Abstract: As an indispensable component of forest ecosystems, species of herbaceous layer play a crucial role in regulating the community stability and ecological function of forests. We examined the relationships between the composition of understory community and the environmental factors in Pinus tabuliformis forests with different stand ages in Liaoheyuan Natural Reserve,aiming to reveal the main factors driving understory species composition. The results showed that stand age was an important factor driving the spatial variation of soil chemical properties in the forests. However, there was no linear relationship between forest age and the species diversity and richness index within the herb layer. The results from CCA ordination and Monte Carlo test showed that stand age, stand density, mean diameter at breast height, canopy density, and slope were main factors determining the composition of the herb layer, indicating that forest canopy structure determined the distribution pattern of herb layer plant communities in this region.

Key words: ecological vulnerability, “sensitivity-resilience-pressure” conceptual model, nature reserve., geodetector model