Effects of different habitats on Achnatherum inebrians (Hance) Keng ex Tzvelev (drunken horse grass) soil seed banks and aboveground vegetation

The soil seed bank, as a potential source of ground vegetation renewal, plays an important role in the natural recovery and succession of vegetation as well as in the construction of ecosystems. To clarify the characteristics of the soil seed bank of Achnatherum inebrians and its relationship with the aboveground vegetation, the soil seed bank density, species composition and aboveground vegetation of three different grassland types, namely, desert, steppe and meadow, were investigated by means of field survey sampling and indoor germination experiments. The results showed that the seed bank densities of the three habitats were ranked as desert (1 422.22 seeds/m2), steppe (2 077.78 seeds/m2) and meadow (3 722.22 seeds/m2). The numbers of species were 16, 11 and 17, respectively. With respect to the vertical allocation, the soil seed banks in each habitat were shallow, and the seeds were mainly concentrated in the soil surface layer (0-5 cm). The species richness of the soil seed banks in the three habitats was higher than that of the aboveground vegetation, but there were some differences in richness, evenness and dominance. The species richness and diversity of soil seed banks and aboveground vegetation in meadow habitats were higher than those in desert and steppe habitats, indicating that the soil seed banks and aboveground vegetation in meadow habitats had higher stability. There was a significant positive correlation between the density of temporary soil seed banks and the density of aboveground plant communities in grassland habitats. The results may provide some reference for the prevention and control of Achnatherum inebrians in the three habitats.