Influential factors and processes in post-fire spatial changes of soil seed banks structure in Mediterranean saline steppe

Abstract

Mediterranean saline steppes hold plant communities adapted to saline soils and severe droughts, with a spatial structure tipycal of semi-arid environments: vegetation is distributed in multi-specific patches on a large bare-soil matrix. Such a structure exerts a strong effect on spatio-temporal patterns of the soil seed bank, which tends to accumulate under plant patches. In this study, we evaluated the recover ability of soil seed banks and possible changes in their spatial patterns during the earliest post-fire phases in a saline steppe, when the extant vegetation was temporally removed in the habitat. The study was carried out in El Saladar de Cordovilla (Tobarra, Albacete) after a fire in the late summer of 2011. To do this we proceeded to track and collect soil samples during the subsequent year and a half to fire. The seed in samples were identified and the results were subjected to various statistical analyses. The results showed that 18 months were not enough to recovery the original composition of soil seed bank in continental saline steppes, because after a fire the plant patches structure disappear temporarily, at least from original places, so their effect on spatial patterns of soil seed bank distribution are temporarily deleted.

Keywords

• parches de vegetación
• microhábitats
• sucesión secundaria.