Spatial heterogeneity in the determinants of woody plant invasion of lowland heath

ABSTRACT Questions: 1. What is the scale and extent of spatial variability in factors affecting Betula invasion of heaths? 2. How much effect does each factor have on within-patch patterns of invasion? 3. How can this understanding aid in managing Betula invasions? Location: Lowland heath of southern England. Methods: Determinants of Betula (both B. pubescens and B. pendula) invasion: biomass density, necromass density, mean vegetation height, P-availability, soil water content and total Betula seed bank density, were measured at two sites on a 5-ha sampling grid. Spatial pattern was assessed using geostatistics. Contributions of each determinant to within-site heterogeneity in predicted Betula seedling densities were estimated by varying variables over their full and interquartile ranges in a statistical model derived from experimental data. Results: Salient spatial trends were revealed: strong autocorrelation over distances of 150 m) in v...