Objectives Pinus sibirica is one of the constructive species in the forests of the northern Altai Mountains, and a representative and community-dominant species of the cold-temperate coniferous forests of Kanas, with only a small distribution in the mountainous areas of the Kanas River Basin in China. Intraspecific and interspecific competition are important factors regulating population structure, growth, and community dynamics. Clarifying the intraspecific and interspecific competition of P. sibirica, a rare and endangered species, has important ecological value for the systematic conservation of its population.

Methods In this paper, 101 trees were surveyed and analyzed based on the plant community survey, and the traditional survival pressure index model was modified and applied to compare the intraspecific and interspecific pressure changes of P. sibirica, and its changing law with the elevation gradient.

Results The results showed that: 1. The number of individuals in the P. sibirica population was small, accounting for 26.73% of the overall number, and the survival pressure index was 334.04; 2. Interspecific competition was the most important source of survival pressure, and the main competition objects were Betula pendula and Larix sibirica with survival pressure indices of 120.50 and 106.70, respectively; 3. The survival pressure on P. sibirica gradually decreased with increasing diameter class, and the value was relatively stable after DBH ≥ 20 cm; 4. P. sibirica had the highest survival pressure at 1376 m and 1387 m above sea level, and the survival pressure indexes were 112.93 and 141.54, respectively. Intraspecific and interspecific competition are important factors regulating population structure, growth, and community dynamics.

Conclusion In this study, we analyzed the survival pressure on P. sibirica populations with changes in diameter level and elevation through model fitting and explored the relative roles of these factors, which is important for investigating and predicting the process of population statistics. Furthermore, our findings provided a reference basis for the reasonable protection of populations.