| Abstract: | Aims Exploring the spatial distribution pattern and the association among different developmental stages of Picea crassifolia populations can reveal the succession patterns of the populations, infer their potential ecological mechanisms, and thus provide guidance for the configuration, planting, forest management and management of the populations.Methods Based on the survey data of a P. crassifolia dynamic monitoring plot (10.2 hm2) in Dayekou basin, Qilian Mountains, China. The species composition and diameter structure of the community were analyzed, and the point pattern method was used to analyze the spatial distribution pattern and spatial correlation of P. crassifolia populations at different age stages through univariate pairwise correlation functions and bivariate pairwise correlation functions.Important findings The results showed that: (1) The diameter class structure of P. crassifolia population was an inverted “J” shape, indicating that the population was a growing population and the population was in good natural renewal status. (2) The individuals of four diameter classes in the P. crassifolia population were aggregated at a small scale, but as the spatial scale increased, the aggregation intensity gradually weakened and tended to be randomly distributed. Moreover, individuals of smaller diameter classes used to be aggregated, but as the diameter increased, they also tended to be randomly distributed. (3) The big trees in the P. crassifolia population were negatively correlated with other diameter classes at a small scale (<4 m). As the scale increased, the big trees and young trees showed a positive association and the correlation decreased with increasing scale. However, as the scale increased, big trees showed no or weakly negative correlation with small and medium trees. In addition, the spatial association of individuals with similar diameter classes showed positive or no association. As the difference between individual diameter classes increased, their spatial association changed to no or negative association. In conclusion, the spatial distribution patterns and association of P. crassifolia population in Dayekou Basin of Qilian Mountains varied with the spatial scale and developmental stage, which was the result of the combined effects of the population’s bioecological characteristics, intraspecific and interspecific relationships, and environmental conditions. |
