Effect of burning of evergreen savin juniper and herbaceous patches on soil: Seed banks, chemical and biological properties

The coniferous shrub species Juniperus sabina (savin) is widespread in mountainous regions of Eurasia. The species produces large amounts of fire-prone plant mass in its habitats. The aim of this study was to assess the effect that burning of savin shrubs has on the soil seed bank (SSB), the microbial respiration and the amount of organic matter under its canopy. In each of three sampling areas, four individuals of savin were randomly selected. Under each of these individuals and on adjacent herbaceous control patches, soil samples were taken from 0 to 5 cm and 5-10 cm depths for SSB, biological and chemical analyses. The sampling was repeated after burning the canopy. We found that the immediate effects of burning on the SSB and on the biological and chemical soil parameters were significantly negative. In particular, SSB density, magnitude of microbial respiration and amount of organic matter were significantly decreased after savin canopy burning in 0-5 cm depth, while these changes were less pronounced on the burned herbaceous patches. Hence the restoration of gaps created by burning savin cannot rely on the SSB. Furthermore, alkalization of the soil and decreased soil quality caused by savin burning might hamper the vegetation recovery even in the medium to long run.