The researchers studied the age structure and spatial patterns of Betula platyphylla populations in Wulashan Nature Reserve. They analyzed tree diameter to understand tree age and used a method called Ripley's K-function to study how the trees were distributed. The study found that the population had a pyramid-shaped age structure, with good natural regeneration. Older trees were more likely to die due to competition for space and resources. Young and middle-aged trees tended to cluster together, while older trees were more randomly distributed. Overall, as the population aged, it transitioned from clustered to random distribution.