Spatial Distributions and Spatial Associations of Dominant Tree Species in Korean Pine Broad leaved Old-Growth Forests in Changbai Mountains

Pair correlation function g(r) was used to study the spatial patterns of five dominant species (Finns koraiensis, Quercus mongolica, Tilia amurensis, Fraxinus mandshurica, Acer mono) in Korean pine and broadleaved multi-species forests in the Changbai Mountain areas. The spatial distribution at different growth stages (from saplings to small diameter trees and big trees) were studied, as well as the spatial associations of different species at different growth stages. Structural characteristics and distribution of canopy gaps, spatial relationships between canopy gaps and tree species with a height of less than 11.2 m were also explored by studying the canopy horizontal projection. Pinus koraiensis and Quercus mongolica were distributed randomly and Acer mono was in a clumped pattern at some studied scales (r=1-11 m, 13-16 m, 20 m, 33 m and 43 m scales). Fraxinus mandshurica (at smaller scales r=5 m) and Tilia amurensis (r=1-2 m, 9-11 m and 16-18 m) occurred in a clumped distribution. Among 10 species pairs which consisted of five dominant tree species, there were three species pairs (Pinus koraiensis and Tilia amurensis, Pinus koraiensis and Acer mono, Acer mono and Fraxinus mandshurica) which showed mutual attraction at several scales. Three species pairs (Pinus koraiensis and Fraxinus mandshurica, Tilia amurensis and Fraxinus mandshurica, Qercus mongolica and Acer mono) showed spatial exclusion. Quercus mongolica and Fraxinus mandshurica appeared exclusions at r=21 m scale and attractions at r-46 m scale. The canopy gaps mainly occurred as a random distribution within the plot, with the exception of a regular distribution at the distances of r=6 to 11 m.