Neighborhood Effects on Juveniles in an Old-Growth Stand of Longleaf Pine, Pinus palustris

We examined the effects of number, size and distance of adult trees on the survival and size of one-year-juveniles in an old-growth stand of longleaf pine. A total of 336 juvenile plots were established within an old-growth longleaf pine savanna in which locations and sizes of all adult trees were known. Plots were established in May 1988 following a mast year in the autumn 1987. In May 1989, survival and sizes of juveniles were measured. Adult trees > 1 cm dbh located within 30 m of each of the 336 juveniles plots were classified based on diameter and distance to plots. Repression analyses were conducted in which survival and sizes of juveniles were related to total dbh and number of all neighbors within defined size and distance classes. Large neighbors (>30 cm dbh) influenced juvenile survival up to 18 m from plots and influenced juvenile sizes up to 15 m from plots. Our data thus suggest that there are strong influences of neighbors on very early life stapes of longleaf pine in the old growth stand. Patches of juveniles begin to form in areas where impacts of neighbors are minimal (i.e. few large trees in the vicinity) is early as the first year of growth. Locations of sites most suitable for recruitment into the old-growth stand - some distance from large trees - thus are predictable at the time of seed dispersal