摘要：We aimed to compare the properties of seed banks in different types of Robinia pseudoacacia stands and different substratum layers. We established four Black locust plots (each 50 × 50 m) that included two second-generation stands and two third-generation stands. Spatial coordinates, diameter at breast height, and the heights of all trees were measured in the four plots. In each plot, we set a total of 259 points using the regular grid design method. At these points, we sampled the seed banks in the litter and soil (0-5 cm) layers. The coordinates of the 259 points were recorded. After the samples had been collected and screened, a germination trial was performed using the collected seeds from the different layers and stands. We used variogram and kriging interpolation geostatistical methods to analyze the distribution of the seed banks. A kernel density estimation map was generated to examine the relationship between the seed bank and trees in each stand. The results showed that seed bank density was high in the four stands (4005-7325 seeds.m-2), and was higher in the third-generation stands (6085 and 7325 seeds.m-2) than in the second-generation stands (4005 and 5659 seeds.m-2). The seed bank density in the litter layer (3225 seeds.m-2) exceeded that in the soil layer (2164 seeds.m-2). The spatial pattern of the seed banks varied among different stands and was positively correlated with the distribution of trees in each stand. Furthermore, we found that spatial autocorrelation in the seed banks occurred at a variety of scales. Seeds in the litter layer were significantly more active than those in the soil layer; the germination rate varied from 6.67% to 28.89%. The findings of this study suggest that the Robinia pseudoacacia plantation in the Luoning area may exhibit potential for regeneration from seeds, and this will be the focus of our future studies.
