Spatial patterns of trees of different size in borealPinus sylvestrisforest sites with different fire histories

Abstract

The spatial distribution of living trees of different size-classes was examined on two sites with different fire histories in a mature Pinus sylvestris L. dominated forest in eastern Finland. The study area was a 4-ha square plot, which was divided into two parts based on fire history analysis. In one part, the last fire event was a stand-replacing fire in the early 19thcentury, after which the whole stand regenerated, while the other part of the study plot was subsequently burnt by a surface fire in 1906. For the analyses, the trees were divided into five height-classes, reflecting competitive hierarchy. Spatial patterns of different tree height-classes were analysed using formulae for spatial autocorrelation with categorical data. In both areas, saplings showed an aggregated and overstorey trees a random spatial pattern at all scales studied. The other tree height-classes showed aggregated or random spatial patterns depending on the area and distance class. Generally, similar tree height-classes tended ...