments the terminal increment was less than in 1991. The potential role of P., rubens in future forests is discussed.