Spatial patterns of soil and vegetation in a 40-year-old slash pine (Pinus elliottii) forest in the coastal plain of South Carolina, U.S.A.

摘要

A study was conducted at the Savannah River Site in a 40-year-old slash pine (Pinus elliottii Engelm.) plantation in South Carolina to characterize the spatial patterns of soil, forest floor, and plant community variables and to investigate correlations among the variables. Spatial soil and litter samples were collected on five 0.25-ha plots. The spatial patterns of the variables were characterized by global variance, autocorrelation range, and patchiness. The cross-variable relationships were explored using Pearson's correlation tests to examine functional heterogeneity (i.e., to determine if structural heterogeneity reflected ecological processes). Variances of the variables calculated without regard to spatial position (i.e., global variance) were generally low. Average range of spatial autocorrelation was about 58 m for the forest floor variables, 11 m for soil variables, 11 m for basal area of large pines (>30 cm diameter at breast height), and less than 11 m for basal area of smaller pinesor other woody species. Few strong spatial correlations among the forest floor and soil variables were observed. Spatial patterns of pines and hardwoods were weakly correlated with litter quality patterns and soil nitrogen. We conclude that the sample plots were generally homogeneous and that differences in soil resource levels were probably too small to influence spatial pattern of vegetation in this 40-year-old plantation.