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.

The present and future of grassland restoration

“…Sown species established best in gaps as a result of low weed abundance, and began to expand into surrounding non‐gap areas within 5 years, illustrating the potential of localized disturbances for broader‐scale restoration. Kövendi‐Jakó et al (2021) also showed the importance of seed sowing for re‐establishment of sandy grasslands in Hungary. They found, however, that establishment varied among years and argued that repeated seeding could be advantageous under stressful conditions.…”

Efforts at the beginning pay off: sowing grasses and forbs simultaneously supports restoration of species-rich grasslands and improves weed control in ex-arable land

“…One reason for this may be that under eld conditions a high intraspeci c competition was present between the individuals of species with high germination rate and negative frequency-dependence resulted in a decreased survival rate of individuals [50] . Another reason can be that in the eld unfavourable post-germination conditions resulted in high mortality of seedlings, so the establishment of species with lower germination rate and gradual emergence may have been more successful [42,51,52] .…”

Co-seeding grasses and forbs supports restoration of species-rich grasslands and improves weed control in ex-arable land

“…One reason for this may be that under field conditions a high intraspecific competition was present between the individuals of species with high germination rate and negative frequency-dependence resulted in a decreased survival rate of individuals 52 . Another reason can be that in the field unfavourable post-germination conditions resulted in high mortality of seedlings, so the establishment of species with lower germination rate and gradual emergence may have been more successful 42,53,54 .…”