Effect of seed storing duration and sowing year on the seedling establishment of grassland species in xeric environments

Abstract

Theavailability of seeds of native species in many countries for grassland restoration is limited; therefore, ex situ seed banks can gain importance as a source of germplasm in the future. We tested the usability of seed accessions of the Pannon Seed Bank for reintroduction with the aim to restore sandy grassland in Hungary. Seeds of 10 native sandy grassland species were seeded in the year of collection and after one or two years of storage. The establishment was estimated by counting seedlings along seeded transects for two vegetation seasons. This study produced the first numerical estimate we know about of native sand grassland species emergence in the field. A low establishment of the tested species was found, ranging from 0.002 to 8%. Within this range, Dianthus serotinus had the highest establishment, while Festuca vaginata, which was sown as matrix species, performed only medium establishment. The short-term storage (1 or 2 years) of seeds had no significant effect, except for F. vaginata, where seed storage had a positive effect on reintroduction success. The year of seeding had the highest influence on recruitment. Four species were found to emerge over two years instead of only the first year. Based on our results, the weak seed yield of certain years and the low supply of native seeds in the market can be mitigated by using stored seeds. It is recommended to use multi-year, scheduled seeding to reduce the negative impacts of particularly dry years and to increase the restoration success.