Abstract: Based on the population life table and the theory of survival analysis, the static life table of Pinus tabuliformis population in Liaoheyuan Nature Reserve was complied by using the “spacefortime” substitution approach and the stagesmoothing technique. The graphs of mortality rate curve, killing power curve, survival rate curve, and survival function curve were also sketched. The results showed that P. tabuliformis population presented a fluctuating trend of development and would experience three death peaks. The age structure of P. tabuliformis population showed an inverted Jtype pattern and the number of seedlings was large. However, due to the high intensity selection through environmental sieve in the stage from seedling to sapling (from age class 1 to 2), the P. tabuliformis population would experience the first death peak. The second and the third death peak occurred during the transition period from the subforest layer to the main forest layer (from age class 7 to 8) and the later stage of growth (from age class 11 to 12), which were caused by the competitioninduced selfthinning and the physiological death, respectively. The survival curve of P. tabuliformis population was similar to the DeevyII type, thus the population was classified as a stable one. The four survival functions indicated that the population dynamics of P. tabuliformis was characterized by decreasing in the early stage, being stable in the medium stage and depressing in the later stage.

Key words: nutrient cycle, plant organ, homeostasis, adaptive strategy, C:N:P