Do small-scale gaps in calcareous grassland swards facilitate seedling establishment?

Abstract

In this study we analyzed gaps originated in different seasons of the year vs. places of close vegetation in calcareous grasslands in terms of their suitability for seedling germination and establishment. Gaps, irrespective of the time of their origin, significantly promoted seedling emergence as compared with close swards. However, the season of gap creation influenced the rate of seedling germination/emergence. Seedlings occurred more frequently in autumn and spring gaps than in the summer ones. The highest mean number of seedlings and of their species were noted in autumn openings. However, the subsequent survival of seedlings in autumn gaps was low. On the contrary, in spring gaps juveniles occurred with the significantly highest mean number, frequency and species richness. The above results pointed to the positive, although very limited role of artificially created gaps as places favouring seedlings establishment.