【Title】Distribution Patterns and Associations of Dominant Tree Species in a Mixed Coniferous-Broadleaf Forest in the Changbai Mountains
【Author】ZHANG Meng-tao1, KANG Xin-gang1, MENG Jing-hui1, ZHANG Li-xin2,
【Addresses】1 Key Laboratory for Silviculture and Conservation Ministry of Education, Beijing Forestry University, Beijing 100083, China; 2 Yunnan Forest Institute, Kunming 650204, China
【Citation】Zhang MT, Kang XG, Meng JH, et al. (2015) Distribution patterns and associations of dominant tree species in a mixed coniferous-broadleaf forest in the Changbai Mountains. Journal of Mountain Science 12(3). DOI: 10.1007/s11629-013-2795-1
【Abstract】In 2012 a plot was established with 1-ha area in a mixed coniferous-broadleaf forest in the Changbai Mountains, northeastern China for examining local forest processes, structure and succession. A method of O-ring statistics (pair-correlation function) was applied to analyze the spatial patterns and associations of the dominant species within different vertical layers. After the evaluation by their importance values, six tree species (or group) (i.e. Abies nephrolepis, Picea jezoensis, Pinus koraiensis, Tilia amurensis, and species group of Betula ssp. and species group of Acer ssp.) were determined as dominant trees species. It was found that some of these species exhibited closely clustered distributions at fine distances. As spatial distance increased, a random or even regular distribution gradually appeared with the exception of the upper layers of A. nephrolepisand P. koraiensis, and the lowerlayers ofP. jezoensis, P. koraiensis and Betula ssp.,which were substantially randomly distributed. Intra- and inter-species spatial associations varied in accordance with species, tree height and reciprocal distances. Positive associations were observed between the lower and upper height classes of trees of the same species (except for that of P. jezoensis) at fine distances. This may be owing to limited seed dispersal and geological heterogeneity. The aggregation intensity declines with increasing distances and this consistent with the predictions of self-thinning. Some coniferous trees (e.g. Pinus koraiensis) in the lower height class were positively associated with T. amurensis and group of Betula ssp. of the upper height class at some distances, suggesting that saplings of coniferous trees occupy a broader niche and can grow well under the canopy of the adult of broad-leaved trees. Negative associations were observed between upper coniferous treesand lower broad-leaved trees and between upperP. jezoensis and lower P. koraiensis, suggesting that a canopy of these trees might not provide suitable environment for the survival, establishment, and growth of lower individuals, corresponding well to Janzen-Connell hypothesis.
【Keywords】Mixed coniferous-broadleaf forest; O-ring statistics; Spatial pattern; Spatial association; Null model